Rat Corpus Luteum Expresses Both PACAP and PACAP Type IA Receptor MRNAs

Both pituitary adenylate cyclase-activating polypeptide (PACAP) and PACAP type I receptor gene expressions were detected in the corpus luteum of pregnant mare's serum gonadotropin (PMSG)-human chorionic gonadotropin (hCG)-treated immature rats using reverse transcription-polymerase chain reaction (RT-PCR). RT-PCR products of the poly(A)+ RNA extracted from rat corpora lutea yielded dominant DNA bands that corresponded to segments of PACAP mRNA (453 bp) and PACAP type IA receptor mRNA (290 bp) spanned by the PCR primers. The identities of the PACAP cDNA and the PACAP receptor cDNA fragments were confirmed by Southern blot hybridization analyses. Our results showed that PACAP mRNA and PACAP type IA receptor mRNA are synthesized within luteinized cells of rat ovary, and suggest that PACAP is closely linked to the reproductive process.