Immunocytochemical detection of estrogen and progesterone receptors in therabbit submandibular gland

Rabbit submandibular glands produce secretions invoked in olfactory communi cation. The histology of these glands and their secretory activity are: sex ually dimorphic; vary across the female reproductive cycle; and are modifie d by gonadectomy. This suggests that gonadal steroids regulate the structur e and function of such glands. To further support this idea we assessed by immunocytochemistry the presence of estrogen and progesterone receptors in male and female rabbit submandibular glands. Immunoreactivity was detected only in the nucleus of acini cells. The number of estrogen receptor-immunor eactive cells/field varied among estrus (26 +/- 6; mean +/- S.E.), ovariect omized (19 +/- 2), and ovariectomized-estrogen-treated animals (13 +/- 3). Intact males showed a significantly smaller number of estrogen receptor-imm unoreactive cells/field (12+/-1) than estrous females. Interestingly, proge sterone receptor-immunoreactive cells mere more abundant in estrous (32 +/- 7) than in ovariectomized animals (7 +/- 1). Estradiol benzoate (5 mu g da ily for 5 days) increased the number of progesterone receptor-immunoreactiv e cells/field in ovariectomized females (17 +/- 1). Intact males showed few er progesterone receptor-immunoreactive cells/field (16 +/- 2) than estrous females. Results show that the rabbit submandibular gland is a target for estrogen and progesterone and support the idea that these hormones particip ate in regulating the physiology of this gland. (C) 1999 Elsevier Science I nc. All rights reserved.