Diurnal Influences on Serum Luteinizing Hormone Responses to Opiate Receptor Blockade with Naloxone or to Luteinizing Hormone-Releasing Hormone in the Immature Female Rat

1981 ◽  
Vol 168 (3) ◽  
pp. 338-343 ◽  
Author(s):  
M. S. Blank ◽  
D. R. Mann
Keyword(s):  
Luteinizing Hormone ◽  
Opiate Receptor ◽  
Receptor Blockade ◽  
Female Rat ◽  
Immature Female ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Serum Luteinizing Hormone ◽  
Hormone Responses

SERUM LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE CONCENTRATIONS IN IMMATURE FEMALE RATS TREATED WITH MULTIPLE INJECTIONS AND VARIOUS AMOUNTS OF LUTEINIZING HORMONE RELEASING HORMONE

1975 ◽  
Vol 66 (1) ◽  
pp. 13-20 ◽  
Author(s):  
D. C. JOHNSON ◽  
R. S. MALLAMPATI
Keyword(s):  
Luteinizing Hormone ◽  
Constant Stimulus ◽  
Female Rats ◽  
Intact Female ◽  
Immature Female ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Lh Rh

SUMMARY Release of immunoreactive LH and FSH was induced in immature intact female rats by repeated injections of synthetic luteinizing hormone releasing hormone (LH-RH). Altering the dose of LH-RH (5, 10, 20, 50 ng) and the frequency of administration (every 10, 20, 30 or 60 min) over a period of 2 h produced a variety of serum LH and FSH concentrations and ratios. When the dose was a constant 20 ng but the frequency of injections was either 20 or 30 min, a steady state in serum gonadotrophin concentrations was reached within 1 h and the level remained the same during the second hour. When given every 10 min, 20 ng LH-RH produced a much higher concentration of both LH and FSH during the second hour of stimulation. Examination of the gonadotrophin levels after each injection of LH-RH showed that the pituitary response was variable in spite of a constant stimulus.

Luteinizing hormone responses to luteinizing hormone releasing hormone (LHRH) in acute mania and the effects of lithium on LHRH and thyrotrophin releasing hormone tests in volunteers

1989 ◽  
Vol 19 (1) ◽  
pp. 69-77 ◽  
Author(s):  
R. Hunter ◽  
J. E. Christie ◽  
L. J. Whalley ◽  
J. Bennie ◽  
S. Carroll ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Thyroid Stimulating Hormone ◽  
Thyrotrophin Releasing Hormone ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Trh Stimulation ◽  
The Status ◽  
Hormone Responses ◽  
Independent Features ◽  
Stimulating Hormone

SynopsisThe endocrine responses to Luteinizing Hormone Releasing Hormone (LHRH) of eight drug-free males with mania were determined. Basal levels of Luteinizing Hormone (LH) and the plasma levels following injection of LHRH were elevated in patients compared with controls; Follicle Stimulating Hormone (FSH) and testosterone were not different. Elevated levels of LH have been described previously in recovered manic patients and have been suggested to be state-independent features of mania. In order to clarify the status of this finding, the effects of lithium administration upon hormone responses to LHRH in six male volunteers were also investigated, together with the effects upon Thyrotrophin Releasing Hormone (TRH) stimulation of Thyroid Stimulating Hormone (TSH) and prolactin release. Lithium increased the basal levels of LH and levels after injection of LHRH without effect upon FSH and testosterone. Lithium also increased basal and TRH stimulated release of TSH and basal prolactin levels. Lithium was without effect upon prolactin responses to TRH. The results are discussed in relation to current information on the mechanism of lithium's action. The implications for neuroendocrine work on recovered patients taking lithium are also explored.

THE PRESENCE OF PEPTIDASES IN THE RAT HYPOTHALAMUS INACTIVATING LUTEINIZING HORMONE RELEASING HORMONE (LH-RH)

1974 ◽  
Vol 77 (3) ◽  
pp. 435-442 ◽  
Author(s):  
E. C. Griffiths ◽  
K. C. Hooper ◽  
S. L. Jeffcoate ◽  
D. T. Holland
Keyword(s):  
Luteinizing Hormone ◽  
Reproductive Function ◽  
Assay Method ◽  
Supernatant Fraction ◽  
Peptidase Activity ◽  
Female Rat ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Rat Hypothalamus ◽  
Lh Rh

ABSTRACT The presence of peptidases in the rat hypothalamus inactivating luteinizing hormone-releasing hormone (LH-RH) has previously been demonstrated using an indirect assay method. With the development of a sensitive and specific radioimmunoassay for the releasing hormone, this technique was employed in the study of the peptidases inactivating LH-RH. It was found that supernatant fractions from both male and female rat hypothalami rapidly inactivated LH-RH, and that the peptidase activity of the supernatant fraction was higher in male than in female animals though the particulate fraction's activity was about the same in both sexes. Peptidase activity was also considerably greater in the supernatant than in the particulate fraction. These results confirm that the hypothalamus contains peptidases capable of inactivating LH-RH and give a direct indication that the enzymes may be involved in the central nervous system's control of reproductive function.

Sign in / Sign up

Export Citation Format

Share Document