Stimulation of cyclic AMP accumulation in the rat anterior pituitary in vitro by analogs of luteinizing hormone-releasing hormone

1975 ◽  
Vol 31 (4) ◽  
pp. 403-404
Author(s):  
W. Lippmann
Keyword(s):  
Luteinizing Hormone ◽  
Cyclic Amp ◽  
Anterior Pituitary ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Cyclic Amp Accumulation ◽  
Stimulation Of

STIMULATION OF PROSTAGLANDIN ACCUMULATION IN THE RAT ANTERIOR PITUITARY GLAND BY LUTEINIZING HORMONE RELEASING HORMONE IN VITRO

1977 ◽  
Vol 75 (2) ◽  
pp. 277-283 ◽  
Author(s):  
N. BARDEN ◽  
A. BETTERIDGE
Keyword(s):  
Luteinizing Hormone ◽  
Cyclic Amp ◽  
Anterior Pituitary ◽  
Pituitary Cells ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Release ◽  
Lh Rh ◽  
Stimulation Of

The addition of luteinizing hormone releasing hormone (LH-RH) to cultures of monolayers of rat anterior pituitary cells was shown to increase both the concentrations of prostaglandins E1 and E2 (PGE) in the cells and the release of LH over similar ranges of concentrations of LH-RH (10−6 to 10−10 mol/l). The peak concentration of PGE was observed after 2·5 h. The stimulation of the level of PGE in the cells by LH-RH was completely inhibited by two inhibitors of prostaglandin synthetase, which only partially inhibited the stimulation of LH release. Therefore the increased concentration of PGE was not obligatory for the effect of LH-RH on LH release. It was also shown that monobutyryl cyclic AMP stimulated the intracellular concentration of PGE and it is suggested that the stimulation of PGE levels may be mediated by increased levels of cyclic AMP in the cells after the addition of LH-RH.

RELATIVE ACTIVITY, PLASMA ELIMINATION AND TISSUE DEGRADATION OF SYNTHETIC LUTEINIZING HORMONE RELEASING HORMONE AND CERTAIN OF ITS ANALOGUES

1979 ◽  
Vol 80 (1) ◽  
pp. 141-152 ◽  
Author(s):  
A. D. SWIFT ◽  
D. B. CRIGHTON
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Inverse Correlation ◽  
Anterior Pituitary Gland ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Rh

The abilities of three nonapeptide analogues of synthetic luteinizing hormone releasing hormone (LH-RH) to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in anoestrous and cyclic ewes were examined, as were their elimination from the plasma in vivo and degradation by extracts of the hypothalamus, anterior pituitary gland, lung, kidney, liver and plasma in vitro. In all cases, comparisons were made with synthetic LH-RH. When injected i.v. into mature ewes as a single dose, the potencies of the analogues were graded and Des Gly-NH210 LH-RH ethylamide was found to be the least potent. It was not possible to demonstrate any significant increase in the potency of this analogue over LH-RH, although a trend was apparent with each parameter examined. [d-Ser(But)6] Des Gly-NH210 LH-RH ethylamide had the greatest potency. There were no differences between the responses of anoestrous ewes and those of ewes treated on day 10 of the oestrous cycle. None of the analogues had a rate of elimination from the plasma different from that of LH-RH during either the first or the second components of the biphasic disappearance curve. The incubation of LH-RH with tissue extracts showed that extracts of the hypothalamus and anterior pituitary gland degraded LH-RH to a similar extent. Both the hypothalamic and anterior pituitary gland extracts degraded more LH-RH than did lung extract, which in turn destroyed more LH-RH than did extracts of kidney or liver tissue. The degradative abilities of kidney and liver extracts did not differ from each other. Plasma failed to degrade LH-RH or the analogues. Although LH-RH was rapidly destroyed by hypothalamic extract in vitro, of the analogues, only Des Gly-NH210 LH-RH ethylamide was degraded. The anterior pituitary gland and kidney extracts failed to degrade [d-Ser6] Des Gly-NH210 LH-RH ethylamide and [d-Ser(But)6] Des Gly-NH210 LH-RH ethylamide as rapidly as LH-RH. Extracts of liver and lung were incapable of catabolizing any of the analogues. There was an inverse correlation between the LH- and FSH-releasing potency of an analogue and its rate of degradation by anterior pituitary gland extract. The slower rates of catabolism of certain analogues of LH-RH by the anterior pituitary gland may explain their increased LH- and FSH-releasing potency.

EFFECT OF LUTEINIZING HORMONE RELEASING HORMONE ON ACCUMULATION OF PITUITARY CYCLIC AMP AND GMP IN VITRO

1978 ◽  
Vol 76 (2) ◽  
pp. 367-368 ◽  
Author(s):  
G. L. RIGLER ◽  
G. T. PEAKE ◽  
A. RATNER
Keyword(s):  
New Mexico ◽  
Luteinizing Hormone ◽  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
University Of New Mexico ◽  
Cellular Events ◽  
Lh Rh

Departments of Physiology and Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, U.S.A. (Received 19 August 1977) Cyclic AMP has been increasingly implicated as an important intracellular mediator regulating the secretion of peptide hormones (Vale, Grant & Guillemin, 1973), but there is controversy concerning its role in the regulation of the luteinizing hormone releasing hormone (LH-RH)-stimulated secretion of luteinizing hormone (LH; Labrie, Pelletier, Borgeat, Drouin, Ferland & Belanger, 1976; Ratner, Wilson, Srivastava & Peake, 1976; Sundberg, Fawcett & McCann, 1976). Although less clearly established, the guanyl cyclase–cyclic GMP system may also play an important role in regulating cellular events (Goldberg, O'Dea & Haddox, 1973). Studies with a highly purified growth hormone (GH) releasing factor suggested the involvement of cyclic GMP in the mediation of GH release from the somatotrope (Wilson, Steiner, Dhariwal & Peake, 1974). This communication describes studies which suggest a role for the guanylate

Stimulation of Prostaglandin Accumulation by Luteinizing Hormone-Releasing Hormone (LHRH) and LHRH Analogs in Rat Granulosa Cells in Vitro*

Endocrinology ◽  
1980 ◽  
Vol 107 (1) ◽  
pp. 17-23 ◽  
Author(s):  
MARTIN R. CLARK ◽  
CATHERINE THIBIER ◽  
JOHN M. MARSH ◽  
WILLIAM J. LEMAIRE
Keyword(s):  
Luteinizing Hormone ◽  
Granulosa Cells ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Stimulation Of
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