Analysis of protein expression and cardiac function in rats induced to diabetes mellitus: effects of treatment with triiodothyronine (T3) associated or not with insulin.

• Grant number: 22/11974-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2023
• End date: February 29, 2024
• Field of knowledge: Biological Sciences - Physiology
• Principal Investigator: Maria Tereza Nunes
• Grantee: Henrique Izaias Marcelo
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Introduction: Triiodothyronine (T3) exerts important effects on heart and glycidic metabolism. We demonstrated that alloxan-induced diabetes mellitus (DM) rats have hypothyroidism, a condition in which cardiac activity is reduced, and that their treatment with T3 promoted a reduction in blood glucose and insulin resistance, and cardiac hypertrophy without changes in blood pressure, systolic and diastolic blood pressure. We also observed that the treatment of DM animals with T3 and insulin (3U) promotes the return of blood glucose and TSH to normality. Objective: To evaluate the expression of T3 target proteins and cardiac function in DM-induced rats, as well as the effects of T3 treatment associated or not with insulin on these parameters, with the expectation that T3 and insulin treatment can, as with blood glucose, promote benefits or mitigate possible adverse effects on the heart in DM. Material and methods: Wistar rats (n=48) will be divided into control (C), diabetic (DM), DM treated with T3 (1.5 µg/100g BW) (DMT3) and DM treated with T3 and 3U insulin groups. (DMT3I). DM will be induced by a single intraperitoneal (ip) injection of alloxan (150 mg/kg BW) and animals that, after 15 days, have blood glucose e 250 mg/dL will be included in the DM groups. The animals will be treated via ip for 4 weeks. Then they will be anesthetized and evaluated for ventricular pressures and cardiac inotropism and lusitropism indices, followed by euthanasia and analysis of T3 target proteins related to cardiac function by Western Blotting.