Vagotomy and Splenectomy Reduce Insulin Secretion and Interleukin-1β

Abstract

Objectives: This study aimed to evaluate the effect of vagotomy, when associated with splenectomy, on adiposity and glucose homeostasis in Wistar rats.Methods: Rats were divided into 4 groups: vagotomized (VAG), splenectomized (SPL), VAG + SPL, and SHAM. Glucose tolerance tests were performed, and physical and biochemical parameters evaluated. Glucose-induced insulin secretion and protein expression (Glut2/glucokinase) were measured in isolated pancreatic islets. Pancreases were submitted to histological and immunohistochemical analyses, and vagus nerve neural activity was recorded. Results:The vagotomized group presented with reduced body weight, growth, and adiposity; high food intake; reduced plasma glucose and triglyceride levels; and insulin resistance. The association of SPL with the VAG surgery attenuated, or abolished, the effects of VAG and reduced glucose-induced insulin secretion and interleukin-1β area in β cells, in addition to lowering vagal activity. Conclusions:The absence of the spleen attenuated or blocked the effects of VAG on adiposity, triglycerides and glucose homeostasis, suggesting a synergistic effect of both on metabolism. The vagus nerve and spleen modulate the presence of interleukin-1β in β cells, possibly because of the reduction of glucose-induced insulin secretion, indicating a bidirectional flow between autonomous neural firing and the spleen, with repercussions for the endocrine pancreas.

Phenylhydrazine‐induced anaemia reduces subcutaneous white and brown adipose tissues in hypothalamic obese rats

“…Autonomic imbalance is an important element of adiposity in this obesity model (Miranda et al, 2016;Yoshida et al, 1985). It has been shown that vagal hyperactivity promotes hyperinsulinaemia and favours adipogenesis in MSG-obese rats (Kuchler et al, 2021;Miranda et al, 2016;Siqueira et al, 2021).…”

“…Autonomic imbalance is an important element of adiposity in this obesity model (Miranda et al., 2016; Yoshida et al., 1985). It has been shown that vagal hyperactivity promotes hyperinsulinaemia and favours adipogenesis in MSG‐obese rats (Kuchler et al., 2021; Miranda et al., 2016; Siqueira et al., 2021). Moreover, reduced sympathetic activity leads to a lesser lipolytic effect on WAT and a reduction in thermogenic responsiveness of BAT in MSG‐obese rodents (Yoshida et al., 1985).…”