title: Possible mechanism for the first response to short captivity stress in the water frog, Rana esculenta.
abstract: To clarify the endocrine mechanism involved in the short captivity stress in the water frog, Rana esculenta, the activity of 9-ketoreductase, the enzyme which converts prostaglandin E2 (PGE2) into prostaglandin F2 alpha (PGF2 alpha), and aromatase, which converts testosterone into oestradiol-17 beta, were studied. Adult male and female frogs were sacrificed 0, 1.5, 3, 6, 12, 24, 48, 72, 168 and 336 h after capture in the field. PGE2, PGF2 alpha, progesterone, testosterone, oestradiol-17 beta and corticosterone plasma levels were detected by RIA at each time point. 9-Ketoreductase (conversion of [3H]PGE2 into [3H]PGF2 alpha) and aromatase (conversion of [3H]testosterone into [3H]oestradiol-17 beta) activities in the brain, testis, ovary and interrenal were also determined at each time point. After capture, levels of plasma PGF2 alpha increased (male: 228%; female: 288%) and PGE2 decreased (male: 68%; female: 81%) at 1.5 h, oestradiol-17 beta increased (male: 399%; female: 425%) and testosterone decreased (male: 87%; female: 83%) at 6 h, and corticosterone increased (male: 421%; female: 426%) at 72 h. 9-Ketoreductase activity in the brain was enhanced at 1.5 h after capture (male: 249%; female: 262%); aromatase activity increased at 6 h in the testis (261%), ovary (273%) and interrenal (male: 227%; female: 267%). These results indicate that short captivity stress could induce an increase in plasma PGF2 alpha through activation of brain 9-ketoreductase. In turn, PGF2 alpha might enhance the levels of circulating oestradiol-17 beta through activation of gonadal and interrenal aromatase.
authors.affiliation: Department of Molecular, Cellular and Animal Biology, University of Camerino, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gobbetti
authors.forename: M
authors.initials: M
authors.lastname: Zerani
mesh_terms: D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D001921:Brain / Q000201:enzymology*; D003345:Corticosterone / Q000097:blood; D015237:Dinoprost / Q000097:blood; D015232:Dinoprostone / Q000097:blood; D004789:Enzyme Activation; D004958:Estradiol / Q000097:blood; D005260:Female; D006911:Hydroxyprostaglandin Dehydrogenases / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology; D008297:Male; D008954:Models, Biological; D010053:Ovary / Q000201:enzymology; D011374:Progesterone / Q000097:blood; D011893:Rana esculenta / Q000502:physiology*; D012149:Restraint, Physical; D012737:Sex Factors; D013315:Stress, Psychological / Q000378:metabolism*; D013737:Testis / Q000201:enzymology; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D015237:Dinoprost; D006911:Hydroxyprostaglandin Dehydrogenases; C035858:prostaglandin-E2 9-reductase; D001141:Aromatase; D015232:Dinoprostone; D003345:Corticosterone