Gerontology 24: 441 -447 (1978)
Human Pituitary Growth Hormone Cells in Old Age Lilian Calderon, Nancy Ryan and Kalman Kovacs1 Department of Pathology, St. Michael’s Hospital, University of Toronto, Toronto, Ont.
Key Words. Human pituitary ■Growth hormone • Histology • Immunocytology Abstract. Pituitaries obtained at autopsy from 18 men and 17 women, over 80 years of age, who died of various acute illnesses, were investigated histologically by various staining procedures, including the immunoperoxidase technique. Compared with pituitaries of 10 male and 10 female subjects who died of short-lasting diseases between 20 and 56 years of age, no involution of growth hormone cells was found in pituitaries of the older group. Incidence, distribution, granulation and immunoreactivity of growth hormone cells showed no apparent difference related to age and sex. Lack of regression of grow th hormone cells with advancing age indicates that the pituitary can produce growth hormone in old subjects.
Studies of the morphologic manifestations of growth hormone secretion related to aging yielded equivocal results (Shanklin, 1953; Korenchevsky, 1961; Verzar, 1966). Acidophil cells, the sites of growth hormone production {Baker, 1974; Halmi et al., 1975), were claimed to be increased, reduced or unchanged in number in the pituitaries of subjects who died of various diseases in old age (Rasmussen, 1938; Shanklin, 1953; Verzar, 1966; Haugen, 1973). A gradual decrease of pituitary weight was reported with advancing age in men, whereas no weight reduction was apparent in aging women (Rasmussen, 1928, 1938; Verzar, 1966). Interstitial fibrosis of the anterior pituitary was also noted in senescence (Fazekas and Jobba, 1970). Until recently, reliable techniques for cell identifica-
1 The authors wish to thank Mrs. Wanda Wlodarski for invaluable secretarial work.
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Received: October 10, 1977; accepted: November 23, 1977.
Calderon /Ryan/Kovacs
442
tion were not available, no correlation was established between morphologic changes and functional activity. The introduction of immunocytological methods permitted the specific localization of different hormones in the cell cytoplasm and the separation of various cell types. The immunoperoxidase technique is especially valuable, since it allows the study of formalin-fixed and paraffin-embedded tissues; even autopsy material stored for several years is suitable for demonstrating the presence of immunoreactive hormones (Nieuwenhuyzen Kruseman et al., 1975 ; Ko vacs et ai, 1976). In order to shed light on the morphologic features of growth hormone cells in old age, pituitary glands of male and female subjects who died over 80 years of age have been studied by histology, including the immunoperoxidase tech nique. The results of this investigation are reported in the present paper.
Pituitary glands, obtained from routine autopsies, of 18 male and 17 female subjects who died over 80 years of age have been studied and compared with those of a control group consisting of 10 male and 10 female subjects who died between 20 and 56 years of age (average: 44 years). Cases were selected based on the following three criteria: (1) no pre-existing chronic disease, thus the patients had no previous serious medical problems and died within a few days after admission of bronchopneumonia, myocardial infarction, cerebral infarction or ruptured cerebral aneurysm; (2) absence of apparent endocrine abnor malities, and (3) no treatment with drugs, such as estrogen, thyroxin, insulin, etc., known to interfere with growth hormone synthesis and/or release. After removal from the sella turcica, pituitary glands were fixed in buffered formalin and embedded in paraffin. Sections of 4 - 6 fim thickness were cut from the paraffin blocks which were stored for various lengths of time (up to 15 years) and stained with hematoxylin-phloxine-saffron, PAS, lead hematoxylin, Goldberg-Chaikoffs trichromc, Brookes’ carmoisine and in some cases with hematoxylin-eosine, PAS-orangc-G or PAS-light-green methods. For immunocytological localization of growth hormone the immunoperoxidase tech nique was used as described in detail elsewhere (Kovacs et al., 1976). The antihuman growth hormone was raised in rabbits (Wellcome Reagents Ltd., Beckenham, England), and was used for 1-hour incubation at a dilution of 1:4,000. The horseradish-peroxidase-antihorseradish-peroxidase complex (Cappell Laboratories Inc., Downingtown, Pa.) was applied to demonstrate antigen-antibody binding and 3,3'-diaminobenzidine to visualize the reaction product. For control purposes the primary antibody was replaced by normal rabbit serum, phosphate buffered saline, or serially diluted until positive staining was abolished. The immuno-stained sections were investigated by three independent observers with no previous knowledge of age, sex, clinical history or pathological findings. Since growth hormone cells are unevenly distributed in the anterior lobes, no cell counts were performed. Number of cells staining for immunoreactive growth hormone as well as the intensity of immunostaining were assessed by a semiquantitative scale (++ = normal, as determined by control group; +++= increased; += decreased). Results were expressed as the mean of findings of the three observers.
