The effect of prostaglandin E2 and prostaglandin F2 alpha on ovarian tissue in the Florida crayfish Procambarus paeninsulanus.

Prostaglandins are oxygenated fatty acid derivatives of arachidonic acid involved in a number of vertebrate and invertebrate reproductive processes. While the role of prostaglandins in vertebrate reproduction has been well established, their function in the invertebrate has not been investigated extensively. The purpose of this study was to investigate the effect prostaglandin E2 (PGE2) and prostaglandin F2 alpha (PGF2 alpha) on ovarian tissue in the crayfish Procambarus paeninsulanus. PGF2 alpha induced contraction of ovarian tissue in a dose-dependent manner, while PGE2 alpha had little effect. Incubation of ovarian tissue with PGF2 alpha also produced a dose-dependent increase in cAMP. In addition, the experimental technique of back-phosphorylation, in which exogenously added cAMP-dependent protein kinase is able to transfer phosphate to previously non-phosphorylated proteins, revealed that PGF2 alpha-induced increases in cAMP resulted in the specific phosphorylation of a 45 kDa protein. These data give evidence that PGF2 alpha may be involved in crustacean ovulation by causing the cAMP-mediated contraction of ovarian tissue and that this contraction may involve the phosphorylation of proteins associated with the cytoskeleton.