| Abstract: | As has been reported earlier, submandibular glands of animals and man contain insulin-like protein (ILP), similar in some of its properties to pancreatic insulin. An immunocytochemical method with polyclonal anti-insulin serum has shown that ILP is contained in cells of the submandibular gland granular ducts. This paper is concerned with the determination of localization of ILP and estimation of its structural identity with insulin by using monoclonal antibodies to pig insulin. ILP and insulin were extracted from mouse submandibular glands and pancreas and partially purified. Solid-phase immunoenzymatic analysis was used to determine the capacity of mouse ILP and pancreatic insulin to bind specifically with monoclonal antibodies to pig insulin indicating the structural identity of ILP and insulin. The absence of cross-reaction of antibodies with the nerve growth factor and kallikrein (biologically active substances contained in the submandibular gland granular ducts) was established. An immunofluorescent indirect method with the use of monoclonal antibodies to insulin has shown that ILP is localized in cells of the submandibular gland granular ducts. It confirms the previously reported results. |