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Materials and Methods
Growth Hormone Cells in Old Age
443
Results Growth hormone cells are round, ovoid or slightly irregular, and, compared to other adenohypophysial cell types, are of medium size, frequently arranged in clusters and located close to capillaries. They exhibit cytoplasmic staining with various acid dyes, such as eosine, phloxine, orange G or light green, are PAS and lead hematoxylin negative and show no carmoisinophilia, a distinguishing feature of prolactin cells, the other cell type of the acidophil cell line (Halmi et al., 1975; Kovacs et al., 1976). By applying antihuman growth hormone as a specific antibody, growth hormone cells stain distinctly with the immunoperoxidase technique. With low power view, on the immunostained sections, a strong, diffuse cytoplasmic staining is apparent (fig. la), while by using high power lenses the individual cytoplasmic granules can be clearly delineated (fig. 2a). Growth hormone cells, representing the most frequently occurring cell type in the human adenohypophysis, are easily noticeable throughout the entire anterior lobe. They are the predominant cell type in the lateral wings, except for a narrow subcapsular rim in the posterolateral margin, adjacent to the posterior lobe where abundance of growth hormone cells is not conspicuous. In the centrally located mucoid wedge, growth hormone cells occurring singly or arranged in small groups, are less numerous and are intermingled with other adenohypophysial cell types. In the present material, incidence, distribution, cytoplasmic granularity as well as immunoreactivity of growth hormone cells were fairly constant in the various groups, and no apparent differences were noted in relation to age and sex (fig. lb, 2b; table I). There was only a slight variation from case to case, and no definite correlation was noted between number, morphology, hormone storage of growth hormone cells and pathological findings as well as cause of death.
Table I. Incidence and immunoreactivity of pituitary hormone cells in relation to age Number of cases
Growth hormone cells incidence
immunoreactivity
Between 20-56 years Males Females
20 10 10
2.21 2.2 2.2
2.3 2.2 2.3
More than 80 years Males Females
35 18 17
2.0 2.1 1.9
2.3 2.3 2.3
' Mean of findings obtained by three independent observers.
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Subjects
Calderon /R yan/Ko vacs
444
Fig. I. a Numerous growth hormone cells are evident in the lateral wing of the anterior lobe. Pituitary of a 49-year-old woman who died of cerebral hemorrhage. Immunoperoxi dase technique for the demonstration of growth hormone. X 100. b No regression of growth hormone cells is noted in the anterior lobe. Pituitary of an 80-year-old woman who died of bronchopneumonia. Immunoperoxidase technique for the demonstration of growth hor mone. X 100.
