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Biomedical subjects

S V Chandra

Publications and source records attributed to S V Chandra.

At least 19 recordsLinked to original sources
PubMed1993

Lactate dehydrogenase and glutamate dehydrogenase activities in the circumventricular organs of rat brain following neonatal monosodium glutamate.

Glutamate (glu) an excitatory neurotransmitter amino acid, is present in high concentrations in the mammalian central nervous system and is the most abundant amino acid in our daily diet. In the present study the activities of lactate dehydrogenase (LDH) and glutamate dehydrogenase (GDH) were evaluated in the circumventricular organs (CVO) of the brain in 25-day-old rats following MSG administration at a dose of 4 mg/g b.wt during the first ten days of life. The results show the LDH activity increased to 265% of that in the control (p < 0.001), whereas GDH activity was significantly decreased (p < 0.05). The great elevation in LDH, a cytoplasmic marker enzyme, is apparently due to cytoskeletal changes brought about as a consequence of glu toxicity, whereas lowered GDH activity indicates altered glu homostasis in the blood-brain-barrier deficient areas following neonatal exposure to glu.

Animals↗
PubMed1993

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.

Animals↗
PubMed1993

Effects of vitamin E on cadmium-induced locomotor dysfunctions in rats.

The effect of co-administration of vitamin E (VE) on cadmium (Cd)-induced locomotor deficits in growing rats was investigated. Intraperitoneal administration of 0.4 mg Cd/kg/d for 4 w resulted in significant decreases in time of ambulation and stereotype and numbers of stereotypic and vertical movements, but the resting time was enhanced. Administration of VE (5 mg alpha - tocopherol acetate/kg im on alternate days) to these rats effectively antagonised these locomotor deficits. The data support the hypothesis that Cd may induce oxidative stress in the CNS and that treatment with an antioxidant may be beneficial against such damage.

Animals↗
PubMed1993

Aluminum ingestion alters behaviour and some neurochemicals in rats.

Effect of aluminum (Al) has been investigated on the brain of rats exposed to this metal (500 mg Al/liter in drinking water) daily for 180 days. A significant reduction in the spontaneous locomotor activity was noticed after 90 and 180 days of Al exposure to the rats, the magnitude of the change being almost identical at both the time intervals. Aluminum exposure also produced significant deficits in acquisition and retention of learned response in active avoidance situation, these changes being time dependent. A significant retardation of the extinction of the learned task was noted in Al exposed rats especially at 180 days. There was significant increase in the lipid peroxidation and decrease in the activity of Mg(2+)-ATPase and Na+,K(+)-ATPase in the brain of rats at 180 days after Al exposure. The increase in the contents of the metal was maximum in rest of the brain region (87% of control) followed by hippocampus and cerebral cortex (59% of controls), cerebellum and corpus striatum (43% and 44% of controls, respectively) after 180 days. Whether Al is responsible to initiate neurotoxic effects by producing changes in the structure and function of the plasma membrane needs further investigations.

Adenosine Triphosphatases↗
PubMed1992

Dermal exposure to detergents.

Epidermal erosion and a 40-60% increase in histamine content of skin were observed in guinea pigs treated with different concentrations of detergents. The primary irritation indices of these animals ranged between 0.3 and 1.5. Eight human subjects with skin lesions attributable to detergent exposure were patch tested with 500 mg of detergents. A positive reaction was observed in 7 of 8 cases. In 4 cases reaction was observed within 24-48 h, while 3 cases had a severe reaction after 72 h. IgA and IgM levels were raised in 2 subjects. This study highlights the irritancy potential and toxic effects of detergent products available in Indian markets.

Animals↗
PubMed1992

Blood chromium and nickel in relation to respiratory symptoms among industrial workers.

Seventy-eight workers exposed to fumes and dust of nickel and chromium in their occupation in the glass industry were studied for respiratory symptoms in relation to nickel and chromium concentrations in their blood. A significant (p less than 0.01) association was observed between respiratory symptoms and elevated blood nickel and chromium. An interaction between nickel and chromium was found in relation to the prevalence of respiratory symptoms.

Adolescent↗
PubMed1991

A cross-sectional study of pulmonary function among workers exposed to multimetals in the glass bangle industry.

Spirometric lung functions were evaluated in 220 asymptomatic glass bangle workers exposed to the salts of various heavy metals, such as arsenic, lead, zinc, copper, manganese, cobalt, cadmium, and selenium, which are used as coloring agents in the manufacture of glass bangles. The mean values of various spirometric variables (viz. FVC, FEV1, IMBC, and PEFR) were within normal range (more than 80% of the predicted values) in both smoking and nonsmoking glass bangle workers and did not reveal any significant differences in comparison with those observed in the unexposed controls. However, variables such as FEV1/FVC% ratio, FEF25-75 and FEF75-85 were reduced significantly (p less than 0.001) in the exposed group. The reduction was more marked in the smoking glass bangle workers indicating additive effect of cigarette smoking on the small airways. The exposed group showed a significantly higher prevalence (16.3%) of respiratory impairment in comparison to that observed in the controls (7.9%) as a result of exposure to various metals in the work environment (p less than 0.01). The respiratory impairment observed in the exposed group indicated primarily restrictive pattern of pulmonary abnormality (10.4%), while the controls revealed only 1.1% prevalence of this disease (p less than 0.001). The effect of the duration of exposure on the prevalence of respiratory impairment in the glass bangle industry revealed significantly higher prevalence (p less than 0.05) in those who worked for more than 10 years (23.0%) than in those who worked for less than 10 years (10.8%) thereby indicating that the duration of exposure is directly related to the prevalence of respiratory impairment.

