The effect of varying prolactin levels on pituitary luteinizing hormone and follicle-stimulating hormone response to gonadotropin-releasing hormone WILLIAM
N.
BERNARD
CANTOR,
M.D.
S. KALRA,
PH.D.
PUSHPA WILLIAM
SPELLACY,
C. BUHI,
SHARON
A.
Gainesville,
Florida
M.D.
M.S.
BIRK,
R.N.,
B.S.
SeVenty-One women with menstrual irregularities were investigated by measurement of basal plasma estradiol, prolactin, and gonadotropin levels. They were each given an intravenous injection of 100 pg of gonadotropin-releasing hormone (GnRH), and both luteinking hormone (LH) and foliiciestimdating hormone (FSH) were measured for two hours. The women were divided into three groups on the basis of, the prolactin levels: “normal, ” “mild elevation,” and “severe elevation.” For each prolactin group there was no difference in age or estradiol or basal LH and FSH levels. The pituitary response to the GnRH injection was also similar for the three groups. These data suggest that elevated polactin levels do not interfere with pituitav gonadotropin cell function. (AM. J. OBSTET. GYNEIXL. 132: 157, 1978.)
MANY STUDIES have been published on the role of prolactin (hPr) in the reproductive cycle since the development of sensitive and specific radioimmunoassay systems for this hormone. Generally, either these studies have failed to demonstrate a consistent pattern of blood hPr in the ovulatory cycle or they have noted an alteration in the Iuteal phase, which may suggest a function in corpus luteum maintenance.rm6 There have been numerous investigations of pregnant women’-I3 and lactating postpartum women14-23 with the use of gonadotropin-releasing hormone (GnRH) injections and the results show an association between high blood hPr levels and a suppressed response of the pituitary gonadotropin cells. When hPr levels are lowered in galactorrhea-amenorrhea patients with 2- bromo-cu-er-
Table I. Statistical studies of the women in the three hPr groups prior to GnRF testing (N = 71) “NOl?lWl” No. of women Age (yr.): Mean
S.E.M.
‘Mild ebaGn”
%vere ehation”
40
18
13
26.0
24.9
26.7
1.7
2.5
1.5
129.5
Weight (pounds):
Mean S.E.M.
126.0
160.7*
5.8
10.1
13.9
41.2 5.4
43.8 1 I.0
46.7 11.2
Mean
11.7
S.E.M.
1.2
32.2* 1.3
139.7* 21.9
P&zsmu estradiol Mean
(Qg. /ml.):
S.E.M. Pkasma hPr
(ng. fml.):
= Standard error of the mean. *Probability different from “normal” at ~0.01 level.
S.E.M. From the Department U&ersiCy of Florida
of Obstetrics and Gynecology, College of Medicine.
Presented at the Fortieth Annual Meeting of the South Atlantic Association of 0bstetrician.s and Gynecologists, Acapulco, Mexico, January 21-26, 1978. Rep&t requests: Dr. William N. Spelkzcy, De$artment of Obs~trics and Gynecology, University of Florida College of Medicine, Gainesvilk, F10~ida 32610. 0002-9378/78/02132-0157$00.80/O
0
1978
The
C. V. Moshy
Co.
gocryptine, a rise in gonadotropins occurred, which also suggests that hPr has a suppressive effect on the pituitary gland.24-27 Finally, the delay in ovulation noted in nursing postpartum mothers supports the concept that the hyperprolactinemia of breast-feeding suppresses the reproductive cycle.28F 2x 157
158
Spellacy et al.
Table II. Statistical studies of the gonadotropin response to women with normal plasma hPr levels (N = 40)
September Am. 1. Obstet.
1.5, 1978 Gynecol.
0.25 hl.
to 100 Fg of GnRF given intravenously
LH
Mean S.E.M. t P
Fasting
0.25 hr.
0.5 hr.
0.75 hr.
I hr.
1.5 hr.
2 hr.