Studies dealing with the functional activity of growth hormone cells indi cate that neither pituitary growth hormone content (Gershberg, 1957; Russ.field, 1960) nor basal blood growth hormone levels show significant decrease with advancing age ( Utiger, 1964; Dud! et al., 1973; Blichert-Toft, 1975). However, the nictohemereal variation of blood growth hormone levels is often less pro nounced in elderly than that of younger subjects (Blichert-Toft, 1975). Rise of blood growth hormone levels in response to stress, surgical trauma, exercise, sleep, insulin, arginine or ¿-dopa is also frequently reduced or absent in old patients (Carlson et al., \912\Dudl et al., 1973; Blichert-Toft, 1975; Bazzarre et al., 1976). Although the 24-hour release of growth hormone might be decreased in senescence (Finkelstein et al, 1972; Blichert-Toft, 1975), basal growth
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Discussion
Growth Hormone Cells in Old Age
445
hormone secretion remains unimpaired (Blichert-Toft, 1975) and the endoge nous secretory reserve unaffected by age (Blichert-Toft, 1975). It has been suggested that synthesis and/or release of various hypothalamic stimulatory and inhibitory hormones might be abnormal in old animals (Clemens et al, 1969; Simpkins et al., 1977). Pecile et al. (1965) has found that growth hormone releasing activity detectable in the hypothalami of young rats is decreased in old rats and the pituitary response of old rats to hypothalamic extracts containing growth hormone releasing activity is less pronounced than that of young rats. Although changes in hypothalamic neurotransmitter function might considerably affect the secretory capacity of various adenohypophysial cell types, it appears that in animals growth hormone secretion is not impaired with advancing age ( Yamamoto et al., 1970). In previous studies, conventional staining techniques were used for assessing
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Fig. 2. a Immunoreactive growth hormone is evident in the cytoplasmic secretory granules. Pituitary of a 41-year-old woman who died of cerebral hemorrhage. Immunoper oxidase technique for the demonstration of growth hormone. X 400. b Cytoplasm of growth hormone cells shows a strong granular positivity. Pituitary of a 88-year-old woman who died of cardiac arrest. Immunoperoxidase technique for the demonstration of growth hormone. X 400.
Calderon /Ryan /Kovacs
446
the incidence and morphologic features of growth hormone cells of the human pituitary in old age (Rasmussen, 1938; Verzâr, 1966; Haugen, 1973). To our knowledge, this investigation is the first which deals with these problems, by applying the immunoperoxidase technique. By using immunofluorescence, Pasteels et al. (1972) found no obvious differences in growth hormone cells in relation to age and sex. Since no regression of growth hormone cells was revealed in aging subjects in our study, it is conceivable that the pituitary is capable of secreting growth hormone in old age. It is also reasonable to suggest that factors regulating production and release of growth hormone, continue to function in senescence. Similar conclusions were reported in relation to prolactin cells which also showed no involution in the pituitaries of male and female subjects who died over 80 years of age {Kovacs et ai, 1977). References
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Baker, B.L.: Functional cytology of the hypophysial pars distalis and pars intermedia; in Creep and Astwood Handbook of physiology, section 7: Endocrinology, vol. 4, part 1, pp. 45 -8 0 (Am. Physiol. Soc., Washington 1974). Bazzarre, T.L.; Johanson, A.J.; Huseman, C.A.; Varma, M.M., and Blizzard, R.M.: Human growth hormone changes with age; in Pecile and Muller Growth hormone and related peptides, Proc. 3rd Int. Symp., Milan 1975, pp. 261-270 (Exccrpta Mcdica, Amster dam 1976). Blicliert-Toft, M.: Secretion of corticotrophin and somatotrophin by the senescent adeno hypophysis in man. Acta endocr., Copenh., suppl. 195, pp. 1-157 (1975). Carlson, H.E.; Gillin, J.C.; Gorden, P., and Snyder, F.: Absence of sleep related growth hormone peaks in aged normal subjects and acromegaly. J. clin. Endocr. Metab. 34: 1102-1105 (1972). Clemens, J.A.; Amenomori, Y.; Jenkins, T., and Mettes, J.: Effects of hypothalamic stimulation, hormones and drugs on ovarian function in old female rats. Proc. Soc. exp. Biol. Med. 132: 561-563 (1969). Dudl, R.J.; Ensinck, J.W.; Palmer, H.E., and Williams, R.H.: Effect of age in growth hormone secretion in man. J. clin. Endocr. Metab. 37: 11 16 (1973). Fazekas, I.G. und Jobba, G.: Beitrag zur Morphologie der senilen Hypophyse. Acta morph, hung. 18: 79-89 (1970). Finkelstein, J.W.; Roffwarg, H.P.; Boyer, R.M.; Kream, J., and Heilman, /..: Age-related change in the twenty-four-hour spontaneous secretion of growth hormone. J. clin. Endocr. Metab. 35: 665-670 (1972). Gershberg, H.: Growth hormone content and metabolic actions of human pituitary gland. Endocrinology 61: 160-165 (1957). Halmi, N.S.; Parsons, J.A.; Erlandsen, S.L., and Duello, T.: Prolactin and growth hormone cells in the human hypophysis. A study with immunoenzyme histochemistry and differential staining. Cell Tissue Res. 158: 497-507 (1975). Haugen, O.A.: Distribution of pituitary cell types in relation to the histology of the prostate in elderly men. An analysis in an autopsy series. Acta path, microbiol. scand., section A 81: 411-424 (1973). Korenchevsky, V.: Hypophysis and aging; in Bourne Physiological and pathological aging, chapter 15, pp. 342-364 (Karger, Basel 1961).
