THE RABBIT SUBMANDIBULAR-GLAND - SEXUAL DIMORPHISM, EFFECTS OF GONADECTOMY, AND VARIATIONS ACROSS THE FEMALE REPRODUCTIVE-CYCLE

Sex differences and the effect of various endocrine conditions on the histology of the rabbit (Oryctolagus cuniculus L.) submandibular (chin ) gland were investigated. The female gland contained significantly mo re acini/field than the male gland. The diameter of acini was signific antly smaller than those of the male gland. Gonadectomy reduced the nu mber of acini/field and increased their diameter in females but provok ed the opposite effect in males. Gonadectomy drastically reduced the p ercent of acini with crystal bodies in both sexes, and the percent of acini with apocrine secretion only in females. Estrous does showed a s ignificantly higher number of acini/field than pregnant (days 20 and 2 9) and lactating (day 6) does. Acini containing crystal bodies decline d from 22% in estrous females to 8% and 3% in pre-parturient (gestatio n day 31) and lactating (day 6) does, respectively. By contrast, acini showing apocrine secretion increased from 12% in estrous females to 4 3% in pre-parturient does and declined to 23% on lactation day 6. In a ll glands glycoproteins were noted in crystal bodies but not in apocri ne secretion. Results show a sexual dimorphism in the rabbit chin glan d histology and support the participation of gonadal steroids in its p hysiological regulation.