Saurabh Chandra

Lead induced ultrastructural changes in the testis of rats.

Oral lead administration (250 ppm lead acetate through drinking water) to weaning male rats for 70 days resulted in the marked accumulation of this metal in blood and testicular tissue. No marked changes were evident in light microscopy. Ultrastructural changes were revealed in the form of vacuolisation of Sertoli cell cytoplasm and increase in the number and size of lysosomes. Some of the vacuoles contained vesicle like structures. Although there was no impairment of spermatogenesis, the changes in the Sertoli cells may lead to changes in spermatogenesis after chronic exposure.

Manganese induced testicular changes in monkeys

Oral administration of manganese chloride (25 mg/kg b. w. daily) to monkeys for a period of 18 months produced congestion and marked increase in weight of testis. Histopathologic examination revealed interstitial oedema and degeneration of seminiferous tubules. Activities of succinic dehydrogenase, glucose-6-phosphate dehydrogenase and acid phosphatase were significantly inhibited whereas NADH-diaphorase and alkaline phosphatase activities showed only slight inhibition in seminiferous tubules of treated monkeys. It was concluded that chronic exposure to manganese does not produce sever degenerative changes in the testis earlier than metal induced encephalopathy in primates.

Genotoxic Effects of Diuron Contaminated Soil on the Root Meristem Cells of Allium sativum: A Possible Mechanism of Chromosome Damage

Diuron, a persistant substituted urea herbicide, was tested in the root meristem cells of Allium sativum for the possible cytogenetic effects and to compare the sensitivity with Allium cepa. Test concentrations of diuron 22.5, 45.0, and 90.0 ppm were mixed in soil and the cloves of A. sativum were placed over diuron-contaminated soils. Root meristematic cells were sampled at 48 h to score Mitotic/Chromosomal aberrations and to analyze the effect on mitotic index (MI). Microscopic analyses revealed significant and dose-dependent induction of mitotic as well as chromosomal breaks. The frequency of mitotic aberrations was every time found much higher than that of chromosomal aberrations. Mild percentage of Micronucleated and Binucleated cells was observed, as MI also declined during the analysis. Based on the data of valence charge densities on the atoms of herbicide molecule and spectroscopic studies, a possible mechanism of interaction of diuron with DNA molecule for chromosomal aberrations has been proposed.

Embryo-Fetal Development Influenced by Lead Exposure in Iron-Deficient Rats

Lead administered (250, 500, 1000 and 2000 ppm Pb as lead nitrate) through drinking water from the 6th to the 14th day of gestation in iron-deficient rats, resulted in a significantly reduced litter size, reduced fetal weight and a reduced crown-rump length, increased resorption and a higher blood-lead uptake in those groups receiving 1000 and 2000 ppm Pb. These animals also had a higher placental lead uptake. However, the level was the same in both groups. Fetal lead uptake remained the same whether or not 2000 ppm lead was given to an iron-deficient or normal iron groups of mothers. This indicates that iron-deficiency renders female rats more susceptible to inducing embryo- and feto-toxicity when given lead through their drinking water.

Evaluation of 5-aminoisoquinoline (5-AIQ), a novel PARP-1 inhibitor for genotoxicity potential in vitro and in vivo.

5-aminoisoquinoline (5-AIQ) is an active PARP-1 inhibitor as well as an important functional group various drugs. Quinolines are generally known as mutagenic and carcinogenic in various in vitro and in vivo systems, while both positive and negative findings are available on the mutagenic potential of several isoquinolines. Since no literature is available on the genotoxicity of 5-AIQ, a battery of tests were conducted, in accordance with relevant OECD protocols, such as bacterial reverse mutation test, in vitro chromosomal aberration test, and bone marrow micronucleus test in mouse. These studies demonstrate that 5-AIQ does not possess genotoxic activity both with in vitro and in vivo systems. The findings substantiate the therapeutic value of 5-AIQ.

Histochemical and histopathological changes in the skin of rats after manganese application

Summary Histochemical and histopathological changes in the skin of rats, after the daily application of manganese chloride solution for a period of 90 days, are reported. These alterations consist of hyperkeratinization and marked proliferation of hair follicles. The application of manganese chloride solution produced marked inhibition in the activities of succinic dehydrogenase, glucose-6-phosphate dehydrogenase and cytochrome oxidase, however no effect was noticed in the activities of acid and alkaline phosphatases, melanin deposition and the contents of nucleic acids in the skin of rats. The intensity of staining reaction for sulfhydryl groups appeared markedly increased due to the proliferation of the hair follicles in the painted skin. The absence of any effect on the cutaneous melanin appears of significance since manganese has been found to reduce neuromelanin in rhesus monkeys. The implications of these findings are discussed.