Growth Hormone Cells in Old Age
447
Dr. K. Kovacs, Department of Pathology, St. Michael's Hospital, 30 Bond Street, Toronto, Ont. MSB IW8 (Canada)
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Kovacs, K.; Corenblum, B.; Sirek, A.M.T.; Penz, G., and Ezrin, C.: Localization of prolactin in chromophobe pituitary adenomas. Study of human necropsy material by immuno peroxidase technique. J. clin. Path. 29: 250-258 (1976). Kovacs, K.; Ryan, N.; Horvath, E.; Penz, G., and Ezrin, C.: Prolactin cells of the human pituitary gland in old age. J. Geront. 32: 534-540 (1977). Nieuwenhuyzen Kruseman, A.C.; Bots, G.T.A.M., and I,indeman, E.: The immunohisto chemical identification of hormone-producing cells in formalin-fixed, paraffinembedded human pituitary tissue. J. Path. Bact. 117: 163-168 (1975). Pasteels, J.L.; Gousset, P.: Danguay, A.; Ectors, F.; Nicoll, C.S., and Varavudhi, P.: Morphology of the lactotropes and somatotropes of man and Rhesus monkeys. J. clin. Endocr. Metab. 34: 959-967 (1972). Pecile, A.; Miiller, E.; Falconi, G., and Martini, I,.: Growth hormone-releasing activity of hypothalamic extracts at different ages. Endocrinology 77: 241-246 (1965). Rasmussen, A.T.: The weight of the principal components of the normal male adult human hypophysis cerebri. Am. J. Anat. 42: 1-27 (1928). Rasmussen, A.T.: The proportions of the various subdivisions of the normal adult human hypophysis cerebri and the relative number of the different types of cells in pars distalis, with biometric evaluation of age and sex differences and special consideration of basophilic invasion into the infundibular process. Res. Pubis Ass. Res. nerv. ment. Dis. 17: 118-150 (1938). Russfield, A.B.: Combined bioassay and histological study of 73 human hypophyses. Cancer, N.Y. 13: 790-803 (1960). Shanklin, W.M.: Age changes in the histology of the human pituitary. Acta anat. 19: 290-304 (1953). Simpkins, J. W.; Mueller, G.P.; Huang, H.H., and Meites, J.- Evidence for depressed catechol amine and enhanced serotonin metabolism in aging male rats. Possible relation to gonadotropin secretion. Endocrinology 100: 1672-1678 (1977). Utiger, R.D.: Extraction and radioimmunoassay of growth hormone in human serum. J. clin. Endocr. Metab. 24: 60-67 (1964). Verzàr, F.: Anterior pituitary function in age; in Harris and Donovan The pituitary gland, vol. 2, pp. 444-459 (Butterworths, London 1966). Yamamoto, K.; Taylor, L.M., and Cole, F'.E.: Synthesis and release of GH and prolactin from the rat anterior pituitary in vitro as functions of age and sex. Endocrinology 87: 21-26 (1970).
