Recovery of Pituitary-Gonadal Function in Male and Female Rats after Prolonged Administration of a Potent Antagonist of Luteinizing Hormone-Releasing Hormone (SB-75)

1991 ◽  
Vol 54 (2) ◽  
pp. 136-145 ◽  
Author(s):  
Lazaro Bokser ◽  
Gordan Srkalovic ◽  
Karoly Szepeshazi ◽  
Andrew V. Schally
Keyword(s):  
Luteinizing Hormone ◽  
Female Rats ◽  
Gonadal Function ◽  
Prolonged Administration ◽  
Male And Female ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Male And Female Rats ◽  
Potent Antagonist

Differential effects of gonadal function on bone histomorphometry in male and female rats

2009 ◽  
Vol 4 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Russell T. Turner ◽  
Kathleen S. Hannon ◽  
Laurence M. Demers ◽  
James Buchanan ◽  
Norman H. Bell
Keyword(s):  
Bone Histomorphometry ◽  
Female Rats ◽  
Gonadal Function ◽  
Male And Female ◽  
Differential Effects ◽  
Male And Female Rats

Antagonists of LHRH with Histidine in the Priority Position 8

1993 ◽  
Vol 48 (6) ◽  
pp. 812-816 ◽  
Author(s):  
Anna Janecka ◽  
Si-Mei Shan ◽  
Cyril Bowers ◽  
Karl Folkers
Keyword(s):  
Luteinizing Hormone ◽  
Histamine Release ◽  
Side Effect ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Significant Release ◽  
Potent Antagonist ◽  
Antiovulatory Activity

Sixteen new designs of antagonists of the luteinizing hormone releasing hormone (LHRH) with histidine in position 8 were synthesized, because this position is critical both for antiovulatory activity and the side effect of histamine release. The most potent antagonist was NAcDQal-DpClPhe–D 3 Pal– Ser–cPzACAla–DPicLys– Leu– His – Pro –DAlaNH2, which showed 33% AOA at 0.25 μg. The histamine release was remarkably negligible by an ED50 of 308 μg/ml which is superior to 186 μg/ml for LHRH and comparable to 300 for Antide.The relative basicities of His, Arg, and ILys in position 8 of antagonists appear to influence both the level of potency of AOA and a negligible to a significant release of histamine. The least basic His8-analogs can have the lowest AOA and the highest ED50. The very basic Arg8-analogs can have the highest AOA and the lowest ED50. The moderately basic ILys8-analogs can be a compromise for acceptable levels of potency and safety.

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.

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