Role of pituitary adenylate cyclase-activating peptide (PACAP) in the cyclic recruitment of immature follicles in the rat ovary.
Following the midcyclic gonadotropin surge, PACAP is transiently expressed for approximately 12 h in the cyclic adult rat ovary. PACAP is observed in granulosa/lutein cells of the large mature follicles destined to ovulate and is believed to be a regulator of acute progesterone production and luteinization in these follicles. PACAP is also observed in solitary theca cells of immature follicles and in interstitial glandular cells intimately surrounding immature follicles. To examine if PACAP could be involved in the process of cyclic recruitment of such immature follicles, we primed immature granulosa cells from prepubertal ovaries with PACAP (1 nM and 100 nM) for 12 h. The treatment significantly stimulated the subsequent 24 h FSH-induced estradiol production (2.2 and 2.4 fold, respectively). The response seemed to be caused by a stimulation of aromatase activity. Estradiol production induced by testosterone was increased 2.4 and 2.6 fold, respectively, whereas functional FSH-receptors (cAMP production following FSH stimulation) or spontaneous apoptosis (immunohistochemical detection of DNA fragments) was unaffected. We conclude that PACAP priming of immature rat granulosa cells for 12 h increases subsequent FSH induced estradiol production and that PACAP could be involved in the cyclic recruitment of immature follicles in the adult rat ovary.
Gräs
Søren
S
Department of Obstetrics and Gynecology, University of Copenhagen, Herlev Amtssygehus, DK-2730 Denmark. s.gras@dadlnet.dk
Høst
Erik
E
Fahrenkrug
Jan
J
D000818:Animals; D017209:Apoptosis; D001141:Aromatase / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000502:physiology; D009414:Nerve Growth Factors / Q000502:physiology*; D009479:Neuropeptides / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051381:Rats; D017208:Rats, Wistar
C495403:Adcyap1 protein, rat; D009414:Nerve Growth Factors; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP; D001141:Aromatase