Human Pituitary Growth Hormone Cells in Old Age Lilian Calderon, Nancy Ryan and Kalman Kovacs1 Department of Pathology, St. Michael’s Hospital, University of Toronto, Toronto, Ont.
Key Words. Human pituitary ■Growth hormone • Histology • Immunocytology Abstract. Pituitaries obtained at autopsy from 18 men and 17 women, over 80 years of age, who died of various acute illnesses, were investigated histologically by various staining procedures, including the immunoperoxidase technique. Compared with pituitaries of 10 male and 10 female subjects who died of short-lasting diseases between 20 and 56 years of age, no involution of growth hormone cells was found in pituitaries of the older group. Incidence, distribution, granulation and immunoreactivity of growth hormone cells showed no apparent difference related to age and sex. Lack of regression of grow th hormone cells with advancing age indicates that the pituitary can produce growth hormone in old subjects.
Studies of the morphologic manifestations of growth hormone secretion related to aging yielded equivocal results (Shanklin, 1953; Korenchevsky, 1961; Verzar, 1966). Acidophil cells, the sites of growth hormone production {Baker, 1974; Halmi et al., 1975), were claimed to be increased, reduced or unchanged in number in the pituitaries of subjects who died of various diseases in old age (Rasmussen, 1938; Shanklin, 1953; Verzar, 1966; Haugen, 1973). A gradual decrease of pituitary weight was reported with advancing age in men, whereas no weight reduction was apparent in aging women (Rasmussen, 1928, 1938; Verzar, 1966). Interstitial fibrosis of the anterior pituitary was also noted in senescence (Fazekas and Jobba, 1970). Until recently, reliable techniques for cell identifica-
1 The authors wish to thank Mrs. Wanda Wlodarski for invaluable secretarial work.
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Received: October 10, 1977; accepted: November 23, 1977.
Calderon /Ryan/Kovacs
442
tion were not available, no correlation was established between morphologic changes and functional activity. The introduction of immunocytological methods permitted the specific localization of different hormones in the cell cytoplasm and the separation of various cell types. The immunoperoxidase technique is especially valuable, since it allows the study of formalin-fixed and paraffin-embedded tissues; even autopsy material stored for several years is suitable for demonstrating the presence of immunoreactive hormones (Nieuwenhuyzen Kruseman et al., 1975 ; Ko vacs et ai, 1976). In order to shed light on the morphologic features of growth hormone cells in old age, pituitary glands of male and female subjects who died over 80 years of age have been studied by histology, including the immunoperoxidase tech nique. The results of this investigation are reported in the present paper.
Pituitary glands, obtained from routine autopsies, of 18 male and 17 female subjects who died over 80 years of age have been studied and compared with those of a control group consisting of 10 male and 10 female subjects who died between 20 and 56 years of age (average: 44 years). Cases were selected based on the following three criteria: (1) no pre-existing chronic disease, thus the patients had no previous serious medical problems and died within a few days after admission of bronchopneumonia, myocardial infarction, cerebral infarction or ruptured cerebral aneurysm; (2) absence of apparent endocrine abnor malities, and (3) no treatment with drugs, such as estrogen, thyroxin, insulin, etc., known to interfere with growth hormone synthesis and/or release. After removal from the sella turcica, pituitary glands were fixed in buffered formalin and embedded in paraffin. Sections of 4 - 6 fim thickness were cut from the paraffin blocks which were stored for various lengths of time (up to 15 years) and stained with hematoxylin-phloxine-saffron, PAS, lead hematoxylin, Goldberg-Chaikoffs trichromc, Brookes’ carmoisine and in some cases with hematoxylin-eosine, PAS-orangc-G or PAS-light-green methods. For immunocytological localization of growth hormone the immunoperoxidase tech nique was used as described in detail elsewhere (Kovacs et al., 1976). The antihuman growth hormone was raised in rabbits (Wellcome Reagents Ltd., Beckenham, England), and was used for 1-hour incubation at a dilution of 1:4,000. The horseradish-peroxidase-antihorseradish-peroxidase complex (Cappell Laboratories Inc., Downingtown, Pa.) was applied to demonstrate antigen-antibody binding and 3,3'-diaminobenzidine to visualize the reaction product. For control purposes the primary antibody was replaced by normal rabbit serum, phosphate buffered saline, or serially diluted until positive staining was abolished. The immuno-stained sections were investigated by three independent observers with no previous knowledge of age, sex, clinical history or pathological findings. Since growth hormone cells are unevenly distributed in the anterior lobes, no cell counts were performed. Number of cells staining for immunoreactive growth hormone as well as the intensity of immunostaining were assessed by a semiquantitative scale (++ = normal, as determined by control group; +++= increased; += decreased). Results were expressed as the mean of findings of the three observers.
