Influência da vagotomia e/ou esplenectomia sobre a estrutura morfológica renal em ratos obesos-MSG

Abstract

Chronic kidney disease (CKD) is one of the most important public health problems worldwide, and its main implications involve damage to nephron structures and loss of kidney function. Studies show that obesity is an independent risk factor for CKD. Obesity causes several structural, hemodynamic and metabolic changes in the kidney. Most of these changes can be compensatory responses to the systemic increase in metabolic demand observed in obesity. However, in some cases, kidney damage becomes clinically affected as a result of compensatory failure. Obesityrelated glomerulopathy (GRO) is the best known. The aim of the work was to evaluate the relation of autonomic vagal and splenic activities on renal histomorphometric aspects in MSG-obese rodents. Thirty male Wistar rats were used, of which, twenty-four received subcutaneous injections of monosodium glutamate (MSG group) during the first 5 days of life (4g/kg body weight) and six animals received subcutaneous injections of equimolar saline solution (control group). They were assigned to five experimental groups (n = 6/group): False operated control (CON-FO); false operated obese (MSG-FO); vagotomized obese (MSG-VAG); splenectomized obese (MSG-ESP); vagotomized and splenectomized obese (MSG-VAG-ESP). At 150 days, the animals were weighed and euthanized. The kidney was removed, weighed and subjected to histological techniques for fixation, dehydration and embedding. Sections were stained with HE and subjected to histomorphometric analysis. MSG-FO group animals showed a significant reduction in body weight and snout-anus length, and a significant increase in obesity parameters when compared to CON-FO group animals (P<0.05). Vagotomy and splenectomy surgeries, either alone or in combination, significantly reduced most of the biometric parameters associated with obesity. The kidneys of MSG-FO group animals showed altered histological structure, associated with a significant reduction in renal weight and diameters of glomerular tuft area, capsule area and the Bowman space when compared to CON-FO group animals (P<0.05). In the analysis of renal parameters of the MSG-VAG, MSG-ESP, MSG-VAG-ESP groups, there was a significant reduction in diameter, glomerular tuft area, capsule area, Bowman's space area when compared to the MSG-FO group, mainly in groups subjected to vagotomy alone or combined with splenectomy. We conclude that vagotomy in associated or not with splenectomy induces a reduction in adiposity and causes histological changes in the kidneys of obese rats.