LONG-TERM INFLUENCE OF SIALOADENECTOMY ON REPRODUCTIVE-PERFORMANCE OFMALE-MICE

The influence of the submandibular gland, the major source of epitheli al growth factor, on male reproduction in mice was studied by removing the submandibular gland (sialoadenectomy) and examining its effects o n sperm production and copulation and fertility rates over an extended post-operation period. The removal of the submandibular gland caused a decrease in the number of epididymal spermatozoa 4 weeks after the o peration; the decrease became significant (P< 0.05) 6-10 weeks after t he operation compared with the sham operated and intact groups. There was no significant difference between prepuberal (30 days old) and pos tpuberal (60 days old) sialoadenectomy, indicating that the submandibu lar,oland is not related to the maturation of the seminiferous tubules . The reduction in the number of epididymal spermatozoa was due to the decrease in number of spermatogonia and spermatocytes per Sertoli cel l in the seminiferous tubules. When the reproductive performance was e xamined over 14 weeks, sialoadenectomized males showed a lower copulat ion rate and a significantly (P< 0.05) higher incidence of non-fertile copulation compared with the sham-operated and intact males. These re sults indicate that the submandibular gland and the secretion of epith elial growth factor from it affect spermatogenesis by acting on sperma togonial proliferation and sperm maturation.