Urinary excretion of histamine, in the rat, in relation to sex

Abstract
The excretion of free histamine in adult rats previously hydrated was studied in the following groups of animals: 1) normal males; 2) normal females; 3-5) ovariectomized, tested after 7, 40 and 120 days; 6-7) sham operated females, tested after 7 and 120 days; 8) ovariectomized testosterone-treated, and 9) sham operated testosterone-treated females.
No changes in the rate of histamine excretion were observed after seven days in ovariectomized and sham operated rats; but the urinary histamine was depressed in ovariectomized rats after 40 days from the operation. Testosterone propionate (0,5 mg/day during 5 days) significantly reduced the urinary excretion of free histamine in castrated and sham operated female rats, and the reduction was largest for the castrated animals; but in no case the urinary excretion of histamine was depressed to the male level.