Sex differences in some functional parameters in rats at the initial stage of diabetes development

Relevance. Diabetes mellitus (DM) is characterized by a long, asymptomatic course, when heart already occur and disturbances of metabolism, but do not manifest clinically. To understand the need for therapeutic prevention of possible complications of DM, it is important to study the sex-specific features of the functional state of the heart and metabolism at the DM development. Objective. To study the sex-specific features of electrophysiological parameters of the heart and general metabolism indicators in male and female rats at the initial stages of DM 2. Materials and methods. DM was induced in 20 rats of both sexes by a single intraperitoneal administration of alloxan at a dose of 150 mg/kg. Electrocardiogram (ECG) was recorded noninvasively: RR, PQ, QRS, QT intervals, P, R, T wave amplitude, and RН heart rate were assessed. Metabolic parameters were determined: volumes of consumed O2 and exhaled CO2, heat production intensity (HPI, kcal/kg/h). All parameters were assessed before administration, on days 3 and 6 after alloxan administration. Results. On day 3 after alloxan administration, blood glucose levels increased relative to baseline: 5.9 times in males and 7.0 times in females. On day 6, the glucose level was higher than the initial level: 3.2 times in males and 1.5 times in females; moreover, in males it was 2.5 times higher than in females. Pathological ECG changes — rhythm irregularity, decreased amplitude of P and T waves below the isoline, widening of the QRS complex were detected in both males and females on days 3 and 6 of diabetes. Metabolic parameters decreased only in males at all observation periods. Conclusion. In the first week of diabetes, rats showed systolic and diastolic dysfunction of the heart, decreased metabolic intensity. The most pronounced changes were noted in males, which was due to a higher glycemia than in females. 

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