In Vitro Release of Gonadotropins from the Pituitary of Cocks by an Analogue of Luteinizing Hormone-Releasing Hormone: [Des-Gly-NH210, Pro-ethylamide9]-LH-RH

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.

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Effects of Neuropeptide Y on the in vitro Release of Gonadotropin-Releasing Hormone, Luteinizing Hormone, and Beta-Endorphin and Pituitary Responsiveness to Gonadotropin-Releasing Hormone in Female Macaques

Neuroendocrinology ◽

10.1159/000125747 ◽

1991 ◽

Vol 53 (4) ◽

pp. 396-403 ◽

Cited By ~ 18

Author(s):

K.-Y. Francis Pau ◽

Alan H. Kaynard ◽

David L. Hess ◽

Harold G. Spies

Keyword(s):

Luteinizing Hormone ◽

Neuropeptide Y ◽

In Vitro Release ◽

Gonadotropin Releasing Hormone ◽

Releasing Hormone ◽

Beta Endorphin ◽

Vitro Release

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APPLICATION OF AN IN-VITRO PERIFUSION TECHNIQUE TO STUDIES OF LUTEINIZING HORMONE RELEASE BY RAT ANTERIOR HEMI-PITUITARIES: SELF-POTENTIATION BY LUTEINIZING HORMONE RELEASING HORMONE

Journal of Endocrinology ◽

10.1677/joe.0.0680197 ◽

1976 ◽

Vol 68 (2) ◽

pp. 197-207 ◽

Cited By ~ 29

Author(s):

J. A. EDWARDSON ◽

D. GILBERT

Keyword(s):

Luteinizing Hormone ◽

Priming Effect ◽

Hormone Release ◽

Physiological Control ◽

Luteinizing Hormone Releasing Hormone ◽

Releasing Hormone ◽

Hypothalamic Extract ◽

Lh Rh ◽

Lh Secretion

SUMMARY A technique is described for the continuous perifusion of rat adenohypophyses. Exposure of the perifused glands to repeated equal 5 min stimuli with hypothalamic extract resulted in a series of equal peaks of corticotrophin secretion, the response was proportional to log dose over the range 0·25–2·0 rat hypothalamic equivalents/ml. Repeated equal stimuli with hypothalamic extract, or with luteinizing hormone releasing hormone (LH-RH) at concentrations of 2 or 10 ng/ml, resulted in a progressively increasing series of peaks of LH secretion, i.e. a self-potentiating or priming effect. The effect took between 30 min and 1 h to develop. A delayed increase in the responsiveness of the glands was also seen with continuous incubation of anterior pituitaries with LH-RH. The relevance of these observations to the physiological control of LH secretion is discussed.

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