Protective effects of different types of bariatric surgeries on myocardial ischemia-reperfusion injury in non-obese non-diabetic rats

Abstract

Abstract Introduction Prior bariatric surgery (BS) significantly improves survival after myocardial infarction (MI). We assume that reduction in fatal MI after BSs could be attributed to the infarct size-limiting effect of the interventions and that this effect is not associated with an improvements in the diabetes mellitus and obesity. Purpose The aim of the study was to evaluate the infarct-limiting effect of various types of bariatric surgery in non-obese non-diabetic rats. Methods Rats were randomized into the following groups: no surgery (CON), sham surgery (SHAM), Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and ileal transposition (IT). 10 weeks after BS, the animals were subjected to ischemia-reperfusion, followed by histochemical determination of infarct area (IA) and no-reflow zone. At the 90th minute of reperfusion, all animals were injected intravenously with indocyanine green at a dose of 1 mg/kg to measure size of no-reflow zone. Results None of bariatric surgery procedures led to body weight reduction. A temporal high postprandial glucose was observed during oral glucose tolerance test (OGTT) in SG and RYGB rats at 30th minute followed by decrease at 120 minutes in comparison with SHAM. Blood insulin concentration increased at 60th minutes in response to OGTT glucose in the SG group compared to CON and SHAM. On the contrary, there was a decrease in insulin level in the IT group after 60 and 120 minutes. In RYGB, basal leptin was low at 120 minutes after glucose administration, while in SG it decreased at 60 and 120 minutes compared with CON and SHAM. Compared to the SHAM, the rats with RYGB and SG had lower IA by 22% and 10% and no-reflow size by 38% and 32%. Conclusions We demonstrated that both bariatric surgeries procedures, RYGB and SG, increase myocardial tolerance to ischemia-reperfusion injury in rats without diabetes and obesity. The infarct-limiting effect was accompanied by a significant decrease in basal plasma leptin level. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health Care of Russian Federation. Governmental funding research