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Materials and Methods
Growth Hormone Cells in Old Age
443
Results Growth hormone cells are round, ovoid or slightly irregular, and, compared to other adenohypophysial cell types, are of medium size, frequently arranged in clusters and located close to capillaries. They exhibit cytoplasmic staining with various acid dyes, such as eosine, phloxine, orange G or light green, are PAS and lead hematoxylin negative and show no carmoisinophilia, a distinguishing feature of prolactin cells, the other cell type of the acidophil cell line (Halmi et al., 1975; Kovacs et al., 1976). By applying antihuman growth hormone as a specific antibody, growth hormone cells stain distinctly with the immunoperoxidase technique. With low power view, on the immunostained sections, a strong, diffuse cytoplasmic staining is apparent (fig. la), while by using high power lenses the individual cytoplasmic granules can be clearly delineated (fig. 2a). Growth hormone cells, representing the most frequently occurring cell type in the human adenohypophysis, are easily noticeable throughout the entire anterior lobe. They are the predominant cell type in the lateral wings, except for a narrow subcapsular rim in the posterolateral margin, adjacent to the posterior lobe where abundance of growth hormone cells is not conspicuous. In the centrally located mucoid wedge, growth hormone cells occurring singly or arranged in small groups, are less numerous and are intermingled with other adenohypophysial cell types. In the present material, incidence, distribution, cytoplasmic granularity as well as immunoreactivity of growth hormone cells were fairly constant in the various groups, and no apparent differences were noted in relation to age and sex (fig. lb, 2b; table I). There was only a slight variation from case to case, and no definite correlation was noted between number, morphology, hormone storage of growth hormone cells and pathological findings as well as cause of death.
Table I. Incidence and immunoreactivity of pituitary hormone cells in relation to age Number of cases
Growth hormone cells incidence
immunoreactivity
Between 20-56 years Males Females
20 10 10
2.21 2.2 2.2
2.3 2.2 2.3
More than 80 years Males Females
35 18 17
2.0 2.1 1.9
2.3 2.3 2.3
' Mean of findings obtained by three independent observers.
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Subjects
Calderon /R yan/Ko vacs
444
Fig. I. a Numerous growth hormone cells are evident in the lateral wing of the anterior lobe. Pituitary of a 49-year-old woman who died of cerebral hemorrhage. Immunoperoxi dase technique for the demonstration of growth hormone. X 100. b No regression of growth hormone cells is noted in the anterior lobe. Pituitary of an 80-year-old woman who died of bronchopneumonia. Immunoperoxidase technique for the demonstration of growth hor mone. X 100.
