PRESENCE OF PITUITARY ADENYLATE CYCLASE-ACTIVATING POLYPEPTIDE 38-IMMUNO-LIKE MATERIAL IN THE BRAIN AND OVARY OF THE FEMALE CRESTED NEWT, TRITURUS-CARNIFEX - ITS INVOLVEMENT IN THE OVARIAN SYNTHESIS OF PROSTAGLANDINS AND STEROIDS

The presence of pituitary adenylate cyclase-activating peptide (PACAP) 38-immune-like material (PACAP 38-IL) in the brain and ovary of the c rested newt, Triturus carnifex, and its action on ovarian steroidogene sis and prostaglandin synthesis were evaluated. The HPLC brain and ova ry extract peaks that eluted like PACAP 38 were considered PACAP 38-li ke material. The concentrations of PACAP 38-IL in the HPLC extracts we re measured by RIA. T. carnifex ovary was incubated with PACAP 38, bra in and ovary PACAP 38-IL, and inhibitors of cyclooxygenase (COX), aden ylate cyclase (AC) and phospholipase C (PLC) for 30 and 60 min. PACAP 38, and brain and ovary PACAP 38-IL increased prostaglandin E(2) (PGE( 2)) (30 and 60 min), and progesterone and corticosterone (60 min), but decreased oestradiol-17 beta (60 min). COX and PLC inhibitors counter acted the increases in PGE(2), progesterone and corticosterone and the decrease in oestradiol-17 beta, and the AC inhibitor also counteracte d them except for PGE(2). These results suggest that PACAP 38-IL, pres ent in T. carnifex brain and ovary, acts on PLC, inducing the increase of PGE(2) which, in turn, acting on AC, induces increases in progeste rone and corticosterone and a decrease in oestradiol-17 beta.