[Features of endocrine function of the pancreas with aging in nonhuman primates with various types of adaptive behavior.]

An increasing number of studies are devoted to the study of the relationship of mental disorders, such as depression and anxiety, with the risk of developing type 2 diabetes mellitus. However, in the literature there are practically no publications on the study of the relationship of the features of higher nervous activity, in particular, adaptive behavior, in healthy individuals with the risk of developing age-related dysfunction of the pancreatic islet apparatus (PIA). The purpose of this study was to investigate features of the functioning of the PIA during aging in individuals with normal standard behavior (SB), as well as anxiety- and depressive-like behavior (DAB) in experiments on nonhuman primates. 76 physically healthy young mature and old female rhesus monkeys with SB and DAB were used in the experiments. Old animals were divided into subgroups with normal (NW) and excess (EW) body weight. All young animals were characterized by NW. The function of PIA was assessed using a glucose tolerance test. Intergroup differences in the functioning of the PIA in young animals were revealed, which were characterized by signs of impaired early insulin response, apparently due to a decrease in the sensitivity of β-cells of the pancreas to glucose. With aging, the function of the PIA was damaged in all animals, but the features of its changes depended on both the affiliation to a particular behavioral group and the animal's body weight. During aging in animals with SB, the development of relative insulin resistance of peripheral tissues was observed, accompanied by impaired glucose tolerance and a compensatory increase in the secretory activity of the PIA, which were more pronounced in animals with EW. Age-related dysfunction of the PIA in animals with DAB and NW was similar with age-related changes in the PIA function in animals with SB and NW. At the same time, with aging, animals with DAB and EW showed a more significant peak concentration of glucose than that of old animals with SB and EW, accompanied by a minimum «disappearance» rate of glucose from the circulation and significantly lower insulin secretion than this in animals with SB and EW. Thus, age-related dysfunctions of the PIA in primates with SB and DAB are unidirectional with the development of insulin resistance, impaired glucose tolerance and a compensatory increase in insulin secretion, which, however, in old animals with DAB and EW are accompanied by exhaustion of the PIA function, increasing the risk of developing type 2 diabetes mellitus.