The study was conducted on 20 Holstein X Sahiwal cross bred dairy cows, with an average milk production of 2,752±113.79 liters in 284±5.75 days during a single lactation, that were divided in to two groups of 10 animals. We investigated the oxidative stress and antioxidant status during the transition period in dairy cows. In this study, plasma level of MDA was considered as an indicator of lipid peroxidation and SOD, catalase, GSH and GSHPx as antioxidants. The lipid peroxidation was significantly (p<0.001) higher in cows during early lactation as compared to the cows in advanced pregnancy. A significant positive correlation (r = +0.831, p<0.01) was determined between MDA and catalase in early lactating cows. In early lactating cows, blood glutathione was significantly lower than in advanced pregnant cows. However, early lactating cows showed non-significant negative correlation for all antioxidant enzymes with lipid peroxidation. In conclusion, dairy cows seemed to have more oxidative stress and low antioxidant defense during early lactation or just after parturition than advanced pregnant cows, and this appears to be the reason for their increased susceptibility to production diseases (e.g. mastitis, metritis, retention of fetal membranes etc.) and other health problems.

Ofloxacin, a quinolone, is an extensively used, well-tolerated antibacterial agent but has been reported to induce photosensitivity at low incidences. In the present investigation, the possible role of oxidative stress in ofloxacin-induced retinopathy in rabbits was evaluated. It was observed that ofloxacin at a dose rate of 10 and 20 mg/rabbit, twice daily for 21 consecutive days, resulted in significant elevation in the extent of lipid peroxidation and depletion of the blood glutathione levels. Marked alterations were also observed in various parameters of the glutathione-redox cycle. There was significant increase in the enzymic activity of glutathione peroxidase and glutathione reductase, whereas a significant decrease was observed in the activities of superoxide dismutase, catalase, and glutathione-S-transferase enzymes. Histopathological studies revealed retinal damage especially in the pigmented cell layer. Degenerative changes in liver and kidneys were also observed. Liver showed focal areas of necrosis, dilation of sinusoids, and cellular infiltration, whereas in kidneys, there was glomerular and tubular degeneration, suggesting impaired renal functioning.

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Aim: The present study was aimed at elucidating the distribution of various enzymes in the submandibular salivary gland of buffalo during prenatal development and correlation of these enzyme systems with the secretory activity of the gland. Materials and Methods:The study was carried out on submandibular salivary gland of 15 buffalo fetuses ranging from 11 cm curved crown-rump length (CVRL) (78 days) to 100 cm CVRL (full term). The fetuses were categorized into three groups based on their CVRL.Results: A weak activity of phosphatases and oxidoreductases was observed in the acinar cells and ductular epithelium at 11-19 cm CVRL (78-114 days). From 28 to 37 cm CVRL (136-157 days), a weak to moderate diffused granular alkaline phosphatase (AKPase) activity was observed in the seromucous acini whereas oxidoreductases showed moderate activity. The enzyme activity showed progressively increased with the advancement of the gestation period. The AKPase activity was more in the lumen of acini and along the intercellular canaliculi at 42-100 cm of CVRL (168 days -full term). Large ducts exhibited strong activity for oxidoreductases indicating increased metabolic activity of the cells. Conclusion:The fetuses of Group I showed a uniform weak activity in the acinar cells and ductular epithelium of the gland. In Group II, the enzymes showed a weak to moderate activity which progressively increased with the advancement of gestation period. The enzymes related to Group III showed a strong positive activity for enzymes which reflected higher secretory activity of the gland.

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