Effects of Long-term Storage on Some Spermatological Parameters in Cryopreserved Bull Semen.

BACKGROUND: The effect of the long-term storage in liquid nitrogen on semen quality has not be reported. OBJECTIVE: The study measured the spermatological parameters of bull sperm after the long-term and short-term storage. MATERIALS AND METHODS: Vintage semen (obtained from 5 Brown Swiss bulls and frozen 30 years ago) and newly frozen semen collected from 5 bulls of the same breed and prepared at the International Center for Livestock Research and Training were used. For each bull, 10 straws (0.25 ml) were thawed and pooled. Sperm samples were analyzed by flow cytometry, computer assisted sperm analysis, and total oxidant-antioxidant levels were also tested. RESULTS: The ratios of necrotic (P < 0.001) and apoptotic (P = 0.006) spermatozoa, and the ratios of total antioxidant status (TAS) and total oxidant status (TOS) were significantly higher (P < 0.001) in long-term frozen spermatozoa. However, the early necrotic ratios (P < 0.001), velocity average pathway (VAP) (P = 0.008) and velocity curvi linear (VCL) (P = 0.01) values of long-term frozen semen were lower compared with short-term frozen semen. While necrotic and apoptotic spermatozoa ratios and total oxidant level were higher, VAP/VCL ratios were lower in long-term frozen sperms compared to short-term frozen semen. CONCLUSION: Long-term storage of sperm may adversely affect the spermatological and oxidative parameters of Brown Swiss bull spermatozoa.

High cholesterol diet leads to oxidant load and peroxidation in the rabbit kidney tissue.

OBJECTIVES: The aim of this study was to investigate possible effects of high cholesterol diet on oxidant/antioxidant status in rabbit kidney tissues. BACKGROUND: Although a number of experimental animal models have suggested that hyperlipidemia is associated with progressive kidney failure data remain sparse on the role of dietary cholesterol intake on kidney disease. METHODS: Twelve male New Zealand albino rabbits were randomly divided into two groups (control and cholesterol). Both groups were fed on a standard laboratory diet. Animals in the cholesterol group additionally received cholesterol (1 g/kg/day), orally. The study period was 12 weeks. Activities of catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), nitric oxide synthase (NOS), xanthine oxidase (XO), paraoxonase (PON), adenosine deaminase (ADA) enzymes and levels of malondialdehyde (MDA) and nitric oxide (NO) were measured in kidney tissue samples. Histological examination of the kidney tissue samples was also done. RESULTS: SOD, GSH-Px and XO enzyme activities were found to be decreased and NOS and PON activities increased significantly in cholesterol group compared to controls. As an indication of oxidation, MDA levels were found to be increased in cholesterol group. Histological examination revealed some derangements in the kidney tissue. CONCLUSION: High cholesterol diet creates oxidant load and causes peroxidation, which in turn, leads derangements in the rabbit kidney tissue (Tab. 2, Fig. 2, Ref. 69).