CLIN. AND EXPER. HYPER. -THEORY AND PRACTICE, A13(5),
991-998 (1991)
Clin Exp Hypertens Downloaded from informahealthcare.com by University of Melbourne on 11/19/14 For personal use only.
CHANGES IN TSH AND 11-DEOXYCORTICOSTERONE(DOC) IN HYPERTENSION
Takeshi Takami, Hiroyuki Ito, Tsuneyuki Suzuki and Kozo Okamoto Department of Pathology, Kinki University School of Medicine, Osaka 589, Japan
Key words: TSH, 11-deoxycorticosterone(DOC),free T3, free T4, M-SHRSP, WKY
ABSTRACT
In order to elucidate the role of thyroid hormones in hypertension, several plasma hormones were chronologically examined using M-SHRSP (malignant SHRSP). In this study, M-SHRSP blood pressure went above 160 m d g at 6 weeks of age. At the same time, both free T3 and free T4 were already higher in M-SHRSP than in WKY. At 8 weeks of age, M-SHRSP blood pressure reached 220 mmHg, and their TSH and DOC were higher than in WKY. On the other hand, M-SHRSP corticosteronewas lower than in WKY. M-SHRSP free T3 and free T4 also decreased momentarily. At 10 weeks of age, M-SHRSP blood pressure reached 250 mmHg, TSH and DOC were higher than in WKY, and their corticosteronewas nearly equal to that of WKY. At 12 weeks of age, M-SHRSP blood pressure went above 250 mmHg. At the same time, their free "3 and free T4 increased and was again higher than in WKY. Therefore, it is quite possible that free T3,free T4, and DOC are closely related to the development and/or maintenance of hypertension in M-SHRSP.
INTRODUCTION Clinically, we have encountered many hypertensive patients with cerebral strokes ( WHO classification Stage III ) who have also had high levels of plasma TSH, DOC, cortisol, and aldosterone. However, the roles of these hormones in essential hypertension and its complication,are still inadequately understood. Taking a model rat already available for the study of hypertension, Okamoto et al.. were able to establish two new strains :SHR (1) and SHRSP (2). From SHRSP, Okamoto et al. further 991 Copyright 0 1991 by Marcel Dekker, Inc.
992
TAKAMI ET A L .
Clin Exp Hypertens Downloaded from informahealthcare.com by University of Melbourne on 11/19/14 For personal use only.
separated animals evidencing precocious severe hypertension at early stage of development and identified these as malignant or precocious SHRSP (M-SHRSP) (3). In an attempt to experimentally clarify the above clinically findings, in this study we examined changes in these and other related hormones in M-SHRSP.
MATERIALS AND METHODS 1. Animals: Six- to 12-week-old male M-SHRSP were compared with age- and sexmatched WKY. All of the animals were inbred strains, kept in air-conditioned rooms in Kinki University School of Medicine Laboratories, which were maintained at temperatures of 23 %.5C with 5 M % humidity, The animals were fed a stock chow diet (SP, Funabashi Co., Ltd., Chiba) and given tap water ad libitum. During the period from mating to lactation, both male and female M-SHRSP were given 60 mgil of hydralazine hydrochloride (Chiba-Geigy Japan Ltd., Osaka) in drinking water. 2. Measurement of blood DES sux: Blood pressures were measured with an automatic rat blood pressure recorder (Model USM-105, Ueda Seisakusho, TOKYO) using the tail pulse pickup method without anesthesia.
3. Blood collection :Blood was collected without anesthesia from the jugular vein. 4. Determination of Dlasma hormones :Plasma TSH was measured by radioimmunoassay using a rat TSH kit supplied by Dr A.F.Parlow (UCLA Medical Center, USA); plasma T3, T4, free T3, free T4, cortisol, corticosterone and DOC were measured by radioimmunoassay. To examine the effects of glucocorticoids on TSH secretion and blood pressure, 5 M-SHRSP and 5 WKY,aged 8 weeks,were intraperitoneally injected with 5 m@g of corticosterone,30 m a g of cortisol, or saline as control. Plasma TSH levels were measured by radioimmunoassay at 30 minutes after injection and blood pressures were measured an additional 30 minutes later.
RESULTS 1. Blood Dressure: Changes in blood pressure are shown in Figure 1. M-SHRSP had a blood pressure of about 160 mmHg at 6 weeks of age, over 220 mmHg at 8 weeks, around 250 mmHg at 10 weeks and around 260 mmHg at 12 weeks. On the other
Clin Exp Hypertens Downloaded from informahealthcare.com by University of Melbourne on 11/19/14 For personal use only.
THYROID HORMONES AND HYPERTENSION
993
0
1 6
7
8
9
10
Age (Weeks) mean f S.E.M.
