Prostaglandin E2 in previtellogenic ovaries of the prawn Macrobrachium rosenbergii: synthesis and effect on the level of cAMP.
Eicosanoids are thought to play a role in the regulation of invertebrate reproduction, as they do in vertebrate systems. This was investigated using the previtellogenic ovary of the freshwater prawn Macrobrachium rosenbergii as a biological model. Concentrations of prostaglandin E2 (PGE2), assessed by means of radioimmunoassay, in the previtellogenic ovary (oocyte diameter 20-40 microns) were 32.4 +/- 14.1 pg/mg ovary. Preincubation of the ovary with indomethacin (10 microM) inhibited PGE2 synthesis by 43%. In addition, if indomethacin was added to the culture medium, cAMP levels decreased by 48%. When previtellogenic ovaries were incubated in vitro with PGE2 (0.05 micrograms/ml medium and up), cAMP levels in the tissue homogenate sharply increased. The levels of cAMP rose most significantly (up to 10-fold) when 1-10 micrograms PGE2/ml medium was applied. These results suggest that PGE2, and possibly other prostaglandins, may play a role in the endocrine regulation of crustacean reproduction.
Sagi
A
A
Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Silkovsky
J
J
Fleisher-Berkovich
S
S
Danon
A
A
Chayoth
R
R
D000704:Analysis of Variance; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D015232:Dinoprostone / Q000096:biosynthesis*; D005260:Female; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D033541:Palaemonidae; D011863:Radioimmunoassay
D016861:Cyclooxygenase Inhibitors; D000242:Cyclic AMP; D015232:Dinoprostone; D007213:Indomethacin