Pregnenolone sulfate modulates angiotensin II-induced inositol 1,4,5-trisphosphate changes in the anterior pituitary of female rat.
The present study was designed to test whether pregnenolone sulfate can influence the angiotensin II (AngII) action in the anterior pituitary. Female rats were ovariectomized and 10 days after operation were treated with either 50 or 250 microg per animal in one of the following substances: oil (control), pregnenolone sulfate (PREG-S), estradiol benzoate (E(2),) progesterone (P), or dehydroepiandrosterone sulfate (DHEA-S), given in single intraperitoneal injection. Because AngII is known to act in the anterior pituitary through the phosphatidiloinositol breakdown, thus increasing the level of inositol-1,4,5-trisphosphate (IP(3)), the IP(3) concentration was determined 24 h after the injection in the anterior pituitary homogenate after in vitro exposure to AngII. Among the tested steroids only PREG-S enhanced the basal (without AngII) and AngII-induced level of IP(3) in both doses used. There was no difference between the effect of a high and low dose of PREG-S. These results show that PREG-S may modulate AngII action in the anterior pituitary, regardless of the presence of ovary.
Lachowicz
A
A
Institute of Endocrinology, Department of Experimental Endocrinology and Hormone Research, Medical University of Lódz, Dr. Sterling Street 3, Lódz, 91-425, Poland. alo@mail.e.pl
Pawlikowski
M
M
Rebas
E
E
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D003687:Dehydroepiandrosterone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D010053:Ovary / Q000502:physiology; D010902:Pituitary Gland / Q000201:enzymology*; D011284:Pregnenolone / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology; D051381:Rats
D000276:Adjuvants, Immunologic; C018370:pregnenolone sulfate; D000804:Angiotensin II; C074283:estradiol 3-benzoate; D003687:Dehydroepiandrosterone; D011374:Progesterone; D004958:Estradiol; D011284:Pregnenolone; D015544:Inositol 1,4,5-Trisphosphate