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Biomedical subjects

D K Saxena

Publications and source records attributed to D K Saxena.

At least 73 records · Page 4Linked to original sources
PubMed1986

Embryotoxic and teratogenic effects of interaction of cadmium and lindane in rats.

Embryotoxic and teratogenic effects of cadmium and lindane were studied in rats. Cadmium or lindane alone did not produce any significant malformations in the 20 day old foetuses whereas their combination caused significant reduction in the body weight of dams and pups and increased total embryonic deaths. Skeletal deformities like wavy ribs, reduced skull ossification and reduced caudal vertebrae were potentiated in coexposure group. The study indicated that the simultaneous exposure to cadmium and lindane may have more deleterious effects on the developing foetus compared to either alone.

Abnormalities, Drug-Induced↗
PubMed1981

Behavioral and neurochemical changes in rats simultaneously exposed to manganese and lead.

Groups of rats were exposed simultaneously to manganese chloride (3 mg Mn2+/ml water) through drinking water and lead acetate intraperitoneally at dosages of 5.0, 8.0 and 12.0 mgPb2+/kg daily for a period of 14 days. The magnitude of changes in the behavioral pattern, contents of biogenic amines and accumulation of lead in the brain of rats simultaneously exposed to the two metals was significantly greater than observed in rats after exposure to either of the metals alone. A definite dose-response relationship was, however, noticed only with the changes in the motoractivity, norepinephrine, 5-hydroxytryptamine levels and in the accumulation of lead in rats simultaneously exposed to manganese and lead. The lowering in the contents of norepinephrine after combined treatment was found to be related with the decrease in the motoractivity in the rats. The exact role of depression in the levels of dopamine and 5-hydroxytryptamine in inducing marked impairment in learning ability and increased aggressive behavior in rats after the combined exposure to manganese and lead could not be ascertained. The overall analysis of the data indicated that the simultaneous exposure to manganese and lead, particularly with highest dose of the latter, may produce serious derangements in the behavioral pattern and levels of biogenic amines in the brain of rats.

Agonistic Behavior↗
PubMed1981

Effect of manganese and copper interaction on behavior and biogenic amines in rats fed a 10% casein diet.

Manganese chloride (1 mg manganese/ml drinking water) and copper sulphate (250 mg copper/kg diet) were administered daily for 30 days to growing rats maintained on a 10% casein diet. Manganese in combination with copper produced impairment in the learning ability and memory of rats in either dietary group, with greater alterations in those receiving a 10% casein diet. Hyperactivation due to the combined effects of the metal ions was identical in both dietary groups. The behavioral aberrations were associated with a marked accumulation of Cu in the brain of rats receiving the 10% casein diet. Combined exposure of Mn and Cu also produced a greater elevation in the levels of dopamine (DA) and norepinephrine (NE) and a depression of 5-hydroxytryptamine (5-HT) in the brain of animals fed with a 10% casein diet compared to the animals receiving the 21% casein diet. Thus the animals receiving the 10% casein diet appear to be more vulnerable to the neurotoxic effects of a combined exposure to manganese and copper. However rats maintained on the 21% casein diet and receiving both manganese and copper showed almost identical changes to those observed after manganese administration alone.

Animals↗
PubMed1975

Manganese induced hepatic lesions in carbon tetrachloride pretreated rats.

Manganese sulphate (6 mg/kg) was administered intraperitoneally daily for 30 days in carbon tetrachloride pretreated rats. Histological and histochemical studies in liver tissue revealed extensive damage to hepatic parenchyma in these rats as compared to lesions produced by manganese sulphate alone. These findings suggest that workers, with liver dysfunction ergated in manganese industry may be more susceptible to the toxic effects of this metal.

Administration, Oral↗
PubMedDate not supplied

Lead-induced cell death in testes of young rats.

Lead is a well-documented testicular toxicant. The present work was planned to study the occurrence of germ cell death after lead administration. Young growing rats were treated with 5, 10 and 20 mg kg(-1) body weight of lead for 2 weeks. Cell death was assessed by employing in situ TUNEL staining, DNA electrophoresis and morphological examination of the tubules. The results showed that Pb induced significant numbers of germ cells to undergo apoptosis in the seminiferous tubules of rats treated with 20 mg kg(-1) body weight. However, DNA fragmentation was not detected at any of the doses. The level of lead accumulation in the testis increased in a dose-dependent manner.

