The relationship of high fructose corn syrup containing drinks through insuline resistance on polycystic ovary syndrome in experimental rat model

Aim: We aimed to evaluate the effects of high fructose corn syrupe ( HFCS) drinks on insulin reistance and polycystic ovary syndrome (PCOS) etiopathogenesisin the present study. Materials and method: This study was approved by the Experimental Ethical Committee of Celal Bayar University. Forty?one Wistar Albino 150-350 grams female rat were included in the study. Rats were fed with different drinks for 6 weeks according to the 5 study groups;control group (n=11) normal water drink,glucose group (n=7) %30(w/v) glucose drink, fructose group (n=7)%30(w/v) fructose drink, HFCS-55 group (n=8) %30(v/v) HFCS-55 drink, and HFCS-90 group (n=8) %30(v/v) HFCS-90 drink. Female rats were screened for their oestrus phase every morning by micrscopic evaluation of the vaginal smear. Rats at oestrus phase were sacrified, intracardiac blood samples were obtained and ovaries were removed for histopathologic evaluations. Serum glucose, insülin, leptin, cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, free testosterone, leptin, malondialdehyde, superoxide dismutase, 8-hydroxy-2deoxyguanosine and eritrocyte glutatione peroxidase concentrations were analysed. Leptin, insülin, superoxide dismutase and 8-hydroxy-2deoxyguanosine were analysed by ELISA methods. Glucose, cholesterol, triglyceride, HDL-cholesterol malondialdehyde and glutatione peroxidase were analysed by photometric methods. Free testosterone were analysed by radioimmun assay methods. LDL-cholesterol were calculated by Fridewald formula and HOMA index (glucoseXinsulin/405). In histopathological evaluation hemotoxylane eosin dye, TUNEL, eNOS and VEGF immunohistochemical dyes were performed to ovary samples. Statistical evaluation were perfrmed using SPSS 16.0software. Results: Fasting glucose concentrations were found to be significantly elevated in fructose, HFCS-55 and HFCS-90 groups. HOMA and leptin concentrations were found to be significantly elevated inHFCS-55 and HFCS-90 groups. Triglyceride were found to be elevated in HFCS-90 group. Antioxidant enzymes were found to be elevated in fructose, HFCS-55 and HFCS-90 groups. Morphometric evaluation scores of the ovaries were found to be significantly elevated fructose, HFCS-55 and HFCS-90 groups compared to control group. Discussion: Fructose supplementation has shown to result in weight gain in previous studies in literature. In the preent study we observed significant weight gain in glucose, fructose and HFCS-90 groups. Although decrease in hepatic insulin activity and insulin sensitivity were observed in fructose fed rats in literature, acute fructose supplementation result in decreases in leptin and insulin concentrations, fructose supplementation for 6 months lead to inulin increase in additional studies. In the present study we found increases in HOMA index in HFCS 55 and HFCS 90 groups. It has been shown that fructose consumption did not eleate leptin concentrations in short term. Although leptin concentrations were shown to be correlated with BMI and insulin resistance in literature, contradictory studies also revealed that leptin has changed independent of BMI and insulin resistance. In the present study leptin levels were found to be significantly elevated in HFCS 90 and HFCS 55 groups. These results revealed that leptin increases could be independent from weight gain and may be related to insulin resistance. Antioxidant enzymes were found to be elevated in fructose, HFCS-55 and HFCS-90 groups and we believe this is due to compansate the increase in oxidative stress in these groups. Macroscopic findings show that HFCS suplementation resulted in experimental PCOS in histological evaluation. eNOS scores were found to be increased inHFCS 90 and HFCS 55 groups compared to control group. We believe eNOS increase is may be due to oxidative stress resulted from HCFS suplementation. Apoptotic cell increase due to HFCS supplementation detected by TUNEL method has been shown in ovary in previous studies in literature. We found similar increase in TUNEL score in fructose, HFCS 90 and HFCS 55 groups. VEGF score, a neovascularisation marker, has been shown to increased in fructose, HFCS 90 and HFCS 55 groups in the present study. In conclusion, we believe that HFCS supplementation has resulted in significant injury in ovaries as detected by increased TUNEL, VEGF, .eNOS scores and increased HOMA index, trigyceride, leptin, and antioxidant marker concentrations.