Sialoglycoconjugate dimorphism of the mouse submandibular gland acinar cells. Ultrastructural evidence by lectin-protein A-gold probes and sialidase digestion

Abstract

An ultrastructural analysis of lectin receptors on th e submandibular glands fro m mice of both sexes was performed utilizing horseradish pero xidase-labell ed lectins in conjunction with antiperox idase antibody and protein A-gold . Both qu alitati ve and quantit ati ve sexrelated differe nces in terminal suga r expression within secre tory gran ul es were detected. Following sia lidase digestion. also suhtenninal acceptor suga rs for terminal siali c ac ids, proved to be differentiall y ex pressed in the submandibular g land s of mal es and fema le s. Heteroge neo us distributi on of sialoglycoconjugates characteri zed bv the terminal disaccharide sialic acid-/3- galactose was f~ llIndt o occur in female ac inar ce lls. Also DBA reacti ve sites indicating the presence of terminal CI.-N-ace tylgalactosamin e discriminated betwee n male and female ac in ar sec re tor y glycoco nju ga tes. This difference was emphasized by sialidase pretreatment that ev idenced a marked occurrence of sialic acid subtended to u- N-ace tvlga lac tosamine in males in contrast to a modest pr es-e ~ce in fe males. The different sial ylation pa tt e rn s of acinar cell sec reto ry prod uc ts, pro bab ly related to a different exp ressio n of 0- and N-linked sia logl ycoconjugates, g iv e in sig ht into th e sex ual dimorphism of the mouse submandibular gland known until rece ntl y for the convoluted granular tubules.