Contrasting effects of pituitary adenylate cyclase activating polypeptide (PACAP) on in vivo and in vitro prolactin and growth hormone release in male rats

Life Sciences ◽  
1992 ◽  
Vol 51 (11) ◽  
pp. 823-830 ◽  
Author(s):  
H. Jarry ◽  
S. Leonhardt ◽  
W.E. Schmidt ◽  
W. Creutzfeldt ◽  
W. Wuttke
Keyword(s):  
Growth Hormone ◽  
Adenylate Cyclase ◽  
Male Rats ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Pituitary Adenylate Cyclase

The effect of d-fenfluramine on anterior pituitary hormone release in the rat: in vivo and in vitro studies

1987 ◽  
Vol 65 (12) ◽  
pp. 2449-2453 ◽  
Author(s):  
O. Serri ◽  
E. Rasio
Keyword(s):  
Growth Hormone ◽  
Male Rats ◽  
Serum Prolactin ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Serum Growth Hormone

Administration of d-fenfluramine, a serotonin-releasing drug, to male rats induced a dose-dependent increase in both serum prolactin and corticosterone concentrations. Serum growth hormone levels increased, but not significantly, at a dose of 1.25 mg/kg i.p. and decreased significantly at higher doses. When rats were pretreated with the serotonin uptake inhibitor fluoxetine (10 mg/kg i.p.) 30 min prior to injection of d-fenfluramine (5 mg/kg i.p.), the serum prolactin response to d-fenfluramine was partially inhibited, whereas the growth hormone response was not significantly modified. Fluoxetine pretreatment increased the serum corticosterone to the same level as did d-fenfluramine. d-Fenfluramine's effect on prolactin and growth hormone release was further tested in a hypothalamic–pituitary in vitro system. The addition of d-fenfluramine (5–500 ng/mL) for 30 min to rat hypothalami resulted in an enhancement of prolactin and growth hormone-releasing activities. These were expressed as the ability of the media in which the hypothalami had been incubated to stimulate prolactin and growth hormone release by cultured pituitary cells. The data suggest that the effect of d-fenfluramine on prolactin secretion is exerted through the hypothalamus and is probably mediated, at least partially, by a serotoninergic mechanism. The mechanism of d-fenfluramine's effect on corticosterone and growth hormone release needs further evaluation.

Pituitary adenylate cyclase-activating polypeptide (PACAP) 38 and PACAP27 differentially stimulate growth hormone release and mRNA accumulation in porcine somatotropes

Life Sciences ◽  
1998 ◽  
Vol 62 (26) ◽  
pp. 2379-2390 ◽  
Author(s):  
Antonio J. Martínez-Fuentes ◽  
María M. Malagón ◽  
Justo P. Castaño ◽  
JoséC. Garrido-Gracia ◽  
Francisco Gracia-Navarro
Keyword(s):  
Growth Hormone ◽  
Adenylate Cyclase ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Mrna Accumulation ◽  
Pituitary Adenylate Cyclase

Tri-iodothyronine inhibition of thyrotrophin-releasing hormone-induced growth hormone release from the chicken adenohypophysis in vitro

1990 ◽  
Vol 126 (1) ◽  
pp. 75-81 ◽  
Author(s):  
S. Harvey
Keyword(s):  
Growth Hormone ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Direct Effects ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Site Of Action

ABSTRACT Tri-iodothyronine (T3) had no effect on the basal level of GH release from chicken hemipituitary glands perifused in vitro. The GH response to TRH was, however, markedly suppressed following exposure to T3. Suppression of TRH-stimulated GH secretion was observed after a 2-h preincubation with T3, and was induced, in a dose-related way, by 0·01–10 μmol T3/l. Exposure to T3 also reduced the effectiveness of TRH, at concentrations of 0·001–10 μg/ml, to stimulate GH release. These results demonstrate that, in addition to a hypothalamic site of action, T3 is likely to suppress GH secretion in vivo by direct effects on pituitary GH release. Journal of Endocrinology (1990) 126, 75–81

Nitric Oxide Modulates in vivo and in vitro Growth Hormone Release in Acromegaly

1997 ◽  
Vol 66 (6) ◽  
pp. 426-431 ◽  
Author(s):  
Carla Micaela Cuttica ◽  
Massimo Giusti ◽  
Liliana Bocca ◽  
Paola Sessarego ◽  
Daniele De Martini ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Growth Hormone ◽  
In Vitro Growth ◽  
Hormone Release ◽  
Growth Hormone Release
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