Mast cell histamine and ovarian follicular growth in the lizard Anolis carolinensis.

The hypothesis is proposed that histamine released from mast cells in the theca of ovarian follicles increases thecal hyperemia and vessel permeability, and thus plays a role in follicular growth in Anolis carolinensis. Mast cells are present in the stroma and theca, and the number of thecal mast cells increases as follicles grow. The levels of histamine in follicular walls varies with follicular size. Histamine causes vasodilatation of thecal vessels. Antihistamine blocks the effects of histamine and, when given alone, stimulates vasoconstriction. Antihistamine also blocks estradiol-induced growth of large follicles. These findings are consistent with the above hypothesis.