scholarly journals Evaluation of GnRH administration on the prolactin response to thyrotrophin-releasing hormone in normal women.

1986 ◽  
Vol 33 (4) ◽  
pp. 511-517 ◽  
Author(s):  
HISANORI MINAKAMI ◽  
KOZO KIMURA ◽  
KUNIHIKO IJIMA ◽  
AKIO AKABORI ◽  
TARO TAMADA
Keyword(s):  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Normal Women ◽  
Prolactin Response

Combined pyridostigmine–thyrotrophin-releasing hormone test for the evaluation of hypothalamic somatostatinergic activity in healthy normal men

1995 ◽  
Vol 133 (4) ◽  
pp. 457-462 ◽  
Author(s):  
Inmyung Yang ◽  
Jeongtaek Woo ◽  
Sungwoon Kim ◽  
Jinwoo Kim ◽  
Youngseol Kim ◽  
...  
Keyword(s):  
Internal Medicine ◽  
Growth Hormone ◽  
Large Dose ◽  
Trh Test ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
School Of Medicine ◽  
Prolactin Response ◽  
Normal Men ◽  
Different Doses

Yang I, Woo J, Kim S, Kim J, Kim Y, Choi Y. Combined pyridostigmine–thyrotrophin-releasing hormone test for the evaluation of hypothalamic somatostatinergic activity in healthy normal men. Eur J Endocrinol 1995;133:457–62. ISSN 0804–4643 Pyridostigmine (PST), a cholinesterase inhibitor, induces a clear growth hormone (GH) release in man by suppression of hypothalamic somatostatin (SRIH). Somatostatin suppresses thyrotrophin (TSH) release in rats and men. Earlier studies showed that the thryotrophin-releasing hormone (TRH)-induced TSH response was not altered by 60–120 mg of PST. We studied whether a larger dose (180 mg) of PST can increase the TSH response to TRH. Six healthy young men were studied with the following six tests: (Test 1) 200 μg of TRH iv; (Test 2) 180 mg of PST po; (Test 3) three different doses of PST (60, 120, 180 mg) + TRH; (Test 4) 100 μg of octreotide (SMS) iv; (Test 5) SMS + TRH; (Test 6) PST + SMS + TRH. A large dose of PST (180 mg) significantly augmented GH, TSH and prolactin responses to TRH, while smaller doses of PST (60 and 120 mg) did not significantly increase the responses of GH and TSH. While the increased TRH-induced prolactin response by PST was not suppressed by SMS, the increased responses of GH and TSH were suppressed remarkably by SMS. Most of the subjects noticed a mild to moderate abdominal pain, nausea and muscular fasciculation after the administration of a large dose of PST administration. These data suggest that suppression of hypothalamic SRIH secretion by 180 mg of PST can augment the TSH response to TRH. However, the considerable side effects should be minimized before clinical application of the combined PST–TRH test. Inmyung Yang, Division of Endocrinology, Department of Internal Medicine, Kyunghee University School of Medicine, 1 Hoiki-dong, Dongdaemoon-ku, Seoul, 130–702, Korea

PITUITARY HORMONE RESPONSES TO HYPOTHALAMIC RELEASING HORMONES IN ACROMEGALY

1976 ◽  
Vol 83 (4) ◽  
pp. 673-683 ◽  
Author(s):  
L. Cantalamessa ◽  
E. Reschini ◽  
A. Catania ◽  
G. Giustina
Keyword(s):  
Clinical Signs ◽  
Pituitary Function ◽  
Pituitary Hormone ◽  
Repeated Testing ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Prolactin Response ◽  
Plasma Gh ◽  
Lh Rh ◽  
Pituitary Irradiation

ABSTRACT The pituitary reserve of GH, prolactin, TSH, LH, and FSH has been studied in a group of 13 acromegalic patients with the aim of evaluating the pituitary function and the activity of the disease. Plasma GH, TSH and prolactin were determined after thyrotrophin releasing hormone (TRH) administration, plasma gonadotrophins and GH after luteinizing hormone releasing hormone (LH-RH) administration. The plasma TSH response to TRH was generally blunted in the patients treated with pituitary irradiation; however, none of the patients with diminished TSH reserve had signs of hypothyroidism. Six acromegalics showed prolactin basal levels higher than controls; none had galactorrhoea; 4 of them complained of impairment of the gonadal function. The prolactin response to TRH was variable and not related to prolactin basal levels. A subnormal LH reserve after LH-RH stimulation was observed in 5 out of 10 patients; 4 of them had also clinical signs of hypogonadism. A normal FSH response to LH-RH was present in all patients. A non-specific GH response to TRH and/or LH-RH was obtained in about half of the acromegalics studied. The GH responsiveness to TRH and/or LH-RH was not related to the activity of the disease or to a specific derangement of the hypothalamo-pituitary function. A concordant response was observed only between GH and prolactin response to TRH; the highest prolactin responses to TRH were obtained in the GH responsive patients. Each patient showed a constant GH pattern of response on repeated testing. Even after pituitary irradiation the pattern of GH response was unchanged in spite of lowered GH plasma levels.

