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Evaluation Studies 2006; 27(Suppl 2): 108-111 PubMed PMID: 17159792 Citation  Keywords:  2-Methyl-4-chlorophenoxyacetic Acid:toxicity, Alanine Transaminase:blood, Alkaline Phosphatase:blood, Animals, Creatinine:blood, Dogs, Female, Herbicides:toxicity, Male, Organ Size:drug effects, Spermatogenesis:drug effects, Testis:anatomy & histology, To.   

OBJECTIVES: This study was performed to investigate the toxicity of the herbicide MCPA after repeated treatment according to OECD No 409.

METHODS: The herbicide MCPA was administrated to dogs of both sexes in daily doses: 0, 1, 5 and 15 mg/kg per os during 90 days. Clinical observations were recorded, opthalmoscopic, haematological, clinical chemistry parameters were investigated. The morphological changes were examined using pathological and histological techniques.

RESULTS: An increase in the activity of the enzyme ALT and of urea concentration was observed in the middle- and high-dose groups. ALP and creatinine were decreased in dogs of all dose groups. After 60 days of MCPA administration, the concentration of glucose decreased in the high-dose group. The relative weight of both testes was decreased in the males from the high-dose group in comparison to controls. The decrease in testes weight was associated with focal testicular atrophy and loss of spermatogenic cells in the lobuli of testes. Focal hepatocellular necrosis, inflammatory changes and mononuclear nodules were observed in the liver, predominantly in males of the high-dose group.

CONCLUSIONS: Administration of MCPA did not cause mortality and had no adverse effects on hematological parameters of animals. The results of the study showed that MCPA treatment caused inflammatory lesions in the liver, moderate damage of the kidney, and had focal adverse effect on the development of spermiogenesis. The changes were reversible....

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Journal Article 2003; 24(3-4): 209-214 PubMed PMID: 14523359 Citation  Keywords:  Animals, Immunohistochemistry, Leydig Cells:physiology, Luminescent Measurements, Male, Organ Size:physiology, Photoperiod, Rats, Rats, Wistar, Seminiferous Tubules:anatomy & histology, Testis:anatomy & histology, Testosterone:blood,.   

OBJECTIVE: The aim of this study was to examine the effects of photoperiod on testes in rat.

DESIGN: For this purpose 21 male Wistar rats were used. Animals were divided into three groups. Control rats in group I were kept under 12 hrs light: 12 hrs dark conditions (12L: 12D) for 10 weeks. Animals in group II were exposed to long photoperiods (18L: 6D), while rats in group III were exposed to short photoperiods (6L: 18D) for 10 weeks. At the end of the experiment, all animals were killed by decapitation and blood samples were obtained. Serum testosterone levels were determined with the use of a chemiluminescent enzyme immunoassay. The testes of all rats were removed and weighed. Testicular tissue was processed semiquantitative evaluation of immunohistochemical testosterone staining. Intensity of immunostaining was determined on a scale between 0 (no staining) and 5 (heavy staining). For morphometric comparison, diameters of seminiferous tubules in each group were measured.

RESULTS: In rats exposed to long photoperiods, testicular weights, diameters of seminiferous tubules and serum testosterone levels were significantly increased as compared to those in control rats. Whereas, exposure of rats to short photoperiods resulted in significantly decrease of testicular weights, diameters of seminiferous tubules and serum testosterone levels as compared to those in control rats and rats maintained in long photoperiods. Immunostaining of testosterone was moderate (3+) in control rats, heavy (5+) in rats exposed to long photoperiods and minimal (1+) in rats exposed to short photoperiods.

CONCLUSIONS: The results of our study indicate that testicular functions increase after exposure to long photoperiods and decrease after exposure to short photoperiods....

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