METABOLIC ALTERATIONS DUE TO CHRONIC EXPOSURE TO ACOUSTIC STRESS

MARIANO J. TAVERNA; GUSTAVO A. SOSA; GABRIEL CAO; ANA E. MAMANI; SILVIA MIRANDA

Mar del Platra

Congreso; LXIII REUNION CIENTIFICA DE LA SOCIEDAD ARGENTINA DE INVESTIGACION CLINICA; 2018

Our previous results showed that acoustic stress (AS) induces severe intestinal inflammation and affects glucose homeostasis in the mouse. In this study, we investigated the mechanisms involved in the altered glucose metabolism due to AS. Two-month old CBA/J male mice were subjected to basal oral glucose tolerance tests (OGTT) and then randomized into AS (n=6) and control (n=6) groups. AS mice were subsequently exposed to 24hs of noise (300Hz-70dB) at 3mo old (1 AS/week, 5 weeks), at 6mo old, and finally at 13mo olded for determining plasma levels of glucose (GLU), total and HDL cholesterol, triglycerides (TGL) and hepatic transaminases (TGP/ TGO). Fasting insulin, glucagon, GLP-1 and GIP concentrations were also determined. Main results showed: I- AS group displayed a trend toward an increased incidence of hepatic adenomas than controls (66.7% vs 16.7%, p=0,07). II- Blood glucose was roughly 70 mg/dl higher in the AS group vs. control mice (GLU = 267.4 vs. 201.0 mg/dl p=0.18). This effect was associated with higher insulin resistance (IR) assessed by TGLxGLU (p=0.0253) and TGL/HDL (p=0.0339) indexes. III- AS mice showed a diminishing in glucagon levels (p=0.0495) and a trend in insulin secretion (HOMA-beta 28.7 vs. 78.6%, p=0.15). IV- Pancreas from AS mice showed signs of hypertrophy and hyperplasia determined by fractal geometry analysis. V- AS group showed an important increase of TGL levels (976.4 vs. 123.0 mg/dl, p=0.0253). VI- Guts from AS group showed damage and alterations of villi and increased expression of TNFα. This observation is associated with lower GIP levels detected in the AS group (p=0.0275). In sum, chronic AS promotes the generation of hepatic tumors, chronic intestinal inflammation and several metabolic alterations, especially hypertriglyceridemia, that lead to pancreas disfunction in part due to lipotoxicity and reduced incretin secretion.