Effects of hypothyroidism on the growth hormone axis in sheep

1994 ◽  
Vol 140 (3) ◽  
pp. 495-502 ◽  
Author(s):  
T P Fletcher ◽  
I J Clarke
Keyword(s):  
Growth Hormone ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Pulse Interval ◽  
Short Term ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Prolactin Response ◽  
Plasma Gh

Abstract This study examined the effect of thyroidectomy (TX) on the GH axis in sheep. The secretion of GH was monitored 10 and 77 days after TX or sham-TX when the effects on plasma GH and prolactin levels of the injection of 0·5 μg GH-releasing factor (GRF)/kg and 1 μg thyrotrophin-releasing hormone (TRH)/kg were also assessed. There were no significant differences in GH pulse amplitude, pulse frequency, inter-pulse interval and GH secreted/h between sham-TX and TX animals at 10 or 77 days after TX. There was no difference in the GH response to GRF injection in sham-TX sheep at any time but in TX sheep the GH response was significantly (P<0·05) attenuated 10 days after TX. After 77 days the GH response was similar to the response before TX. There was no measurable GH response to injection of TRH in sham-operated or TX sheep at any time. The prolactin response to TRH was not affected by TX or sham-TX. These results suggest that TX in sheep does not affect GH secretion but paradoxically the response to GRF is attenuated in hypothyroid sheep in the short term. TRH causes release of prolactin but not GH in sheep. Journal of Endocrinology (1994) 140, 495–502

PROLACTIN RESPONSE TO THYROTROPHIN RELEASING HORMONE IN THYROTOXICOSIS

1974 ◽  
Vol 61 (3) ◽  
pp. 515-516 ◽  
Author(s):  
A. D. TOFT ◽  
A. R. BOYNS ◽  
E. N. COLE ◽  
W. J. IRVINE
Keyword(s):  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Prolactin Response

Effect of immunoneutralization of thyrotrophin-releasing hormone on the release of thyrotrophin and prolactin during suckling or in response to electrical stimulation of the hypothalamus in the anaesthetized rat

1985 ◽  
Vol 106 (1) ◽  
pp. 113-119 ◽  
Author(s):  
W. J. Sheward ◽  
H. M. Fraser ◽  
G. Fink
Keyword(s):  
Electrical Stimulation ◽  
Neural Control ◽  
Brain Area ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Plasma Prolactin ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Prolactin Response ◽  
Stimulation Of

ABSTRACT The aim of the present study was to use the technique of immunoneutralization with anti-thyrotrophin-releasing hormone (anti-TRH) serum to investigate the role of TRH in mediating the TSH and prolactin responses to electrical stimulation of the hypothalamus and the prolactin response to suckling in lactating rats. Electrical stimulation of either the median eminence or paraventricular nuclei of male or female rats anaesthetized with urethane resulted in significant increases in the plasma concentrations of both TSH and prolactin. Injection of sheep anti-TRH serum blocked the rise in plasma TSH concentration in response to stimulation of either brain area, but did not block the increase in plasma prolactin concentration. In anaesthetized, lactating female rats, the suckling stimulus produced a significant increase in the plasma prolactin concentration, but did not alter the plasma TSH concentration. Injection of anti-TRH serum, but not control non-immune or anti-bovine serum albumin, significantly decreased the basal release of TSH but did not abolish the prolactin response to suckling. These results show that TRH is the principal mediator of the neural control of TSH release in the rat, but is not crucial for the release of prolactin in response to either hypothalamic stimulation or suckling. J. Endocr. (1985) 106, 113–119

Desensitization of rat anterior pituitary gland to thyrotrophin releasing hormone

1984 ◽  
Vol 101 (1) ◽  
pp. 101-105 ◽  
Author(s):  
M. C. Sheppard ◽  
K. I. J. Shennan
Keyword(s):  
Anterior Pituitary ◽  
Prolactin Secretion ◽  
Normal Medium ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Pituitary Tissue ◽  
Subsequent Response ◽  
Pituitary Glands ◽  
Prolactin Response

ABSTRACT We have studied the secretion of TSH and prolactin from perifused rat anterior pituitary glands in vitro in response to single pulses of thyrotrophin releasing hormone (TRH) and KCl after prior exposure to TRH. Anterior pituitary fragments were incubated in normal medium or in medium containing 28 nmol TRH/1 for 20 h before perifusion. Thyrotrophin releasing hormone (28 nmol/l), administered as a 3-min pulse, stimulated TSH and prolactin release from control tissue to a peak value four or five times that of basal. After exposure of the pituitary tissue to TRH for 20 h, the subsequent response of TSH to a 3-min pulse of TRH was, however, markedly reduced; in contrast, the prolactin response was not significantly reduced. In a similar series of experiments KCl (60 nmol/l) was administered to both control and TRH-'treated' pituitary tissue as a 3-min pulse; no significant differences in TSH responses or prolactin responses were observed. These data indicate that TRH desensitizes the pituitary thyrotroph to a subsequent TRH stimulus but has very little effect on prolactin secretion. J. Endocr. (1984) 101, 101–105

Periovulatory plasma prolactin response to synthetic growth hormone-releasing hormone in normal women

Metabolism ◽  
1989 ◽  
Vol 38 (3) ◽  
pp. 275-277 ◽  
Author(s):  
L. De Marinis ◽  
A. Mancini ◽  
C. D'Amico ◽  
P. Sambo ◽  
A. Tofani ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Plasma Prolactin ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Normal Women ◽  
Prolactin Response ◽  
Synthetic Growth
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