Long-term estrogenization in mammals. I. Histopathology of kidney, bladder, adrenals, and gonads; polydipsia; body weight; and serum levels of corticosterone and testosterone in estrogenized Marsh mice.

Single, sublethal, long-acting doses of estrone or estradiol cypionate produced the following histologic, behavioral, and blood chemistry effects in Marsh mice: (a) Bladder pathology developed following estrogen-induced polydipsia but was not consistently associated with kidney damage. (b) This polydipsia was more intense (a maximum of 250% over control intake) when the housing was in metal cages with floor screens than in plastic cages with bedding. Water intake of control mice was unaffected by housing changes. (c) Comparing litter-mate 2.5-month-old males and females, body weight loss following estrogen administration was transient with the females. With males, initial weight losses as compared with weight gains in the controls were demonstrated over a 20-week period. (d) Estrogenization markedly increased corticosterone and decreased testosterone serum levels with a significant negative correlation for these levels in the estrogenized mice. A significant positive correlation was also observed between testosterone levels and testis weights in the estrogenized mice.