INFLUENCE OF HUMAN CHORIONIC GONADOTROPHIN ON THE RESPONSE OF LUTEINIZING HORMONE TO LUTEINIZING HORMONE RELEASING HORMONE IN GONADECTOMIZED WOMEN

1977 ◽  
Vol 74 (3) ◽  
pp. 499-500 ◽  
Author(s):  
A. MIYAKE ◽  
T. AONO ◽  
O. TANIZAWA ◽  
T. KINUGASA ◽  
K. KURACHI
Keyword(s):  
Luteinizing Hormone ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone

INHIBITION BY MELATONIN OF THE PITUITARY RESPONSE TO LUTEINIZING HORMONE RELEASING HORMONE IN VIVO

1978 ◽  
Vol 76 (3) ◽  
pp. 487-491 ◽  
Author(s):  
K. YAMASHITA ◽  
M. MIENO ◽  
T. SHIMIZU ◽  
ER. YAMASHITA
Keyword(s):  
Luteinizing Hormone ◽  
Carotid Artery ◽  
Anterior Pituitary ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Rh ◽  
Lh Secretion

The rate of secretion of 17-oxosteroids by the testes of anaesthetized dogs in vivo was used as an index of LH secretion. Intracarotid injection of luteinizing hormone releasing hormone (LH-RH, 1, 5 or 10 μg/kg body wt) resulted in an increase in the testicular 17-oxosteroid secretion which was roughly proportional to the dose administered and which reached a maximum 60 min after the injection. Testicular output of 17-oxosteroids was unaffected by administration of melatonin (10 or 100 μg/kg body wt) into the carotid artery. When LH-RH (5 μg/kg) was injected into the carotid artery 3 h after intracarotid injection of melatonin (10 or 100 μg/kg), the testicular response to LH-RH was considerably diminished. Pretreatment with melatonin (100 μg/kg) did not alter the testicular response to human chorionic gonadotrophin (20 i.u./kg body wt) given i.v. It is concluded that melatonin may act directly on the anterior pituitary gland in dogs to inhibit the LH-RH-induced release of LH.

MECHANISM OF THE SELECTIVE SURGE OF FOLLICLE-STIMULATING HORMONE IN DIOESTROUS RATS DURING THE INDUCTION OF OVULATION BY HUMAN CHORIONIC GONADOTROPHIN

1980 ◽  
Vol 86 (3) ◽  
pp. 489-495 ◽  
Author(s):  
SHUJI SASAMOTO ◽  
KAZUYOSHI TAYA
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Time Of Day ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Normal Cycle ◽  
Luteinizing Hormone Releasing Hormone ◽  
Immature Rats ◽  
Lh Release ◽  
Lh Rh

A selective surge of FSH with a small concomitant rise in LH occurred invariably in rats when ovulation was induced by injecting human chorionic gonadotrophin (HCG) at various reproductive stages such as day 15 of lactation and in 29-day-old immature rats as well as in dioestrous animals. No FSH surge occurred on day 3 of lactation or in 26-day-old immature rats in which ovulation could not be induced by HCG. The FSH surge occurred 6–18 h after HCG treatment regardless of the time of day of injection of HCG. Ovulation began by 12 h and was completed by 18 h after injection of HCG. Pituitary responsiveness to luteinizing hormone releasing hormone (LH-RH) with respect to FSH release strikingly increased at 01.00 h on day 1 after HCG injection at 17.00 h of dioestrus (day 0) to levels similar to those of the group at 01.00 h of oestrus, when the greatest response was noted during the normal cycle. With regard to LH release pituitary responsiveness to LH-RH at 01·00 h on day 1 markedly increased but the response was only about half of the response at 01·00 h of oestrus and one third of the response at 17.00 h of pro-oestrus when the greatest response was noted during the normal oestrous cycle. These results indicate that during ovulation the pituitary gland of the rat is highly responsive to LH-RH with respect to the release of FSH, for which secretory changes in the ovary after an ovulating dose of HCG may be responsible.

THE PRECISION OF THE OVARIAN ASCORBIC ACID DEPLETION TEST FOR LUTEINIZING HORMONE

1963 ◽  
Vol 43 (1) ◽  
pp. 155-160
Author(s):  
Jørgen Falck Larsen ◽  
Christian Hamburger
Keyword(s):  
Ascorbic Acid ◽  
Luteinizing Hormone ◽  
Clinical Analysis ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin

ABSTRACT Various modifications of the Parlow test for luteinizing hormone (ovarian ascorbic acid depletion in rats) were tried. Human chorionic gonadotrophin was used instead of hypophyseal luteinizing hormone. The precision of the method was found to be so low, however, that the test could not be used for routine clinical analysis. The low precision found in this and other laboratories is thought to be due to the strains of rats used.

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