Fasting
27.5 6.0 -
97.6 16.3 5.18
N.
BERNARD
CANTOR,
M.D.
S. KALRA,
PH.D.
PUSHPA WILLIAM
SPELLACY,
C. BUHI,
SHARON
A.
Gainesville,
Florida
M.D.
M.S.
BIRK,
R.N.,
B.S.
SeVenty-One women with menstrual irregularities were investigated by measurement of basal plasma estradiol, prolactin, and gonadotropin levels. They were each given an intravenous injection of 100 pg of gonadotropin-releasing hormone (GnRH), and both luteinking hormone (LH) and foliiciestimdating hormone (FSH) were measured for two hours. The women were divided into three groups on the basis of, the prolactin levels: “normal, ” “mild elevation,” and “severe elevation.” For each prolactin group there was no difference in age or estradiol or basal LH and FSH levels. The pituitary response to the GnRH injection was also similar for the three groups. These data suggest that elevated polactin levels do not interfere with pituitav gonadotropin cell function. (AM. J. OBSTET. GYNEIXL. 132: 157, 1978.)
MANY STUDIES have been published on the role of prolactin (hPr) in the reproductive cycle since the development of sensitive and specific radioimmunoassay systems for this hormone. Generally, either these studies have failed to demonstrate a consistent pattern of blood hPr in the ovulatory cycle or they have noted an alteration in the Iuteal phase, which may suggest a function in corpus luteum maintenance.rm6 There have been numerous investigations of pregnant women’-I3 and lactating postpartum women14-23 with the use of gonadotropin-releasing hormone (GnRH) injections and the results show an association between high blood hPr levels and a suppressed response of the pituitary gonadotropin cells. When hPr levels are lowered in galactorrhea-amenorrhea patients with 2- bromo-cu-er-
Table I. Statistical studies of the women in the three hPr groups prior to GnRF testing (N = 71) “NOl?lWl” No. of women Age (yr.): Mean
S.E.M.
‘Mild ebaGn”
%vere ehation”
40
18
13
26.0
24.9
26.7
1.7
2.5
1.5
129.5
Weight (pounds):
Mean S.E.M.
126.0
160.7*
5.8
10.1
13.9
41.2 5.4
43.8 1 I.0
46.7 11.2
Mean
11.7
S.E.M.
1.2
32.2* 1.3
139.7* 21.9
P&zsmu estradiol Mean
(Qg. /ml.):
S.E.M. Pkasma hPr
(ng. fml.):
= Standard error of the mean. *Probability different from “normal” at ~0.01 level.
S.E.M. From the Department U&ersiCy of Florida
of Obstetrics and Gynecology, College of Medicine.
Presented at the Fortieth Annual Meeting of the South Atlantic Association of 0bstetrician.s and Gynecologists, Acapulco, Mexico, January 21-26, 1978. Rep&t requests: Dr. William N. Spelkzcy, De$artment of Obs~trics and Gynecology, University of Florida College of Medicine, Gainesvilk, F10~ida 32610. 0002-9378/78/02132-0157$00.80/O
0
1978
The
C. V. Moshy
Co.
gocryptine, a rise in gonadotropins occurred, which also suggests that hPr has a suppressive effect on the pituitary gland.24-27 Finally, the delay in ovulation noted in nursing postpartum mothers supports the concept that the hyperprolactinemia of breast-feeding suppresses the reproductive cycle.28F 2x 157
158
Spellacy et al.
Table II. Statistical studies of the gonadotropin response to women with normal plasma hPr levels (N = 40)
September Am. 1. Obstet.
1.5, 1978 Gynecol.
0.25 hl.
to 100 Fg of GnRF given intravenously
LH
Mean S.E.M. t P
Fasting
0.25 hr.
0.5 hr.
0.75 hr.
I hr.
1.5 hr.
2 hr.
Fasting
27.5 6.0 -
97.6 16.3 5.18
