Influência do nervo vago subdiafragmático e do nervo vago celíaco para o pâncreas sobre a morfologia do fígado em ratos obesos-msg

Abstract

Vagal hyperactivity and alterations in splenic immune activity are common events in obesity, which has become an epidemic on a global scale and is associated with numerous comorbidities, including nonalcoholic fatty liver disease (NAFLD). Therefore, we aimed to evaluate lipid metabolism and morphological aspects of the liver associated with NAFLD in obese MSG rats submitted to splenectomy and total subdiaphragmatic vagotomy associated or not with selective celiac vagotomy. For this purpose, 30 male Wistar rats were used, which during the first five days of life received 4 g/kg weight of MSG (MSG Group). At 60 days of life the animals were submitted to different surgical procedures and distributed into 3 groups, with 10 animals in each group: MFO (False Operated); MVAG (Vagotomized); MVC (Vagotomized the celiac branch). At 150 days of age, serum biochemical parameters were evaluated, and liver fragments were removed for histological processing, triglyceride and hepatic cholesterol dosage, as well as for gene and protein expression of enzymes and transcription factors involved in lipid metabolism. It was observed that body weight, NAC and Lee index were similar in the three groups studied, however the weight of retroperitoneal fat was significantly higher in the MFO group when compared to the MVAG and MVC groups. Through histological evaluation of the liver, it was possible to observe that in the MFO group, 84% of the animals presented steatosis grade 0 and 16% grade 1, differently, 100% of the animals in the MVAG and MVC groups did not develop hepatic steatosis. It was also observed that the number of hepatocytes per field analyzed was lower in the MFO group compared to the MVAG, MVC groups. The number of non-hepatocytes per field analyzed, was similar between the MVAG and MFO animals. On the other hand in the MVC group, the number of nonhepatocytes is higher compared to the other two groups. In the hepatocyte/non-hepatocyte ratio the MFO group was similar to the other groups studied, while the vagotomized group (MVAG) was significantly higher when compared to the MVC group. The expression of TNF-α protein in the liver was similar between the groups.