AGE-DEPENDENT CHANGES IN INSULIN-LIKE IMMUNOREACTIVITY IN RAT SUBMANDIBULAR SALIVARY-GLANDS

In recent years, a growing interest had arisen in hormonal factors in salivary glands. We have investigated the changes in the content of an insulin-like immunoreactive (ILI) compound in the submandibular saliv ary glands of Sprague Dawley rats during physiological aging, in the r ange 15 days -27 months. The amount of ILI in the submandibular glands of young. adult rats was found to be doubled in the post-natal period until the age of puberty and was maintained in senescence, No signifi cant correlation was found between age-dependent variations in ILI lev els of submandibular salivary glands and circulating insulin concentra tions, further supporting previous indications that ILI is being synth esized in situ. It is possible that ILI could exert paracrine effects within the glands, as regards the development of other glandular struc tures during the first months of life, as well as the preservation of glandular function in senescent animals as well.