Studies dealing with the functional activity of growth hormone cells indi cate that neither pituitary growth hormone content (Gershberg, 1957; Russ.field, 1960) nor basal blood growth hormone levels show significant decrease with advancing age ( Utiger, 1964; Dud! et al., 1973; Blichert-Toft, 1975). However, the nictohemereal variation of blood growth hormone levels is often less pro nounced in elderly than that of younger subjects (Blichert-Toft, 1975). Rise of blood growth hormone levels in response to stress, surgical trauma, exercise, sleep, insulin, arginine or ¿-dopa is also frequently reduced or absent in old patients (Carlson et al., \912\Dudl et al., 1973; Blichert-Toft, 1975; Bazzarre et al., 1976). Although the 24-hour release of growth hormone might be decreased in senescence (Finkelstein et al, 1972; Blichert-Toft, 1975), basal growth
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Discussion
Growth Hormone Cells in Old Age
445
hormone secretion remains unimpaired (Blichert-Toft, 1975) and the endoge nous secretory reserve unaffected by age (Blichert-Toft, 1975). It has been suggested that synthesis and/or release of various hypothalamic stimulatory and inhibitory hormones might be abnormal in old animals (Clemens et al, 1969; Simpkins et al., 1977). Pecile et al. (1965) has found that growth hormone releasing activity detectable in the hypothalami of young rats is decreased in old rats and the pituitary response of old rats to hypothalamic extracts containing growth hormone releasing activity is less pronounced than that of young rats. Although changes in hypothalamic neurotransmitter function might considerably affect the secretory capacity of various adenohypophysial cell types, it appears that in animals growth hormone secretion is not impaired with advancing age ( Yamamoto et al., 1970). In previous studies, conventional staining techniques were used for assessing
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Fig. 2. a Immunoreactive growth hormone is evident in the cytoplasmic secretory granules. Pituitary of a 41-year-old woman who died of cerebral hemorrhage. Immunoper oxidase technique for the demonstration of growth hormone. X 400. b Cytoplasm of growth hormone cells shows a strong granular positivity. Pituitary of a 88-year-old woman who died of cardiac arrest. Immunoperoxidase technique for the demonstration of growth hormone. X 400.
Calderon /Ryan /Kovacs
446
the incidence and morphologic features of growth hormone cells of the human pituitary in old age (Rasmussen, 1938; Verzâr, 1966; Haugen, 1973). To our knowledge, this investigation is the first which deals with these problems, by applying the immunoperoxidase technique. By using immunofluorescence, Pasteels et al. (1972) found no obvious differences in growth hormone cells in relation to age and sex. Since no regression of growth hormone cells was revealed in aging subjects in our study, it is conceivable that the pituitary is capable of secreting growth hormone in old age. It is also reasonable to suggest that factors regulating production and release of growth hormone, continue to function in senescence. Similar conclusions were reported in relation to prolactin cells which also showed no involution in the pituitaries of male and female subjects who died over 80 years of age {Kovacs et ai, 1977). References
Downloaded by: King's College London 137.73.144.138 - 1/29/2019 10:35:08 PM
Baker, B.L.: Functional cytology of the hypophysial pars distalis and pars intermedia; in Creep and Astwood Handbook of physiology, section 7: Endocrinology, vol. 4, part 1, pp. 45 -8 0 (Am. Physiol. Soc., Washington 1974). Bazzarre, T.L.; Johanson, A.J.; Huseman, C.A.; Varma, M.M., and Blizzard, R.M.: Human growth hormone changes with age; in Pecile and Muller Growth hormone and related peptides, Proc. 3rd Int. Symp., Milan 1975, pp. 261-270 (Exccrpta Mcdica, Amster dam 1976). Blicliert-Toft, M.: Secretion of corticotrophin and somatotrophin by the senescent adeno hypophysis in man. Acta endocr., Copenh., suppl. 195, pp. 1-157 (1975). Carlson, H.E.; Gillin, J.C.; Gorden, P., and Snyder, F.: Absence of sleep related growth hormone peaks in aged normal subjects and acromegaly. J. clin. Endocr. Metab. 34: 1102-1105 (1972). Clemens, J.A.; Amenomori, Y.; Jenkins, T., and Mettes, J.: Effects of hypothalamic stimulation, hormones and drugs on ovarian function in old female rats. Proc. Soc. exp. Biol. Med. 132: 561-563 (1969). Dudl, R.J.; Ensinck, J.W.; Palmer, H.E., and Williams, R.H.: Effect of age in growth hormone secretion in man. J. clin. Endocr. Metab. 37: 11 16 (1973). Fazekas, I.G. und Jobba, G.: Beitrag zur Morphologie der senilen Hypophyse. Acta morph, hung. 18: 79-89 (1970). Finkelstein, J.W.; Roffwarg, H.P.; Boyer, R.M.; Kream, J., and Heilman, /..: Age-related change in the twenty-four-hour spontaneous secretion of growth hormone. J. clin. Endocr. Metab. 35: 665-670 (1972). Gershberg, H.: Growth hormone content and metabolic actions of human pituitary gland. Endocrinology 61: 160-165 (1957). Halmi, N.S.; Parsons, J.A.; Erlandsen, S.L., and Duello, T.: Prolactin and growth hormone cells in the human hypophysis. A study with immunoenzyme histochemistry and differential staining. Cell Tissue Res. 158: 497-507 (1975). Haugen, O.A.: Distribution of pituitary cell types in relation to the histology of the prostate in elderly men. An analysis in an autopsy series. Acta path, microbiol. scand., section A 81: 411-424 (1973). Korenchevsky, V.: Hypophysis and aging; in Bourne Physiological and pathological aging, chapter 15, pp. 342-364 (Karger, Basel 1961).
