Effects of age and gender on the AII-induced stimulation of prolactin release and inositol phosphate accumulation in rat anterior pituitary cells in vitro.
The stimulatory effects of Angiotensin II (AII) on prolactin secretion and inositol phosphate accumulation were examined in dispersed anterior pituitary cells collected from young (3-4 month), mature (7-8 month) and old (18-20 month) male and female rats. Physiological doses of AII (0.01-10 nM) stimulated prolactin release from cells collected from mature female rats only. This effect was antagonized by pretreatment with Saralasin, an AII receptor antagonist. Significant accumulation of the inositol phosphates was observed in cells obtained from the mature, female donors and this increase preceded the prolactin response. Although there was a small increase in total inositol phosphate accumulation in cells obtained from the old female rats, this was transient and did not coincide with a similar increase in prolactin release. These results indicate that pituitary sensitivity to AII stimulation is related to the age and the gender of the donor animal. The physiological role of pituitary AII needs to be examined in sexually mature female animals.
Janik
J M
JM
Department of Zoology, Miami University, Oxford, OH 45056, USA.
Robinson
E O
EO
Shen
J
J
Callahan
P
P
D000375:Aging / Q000502:physiology*; D000804:Angiotensin II / Q000494:pharmacology*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D005260:Female; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000502:physiology*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012504:Saralasin / Q000494:pharmacology; D012727:Sex Characteristics
D057911:Angiotensin Receptor Antagonists; D007295:Inositol Phosphates; D000804:Angiotensin II; D011388:Prolactin; D012504:Saralasin