Administration, Oral↗
PubMedDate not supplied

Comparative toxic potential of market formulation of two organophosphate pesticides in transgenic Drosophila melanogaster (hsp70-lacZ).

This study investigated the working hypothesis that two widely used organophosphate pesticides; Nuvan and Dimecron, exert toxic effects in Drosophila. Transgenic D. melanogaster (hsp70-lacZ) was used as a model for assaying stress gene expression and AchE activity as an endpoint for toxicity and also to evaluate whether stress gene expression is sufficient to protect against toxic insult of the chemicals and to prevent tissue damage. The study was extended to investigate the effect of the pesticides on the life cycle and reproduction of the organism. The study showed that Nuvan affected emergence of the exposed flies more drastically than Dimecron and the effect was lethal at the highest tested concentration (0.075 ppm). While Nuvan at 0.0075 and 0.015 ppm concentrations affected reproduction of the flies significantly, the effect of Dimecron was significant only at 0.015 and 0.075 ppm. Nuvan-exposed third-instar larvae exhibited a 1.2-fold to 1.5-fold greater hsp70 expression compared to Dimecron at concentrations ranging from 0.0075 to 0.075 ppm following 12 and 18 h exposure. While maximum expression of hsp70 was observed in Nuvan-exposed third-instar larval tissues following 18 h exposure at 0.075 ppm, Dimecron at the same dietary concentration induced a maximum expression of hsp70 following 24 h exposure. Further, concomitant with a significant induction of hsp70, significant inhibition of AchE was observed following chemical exposure and temperature shock. Concurrent with a significant decline in hsp70 expression in Nuvan-exposed larvae after 48 h at 0.075 ppm, tissue damage was evident. Dimecron-exposed larvae exhibited a plateau in hsp70 induction even after 48 h exposure and moderate tissue damage was observed in these larvae. The present study suggests that Nuvan is more cytotoxic than Dimecron in transgenic Drosophila melanogaster.

Acetylcholinesterase↗
PubMedDate not supplied

Nuclear alterations during acrosomal cap formation in spermatids of lead-treated rats.

Ultrastructural studies were conducted to assess the effect of lead (Pb 5 mg/kg IP for 16 days as lead acetate) on rat spermiogenesis. Results showed swelling of nuclei and acrosomes in round spermatids. In Sertoli cells, nuclei appeared fragmentated, whereas the cytoplasm exhibited a vacuolated appearance and a few structures delimitated by a double membrane that contain parallelly arranged microtubules and cross-striated fine fibrils. Sertoli cell tight junctions remained intact. There was no significant change in epididymal sperm motility and counts, although testicular and blood lead levels were found to be elevated after lead exposure. These results suggest that spermatid and Sertoli cell damage may lead to disruption of spermiogenesis in lead-intoxicated rats.

Acrosome↗
PubMedDate not supplied

Lead and cadmium concentration in the seminal plasma of men in the general population: correlation with sperm quality.

The concentration of lead and cadmium in the seminal plasma of men in the general population, including fertile and infertile subjects, was measured. Semen samples were categorised as demonstrating oligospermia (sperm concentration < 20 x 10(6)/ml), asthenospermia (<50% motilesperm), oligoasthenospermia (a combination of the two criteria), and azoospermia (no sperm). An increase in lead and cadmium levels was observed in infertile men and there was a significant negative correlation of cadmium and lead semen concentration with sperm motility and sperm concentration in oligoasthenospermic men.

Adult↗
PubMedDate not supplied

Cytotoxic effect of endosulfan on rat Sertoli-germ cell coculture.

Endosulfan induced testicular impairment has been reported in vivo in rats. The present study was conducted to evaluate the cytotoxic effects of endosulfan in vitro employing rat testicular cells in culture, that is Sertoli-germ cell coculture. Cytotoxic changes induced by endosulfan (0, 2, 20, 40, and 80 microM) in mixed cultures of Sertoli and germ cells were seen after 24 and 48 h of treatment. Endosulfan led to an increase in germ cell detachment from the Sertoli cell monolayer in a dose dependent manner. A loss in the viability of detached cells was observed in all treated groups. Substantial leakage of the cytosolic enzyme lactate dehydrogenase was observed in the medium after 24 and 48 h endosulfan treatment at concentrations of 20 to 80 microM. The extent of toxicity was greater after 48 h of treatment.

Animals↗