* Significant difference from W K V (P
991-998 (1991)
Clin Exp Hypertens Downloaded from informahealthcare.com by University of Melbourne on 11/19/14 For personal use only.
CHANGES IN TSH AND 11-DEOXYCORTICOSTERONE(DOC) IN HYPERTENSION
Takeshi Takami, Hiroyuki Ito, Tsuneyuki Suzuki and Kozo Okamoto Department of Pathology, Kinki University School of Medicine, Osaka 589, Japan
Key words: TSH, 11-deoxycorticosterone(DOC),free T3, free T4, M-SHRSP, WKY
ABSTRACT
In order to elucidate the role of thyroid hormones in hypertension, several plasma hormones were chronologically examined using M-SHRSP (malignant SHRSP). In this study, M-SHRSP blood pressure went above 160 m d g at 6 weeks of age. At the same time, both free T3 and free T4 were already higher in M-SHRSP than in WKY. At 8 weeks of age, M-SHRSP blood pressure reached 220 mmHg, and their TSH and DOC were higher than in WKY. On the other hand, M-SHRSP corticosteronewas lower than in WKY. M-SHRSP free T3 and free T4 also decreased momentarily. At 10 weeks of age, M-SHRSP blood pressure reached 250 mmHg, TSH and DOC were higher than in WKY, and their corticosteronewas nearly equal to that of WKY. At 12 weeks of age, M-SHRSP blood pressure went above 250 mmHg. At the same time, their free "3 and free T4 increased and was again higher than in WKY. Therefore, it is quite possible that free T3,free T4, and DOC are closely related to the development and/or maintenance of hypertension in M-SHRSP.
INTRODUCTION Clinically, we have encountered many hypertensive patients with cerebral strokes ( WHO classification Stage III ) who have also had high levels of plasma TSH, DOC, cortisol, and aldosterone. However, the roles of these hormones in essential hypertension and its complication,are still inadequately understood. Taking a model rat already available for the study of hypertension, Okamoto et al.. were able to establish two new strains :SHR (1) and SHRSP (2). From SHRSP, Okamoto et al. further 991 Copyright 0 1991 by Marcel Dekker, Inc.
992
TAKAMI ET A L .
Clin Exp Hypertens Downloaded from informahealthcare.com by University of Melbourne on 11/19/14 For personal use only.
separated animals evidencing precocious severe hypertension at early stage of development and identified these as malignant or precocious SHRSP (M-SHRSP) (3). In an attempt to experimentally clarify the above clinically findings, in this study we examined changes in these and other related hormones in M-SHRSP.
MATERIALS AND METHODS 1. Animals: Six- to 12-week-old male M-SHRSP were compared with age- and sexmatched WKY. All of the animals were inbred strains, kept in air-conditioned rooms in Kinki University School of Medicine Laboratories, which were maintained at temperatures of 23 %.5C with 5 M % humidity, The animals were fed a stock chow diet (SP, Funabashi Co., Ltd., Chiba) and given tap water ad libitum. During the period from mating to lactation, both male and female M-SHRSP were given 60 mgil of hydralazine hydrochloride (Chiba-Geigy Japan Ltd., Osaka) in drinking water. 2. Measurement of blood DES sux: Blood pressures were measured with an automatic rat blood pressure recorder (Model USM-105, Ueda Seisakusho, TOKYO) using the tail pulse pickup method without anesthesia.
3. Blood collection :Blood was collected without anesthesia from the jugular vein. 4. Determination of Dlasma hormones :Plasma TSH was measured by radioimmunoassay using a rat TSH kit supplied by Dr A.F.Parlow (UCLA Medical Center, USA); plasma T3, T4, free T3, free T4, cortisol, corticosterone and DOC were measured by radioimmunoassay. To examine the effects of glucocorticoids on TSH secretion and blood pressure, 5 M-SHRSP and 5 WKY,aged 8 weeks,were intraperitoneally injected with 5 m@g of corticosterone,30 m a g of cortisol, or saline as control. Plasma TSH levels were measured by radioimmunoassay at 30 minutes after injection and blood pressures were measured an additional 30 minutes later.
RESULTS 1. Blood Dressure: Changes in blood pressure are shown in Figure 1. M-SHRSP had a blood pressure of about 160 mmHg at 6 weeks of age, over 220 mmHg at 8 weeks, around 250 mmHg at 10 weeks and around 260 mmHg at 12 weeks. On the other
Clin Exp Hypertens Downloaded from informahealthcare.com by University of Melbourne on 11/19/14 For personal use only.
THYROID HORMONES AND HYPERTENSION
993
0
1 6
7
8
9
10
Age (Weeks) mean f S.E.M.
* Significant difference from W K V (P