Growth Hormone Cells in Old Age
447
Dr. K. Kovacs, Department of Pathology, St. Michael's Hospital, 30 Bond Street, Toronto, Ont. MSB IW8 (Canada)
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Kovacs, K.; Corenblum, B.; Sirek, A.M.T.; Penz, G., and Ezrin, C.: Localization of prolactin in chromophobe pituitary adenomas. Study of human necropsy material by immuno peroxidase technique. J. clin. Path. 29: 250-258 (1976). Kovacs, K.; Ryan, N.; Horvath, E.; Penz, G., and Ezrin, C.: Prolactin cells of the human pituitary gland in old age. J. Geront. 32: 534-540 (1977). Nieuwenhuyzen Kruseman, A.C.; Bots, G.T.A.M., and I,indeman, E.: The immunohisto chemical identification of hormone-producing cells in formalin-fixed, paraffinembedded human pituitary tissue. J. Path. Bact. 117: 163-168 (1975). Pasteels, J.L.; Gousset, P.: Danguay, A.; Ectors, F.; Nicoll, C.S., and Varavudhi, P.: Morphology of the lactotropes and somatotropes of man and Rhesus monkeys. J. clin. Endocr. Metab. 34: 959-967 (1972). Pecile, A.; Miiller, E.; Falconi, G., and Martini, I,.: Growth hormone-releasing activity of hypothalamic extracts at different ages. Endocrinology 77: 241-246 (1965). Rasmussen, A.T.: The weight of the principal components of the normal male adult human hypophysis cerebri. Am. J. Anat. 42: 1-27 (1928). Rasmussen, A.T.: The proportions of the various subdivisions of the normal adult human hypophysis cerebri and the relative number of the different types of cells in pars distalis, with biometric evaluation of age and sex differences and special consideration of basophilic invasion into the infundibular process. Res. Pubis Ass. Res. nerv. ment. Dis. 17: 118-150 (1938). Russfield, A.B.: Combined bioassay and histological study of 73 human hypophyses. Cancer, N.Y. 13: 790-803 (1960). Shanklin, W.M.: Age changes in the histology of the human pituitary. Acta anat. 19: 290-304 (1953). Simpkins, J. W.; Mueller, G.P.; Huang, H.H., and Meites, J.- Evidence for depressed catechol amine and enhanced serotonin metabolism in aging male rats. Possible relation to gonadotropin secretion. Endocrinology 100: 1672-1678 (1977). Utiger, R.D.: Extraction and radioimmunoassay of growth hormone in human serum. J. clin. Endocr. Metab. 24: 60-67 (1964). Verzàr, F.: Anterior pituitary function in age; in Harris and Donovan The pituitary gland, vol. 2, pp. 444-459 (Butterworths, London 1966). Yamamoto, K.; Taylor, L.M., and Cole, F'.E.: Synthesis and release of GH and prolactin from the rat anterior pituitary in vitro as functions of age and sex. Endocrinology 87: 21-26 (1970).
