Effect of naringin on oxidative stress and endoplasmic reticulum stress in diabetic cardiomyopathy / 中国中药杂志

To explore the protective effect of naringin(Nar) on the injury of myocardium tissues induced by streptozotocin(STZ) in diabetic rats and the relationship with oxidative stress and endoplasmic reticulum stress(ERS)， the male SD rats were intraperitoneally injected with streptozotocin(STZ， 60 mg·kg⁻¹) to establish the diabetic rat model and then randomly divided into the type 1 diabetic rat group(T1DR)， the low-dose Nar group(Nar25)， the middle-dose Nar group(Nar50) and the high-dose Nar group(Nar100). The normal rats were designed as control group(Con). Nar25， Nar50， Nar100 groups were orally administered with Nar at the doses of 25.0， 50.0， 100.0 mg·kg⁻¹ per day， respectively， while the normal group and the T1DR group were orally administered with saline. At the 8th week after treatment， fasting plasma glucose and heart mass index were measured. The pathological changes in myocardial tissues were observed by microscope. The cardiac malondialdehyde(MDA) level and superoxide dismutase(SOD) activities were measured. The gene and protein expressions of glucose-regulated protein 78(GRP78)， C/EBP homologous protein(CHOP)， cysteinyl aspartate-specific proteinase 12(caspase 12) were detected by qRT-PCR and Western blot. According to the results， compared with control group， the myocardial structure was damaged， the content of MDA was increased， while the activities of SOD were decreased(<0.05) in T1DR group. GRP78， CHOP and caspase 12 mRNA and protein expressions were increased significantly in T1DR group(<0.05， <0.01). Compared with T1DR group， myocardial structure damage was alleviated in Nar treatment group. The content of MDA was decreased， while the activities of SOD were increased significantly. The mRNA and protein expressions of GRP78， CHOP and caspase 12 were increased， especially in middle and high-dose groups(<0.05， <0.01). After treatment with Nar for 8 weeks， myocardial structure damage was obviously alleviated in Nar treatment groups. The content of MDA was decreased， while the activities of SOD were increased significantly in myocardial tissues. The mRNA and protein expressions of GRP78， CHOP and caspase 12 were increased， especially in middle and high-dose groups(<0.05， <0.01). The findings suggest that Nar may protect myocardium in diabetic rats by reducing mitochondrial oxidative stress injuries and inhibiting the ERS-mediated cell apoptosis pathway.

Changes of key enzymes involved in testosterone synthesis in testes of early diabetic mice / 药物评价研究

Objective Type 1 diabetes mice model was established to investigate the changes of key enzymes involved in testosterone synthesis in testes of early diabetic mice.Methods Tatolly 20 male C57 mice were randomly divided into two groups:control and diabetic groups,and the diabetes mice were ip administered with a single dose of 150 mg/kg Streptozotocin.Four weeks after confirmation of diabetic model,the serum and testis were collected for further study.The qRT-PCR method was used to measure the expression of LHR and steroidogenesis synthetase StAR,P450scc,3β-HSD6,P450c17a1,and 17β-HSD3 mRNA.ELISA assay was performed to measure the levels of testosterone and luteinizing hormone (LH) in serum,and the enzymatic activities of 3β-HSD1,1P450c17 and 17β-HSD3 in testis tissue.Results Compared to control group,the levels of testosterone and LH of diabetic group declined significantly (P ＜ 0.05) after four weeks.The mRNA levels of LHR,StAR,CYP11a1,Hsd3b6,CYP17a1 and Hsd17b3,and enzymatic activities of 3β-HSD6,P450c17 and 17β-HSD3 were also decreased significantly compared with control group (P ＜ 0.05,0.01 and 0.001).Conclusion Expression of key enzymes of testosterone synthesis in testis of early diabetic mice decreases significantly.