Total monoamine oxidase activity in the hypothalamus, ovary and uterus of rats with an extreme number of ovarian corpora lutea.

The activity of total monoamine oxidase (MAO) in the rat ovary and uterus fluctuates significantly under various physiological conditions. We analyzed total MAO activity in the hypothalamus, uterus and ovary in adult rats, having an extreme number of corpora lutea (hyperluteinized ovaries) resulting from the mechanical lesions in the posterior hypothalamic region of neonatal rats. Total MAO activity in the hypothalamus (30.21 +/- 1.53 pmol/mg tissue/min) and uterus (3.16 +/- 0.61 pmol/mg tissue/min) of rats with hyperluteinized ovaries did not show a significant difference as compared to that of intact controls (31.09 +/- 1.72 and 2.90 +/- 0.40 pmol/mg tissue/min, respectively). In contrast, in the ovaries of hyperluteinized rats, total MAO activity (21.16 +/- 1.70 pmol/mg tissue/min) was significantly higher (p<0.01) when compared to that of intact controls (13.61 +/- 1.30 pmol/mg tissue/min). The increased MAO activity in the hyperluteinized ovaries may be attributed to the increased number of transformed and accumulated corpora lutes as a consequence of diminished luteolysis.