Saralasin-induced inhibition of ovulation in the in vitro perfused rat ovary is not replicated by the angiotensin II type-2 receptor antagonist PD123319.
OBJECTIVE
Our aim was to explain the effect of the nonspecific angiotensin II antagonist saralasin and the specific angiotensin II type-2 receptor antagonist PD123319 on ovulation.


METHODS
Saralasin, 1 micromol/L (n = 5), and PD123319 10 micromol/L (n = 6), were administered to in vitro perfused rat ovary. Prostaglandin (prostaglandin E2, prostaglandin F2alpha, 6-keto-prostaglandin F1alpha), hydroxy-eicosatetraenoic acid (12-hydroxy-eicosatetraenoic acid, 15-hydroxy-eicosatetraenoic acid), estradiol, and progesterone levels in the perfusate and the ovulation rate were compared (Mann-Whitney U test) with controls.


RESULTS
Saralasin significantly (P < .01) inhibited the ovulation rate (3.0 +/- 1.4) versus control (13.1 +/- 1.0) and reduced prostaglandin E2 (at 3 hours P < .01 and 20 hours P < .05) and 6-keto-prostaglandin F1alpha (at 20 hours P < .05) levels. Saralasin did not alter prostaglandin F2alpha, hydroxy-eicosatetraenoic acids, or steroid levels. PD123319 decreased 15-hydroxy-eicosatetraenoic acid levels at 3 hours (P < .05) but had no effects on other eicosanoids, steroid levels, or the ovulation rate.


CONCLUSIONS
Angiotensin II plays an important role in ovulation in the rat and is associated with ovarian prostaglandin synthesis. This effect is not selectively regulated via the angiotensin II type-2 receptor.
Mikuni
M
M
Department of Obstetrics and Gynecology, Göteborg University, Sweden.
Brännström
M
M
Hellberg
P
P
Peterson
C A
CA
Pall
M
M
Edwin
S S
SS
Peterson
C M
CM
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D005260:Female; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D008084:Lipoxygenase / Q000378:metabolism; D010053:Ovary / Q000187:drug effects*; D010060:Ovulation / Q000187:drug effects*; D010477:Perfusion; D011453:Prostaglandins / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012504:Saralasin / Q000494:pharmacology*; D012636:Secretory Rate / Q000187:drug effects; D018709:Statistics, Nonparametric; D013256:Steroids / Q000096:biosynthesis
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D007093:Imidazoles; D011453:Prostaglandins; D011725:Pyridines; D013256:Steroids; C073402:PD 123319; D008084:Lipoxygenase; D012504:Saralasin