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Hormonal and Cellular Brain Mechanisms Regulating the Amplexus of Male and Female Water Frog ( Rana esculenta )
Author(s) -
Anna Gobbetti,
Massimo Zerani
Publication year - 1999
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1046/j.1365-2826.1999.00369.x
Subject(s) - aromatase , medicine , endocrinology , testosterone (patch) , biology , aromatase inhibitor , nitric oxide synthase , nitric oxide , cancer , breast cancer
The role of nitric oxide (NO) synthase, prostaglandin E 2 –9‐ketoreductase, and aromatase brain activities in regulating frog amplexus was assessed in the water frog ( Rana esculenta ). Plasma concentrations of testosterone were higher, and concentrations of 17 β ‐oestradiol lower, in amplexing males than in unamplexing males; while concentrations of testosterone and PGE 2 were lower, and those of 17 β ‐oestradiol and PG F 2 α higher, in amplexing females compared to unamplexing females. Hormone release rescued from frog brains in vitro mirrored plasma hormone measures. Brain aromatase activity was lower in amplexing males; NO synthase was lower and PGE 2 –9‐ketoreductase and aromatase were higher in amplexing females. In male brains, PGE 2 –9‐ketoreductase inhibitor decreased PG F 2 α release and increased that of PGE 2 ; aromatase inhibitor decreased 17 β ‐oestradiol and increased testosterone release. In female brains, NO donor and PGE 2 –9‐ketoreductase inhibitor increased testosterone and PGE 2 release and decreased that of 17 β ‐oestradiol and PG F 2 α ; NO synthase inhibitor decreased testosterone release and PGE 2 and increased 17 β ‐oestradiol and PG F 2 α release; PG F 2 α decreased testosterone release and increased 17 β ‐oestradiol release; aromatase inhibitor decreased 17 β ‐oestradiol release and increased testosterone release. In female brains, NO donor and PGE 2 –9‐ketoreductase inhibitor decreased PGE 2 –9‐ketoreductase and aromatase activities; PG F 2 α increased aromatase activity; NO synthase inhibitor increased PGE 2 –9‐ketoreductase and aromatase activity. The data suggest that, in amplexing female brains, external and/or internal stimuli inhibit NO synthase, decreasing NO and activating PGE 2 –9‐ketoreductase; in turn, PG F 2 α increases aromatase activity and 17 β ‐oestradiol release; while, in amplexing male brains, stimuli inhibit aromatase activity, thereby increasing testosterone production.