Effects of combined training with intermittent hypoxia on physiological, molecular responses and performance of Wistar rats

• Grant number: 20/11573-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: January 01, 2025
• End date: September 30, 2025
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Marcelo Papoti
• Grantee: Carlos Dellavechia de Carvalho
• Host Institution: Escola de Educação Física e Esporte de Ribeirão Preto (EEFERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The aim of this project will be to investigate the effects of running training associated with hypoxic conditions (~ 12% O2), followed by a tapering period. Physiological and molecular responses will be evaluated in the physical and cognitive performance of Wistar Hannover rats. Such tests will be done in the acute and chronic phases. During the acute phase, 66 rats will be used, which will be submitted to all combinations of training and hypoxia and possible changes in performance will be evaluated. In the chronic phase, 36 animals will be subjected to nine weeks of training programs based on the same exercise combinations of the acute phase (which will be done by five efforts of 5'20" with 2'40" of passive interval and intensity of 90% of the maximum running speed); in addition to two control groups (exposed to hypoxia or not) that will not perform physical activity. The following items will be quantified: (i) blood parameters: red blood cells, hematocrit, hemoglobin, and erythropoietin (EPO) and; (ii) Levels of enzyme expression (contained in the long digital extensor and soleus muscles) via Western blot / immunoblotting: hypoxia-inducible factor 1 alpha (HIF-1¿), hexokinase 2, citrate synthase, lactate dehydrogenase. Two-way ANOVA analysis of variance was chosen for comparison between groups and a Pearson correlation test for possible associations and Bayesian statistics will be used for comparisons.