Potential role of inducible nitric oxide synthase (iNOS) activity in testicular dysfunction following co-administration of alcohol and combination antiretroviral therapy (cART) in diabetic rats: an immunohistochemistry study.

Diabetes, alcohol abuse, and combination antiretroviral therapy (cART) use have been reported to cause multi-organ complications via induction of oxidative stress and inflammation. Moreover, these are the most common factors implicated in male reproductive dysfunctions. This study evaluated testicular oxidative stress, inflammation, apoptosis, and germ cell proliferation in diabetic rats receiving alcohol or cART and their combination. Thirty adult male Sprague Dawley rats were divided into five groups, each consisting of six rats; control, diabetic only (DM), diabetic treated with alcohol (DM + A), diabetic treated with cART (DM + cART), and diabetic treated with both alcohol and cART (DM + A + cART). After 90 days of treatment, the rats were terminated, and the testes were extracted and processed for immunohistochemistry analysis for oxidative stress, inflammatory cytokines, apoptosis, and cell proliferation marker. In comparison to the control, oxidative stress markers, inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHDG) increased significantly in all treated groups. Expression of testicular proinflammatory cytokines, interleukin-1ß, and tumor necrosis factor-α was upregulated in all treated groups, but interleukin-6 was upregulated in DM, DM + cART, and DM + A + cART treated groups and was downregulated in the DM + A treated group. All treated animal groups showed an upregulation of apoptotic marker (caspase 3) and a downregulation of proliferation marker (Ki-67). However, Ki-67 staining intensity significantly increased in treated animals compared to the control. These findings suggest that diabetes, alcohol abuse, cART use, and their combination via iNOS activity upregulation can induce inflammation and oxidative stress in testicular tissue, stimulating germ cell apoptosis and proliferation inhibition leading to failure of spermatogenesis.

Cardiotoxicity in African clawed frog (Xenopus laevis) sub-chronically exposed to environmentally relevant atrazine concentrations: Implications for species survival.

The toxic effects of different atrazine concentrations on tadpoles and adult male African clawed frogs (Xenopus laevis) were assessed in a controlled laboratory environment following 90 days' exposure. The aim was to elucidate the danger of atrazine exposure on the cardiac tissue relative to its critical function of rhythmic contractility, fundamental for optimal blood circulation and homeostasis. Tadpoles and adult frogs were exposed to 0 µg/L (control), 0.01 µg L-1, 200 µg L-1 and 500 µg L-1 concentrations of atrazine for 90 days. Mortality was concenration-dependent and significantly increased in juvenile group (77%, 43%, 23% and 0 respectively for 500 µg L-1, 200 µg L-1, 0.01 µg L-1, and control group). While the mean juvenile heart area decreased concentration-dependently, adult frog mean heart area significantly increased in the 200 µg L-1 group only and mean heart weight change was variable across all exposure levels. Light microscopy of hematoxylin and eosin (H&E) and Mallory-Heidenhain rapid one-step staining techniques on cardiac tissue sections of the juvenile and adult frogs revealed shrinkage of cardiac muscle cells into thin wavy myocytes. Additionally, disorganized branching of muscle fibres with reduced striations were observed in 0.01 µg L-1 and 200 µg L-1 but hypertrophied myocytes, thickened intensely staining myofibrils in the 500 µg L-1 group in juvenile and adult frogs. Significant increase in the mean percentage area of connective tissue in all the treated groups (p < 0.036) were also recorded. Immunohistochemistry analysis showed decreased eNOS localization in cardiac tissue in 200 µg L-1 and 500 µg L-1 of both juvenile and adult group, suggestive of decreased cardiac contractility due to atrazine exposure. The results indicate that environmentally relevant atrazine concentrations cause significant mortality in tadpoles while concentrations ≥200 µg L-1 adversely affect cardiac muscle morphology and may induce functional perturbations in cardiac tissue contractility and consequent dysfunction which generally may have an adverse impact on their survival and longevity.