Adult↗
PubMed1991

Ultrastructural observations in testicular tissue of chromium-treated rats.

The administration of hexavalent chromium (2 mg/kg, ip as potassium dichromate) in adult rats daily for 15 days produced significant increases in the blood and testicular chromium levels. Although no light microscopic pathologic changes or alterations in epididymal sperm counts and motility were observed, lanthanum perfusion in treated rats revealed leakage of Sertoli-cell tight junctions under EM. A few tubules showed marked ultracellular alterations in the form of vacuolization of cytoplasm and degeneration of mitochondria in the epithelial cells. Late stage spermatids were the most affected germ cells. The mitochondrial sheath of the midpiece was vacuolated, incomplete, swollen, or broken in places. The observed alterations may result in the disruption of normal testicular physiology leading to reproductive impairment after chromium exposure.

Animals↗
PubMed1991

Lead-induced fetal nephrotoxicity in iron-deficient rats.

Lead administration (250, 500, 1000, and 2000 ppm, as lead acetate) in drinking water during fetal development (from 15 to 20 days of gestation), in normal and iron-deficient pregnant rats, revealed dose-dependent increases in the lead content of maternal blood that was more marked in iron-deficient animals. The placentae and fetuses did not show a dose-dependent increase in lead content. Lead administration revealed dose-dependent hydropic degeneration of renal proximal cells in the fetuses. The highest dose (2000 ppm lead) and iron deficiency exhibited more lead accumulation in maternal blood, placentae, and fetuses, and maximum pathologic changes in the fetal kidney when compared with the other doses and also with the fetuses of dams not deficient in iron.

Animals↗
PubMed1991

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.

Administration, Oral↗
PubMed1991

Gestational cadmium exposure and brain development: a biochemical study.

The neurochemical effects of maternally administered cadmium (50 ppm through drinking water from 0 day of pregnancy) on the whole brain of offsprings exposed during gestation were studied in 7, 14 and 21 days old rats. The developmental pattern of body weight, protein, DNA and RNA contents in brain were not affected in Cd exposed pups of any age group. Brain weights were significantly reduced in exposed pups of postnatal age of 7 and 14 days but were comparable to controls in 21 days old pups. The content of Cd increased significantly in the brain of gestationally exposed pups of 7 days and remained almost stationary throughout the experimental period. The activity of Acetylcholinesterase, Na+, K(+)-ATPase, CNPase, 5'-Nucleotidase in the brain increased significantly from 7 to 21 days of age in control animals. In experimental pups, the activity of most of the enzymes was almost comparable to controls at 7 days of age except succinate dehydrogenase, which was significantly inhibited at 7, 14 and 21 days compared to controls. The activity of other enzymes was also significantly inhibited in the brain of experimental pups compared to controls of 21 days of age indicating marked retardation in the development of these enzymes. However, these changes had no correlation with the accumulation of Cd in the brain. These studies indicate that in utero exposure to Cd may retard the development of certain neurochemicals which may have long term implications on the brain functions.

Animals↗
PubMed1991

Cardiotoxicity and hypertension in rats after oral lead exposure.

The rats were exposed to lead (0.25, 0.5 and 1.0 per cent lead acetate through drinking water) for 90 days to study its effect on some physiological and morphological parameters of the cardiovascular system. Blood lead levels increased in a dose dependent manner but heart tissue showed rise at only two higher doses in exposed animals. The two higher doses of lead resulted in an increased arterial blood pressure and calcium influx in atrial trabeculae and papillary muscles. No marked pathological or histochemical changes were observed in heart tissue excepting congestion and slightly reduced activity of succinic dehydrogenase in the highest dosed group. It was concluded that lead exposure through drinking water may produce increased arterial blood pressure and minor changes in the myocardium. Whether these changes are mediated through the effect of lead on the calcium transport needs further investigation.

Administration, Oral↗
PubMed1991

An investigation of metal concentrations in blood of industrial workers.

Pigments may contain chromates of zinc and lead, dioxide of manganese, oxides of copper and cobalt, and sulphides of cadmium. Workers engaged in the production of colored glass articles are exposed to fumes and dusts from these pigments. Exposure to these metals through inhalation may lead to a high concentration of these metals in blood. Correlations between biometric characteristics of workers and the blood levels of metals, and between blood levels of different metals were explored. Blood copper and chromium were correlated with occupational history. Significant correlations between blood levels of lead, copper, chromium and manganese were also observed.

Adult↗
PubMed1990

Testicular effects of di-n-butyl phthalate (DBP): biochemical and histopathological alterations.

Di-n-butyl phthalate (DBP) was administered to young male rats by gavage at the doses of 250, 500 and 1,000 mg/kg body weight/day for 15 days. A significant decrease in testes weight was observed at 500 and 1,000 mg/kg doses of DBP. Histopathological examination revealed marked degeneration of seminiferous tubules. The activities of testicular enzymes associated with postmeiotic spermatogenic cells, such as sorbitol dehydrogenase and acid phosphatase, were decreased significantly, while that of lactate dehydrogenase was significantly increased, coincident with degeneration of spermatogenic cells. The activities of enzymes associated with premeiotic spermatogenic cells, Sertoli cells or interstitial cells, beta-glucuronidase, gamma-glutamyl transpeptidase and glucose-6-phosphate dehydrogenase were significantly increased. Thus the alterations in activity of these testicular cell specific enzymes suggest that DBP exposure during early life could affect the testicular functions.

Animals↗
PubMed1990

Effect of hexavalent chromium on testicular maturation in the rat.

Daily intraperitoneal administration of hexavalent chromium (Cr6+; 1, 2, and 3 mg/kg intraperitoneally as potassium dichromate) in weaned rats for an entire duration of 55 and 90 days of age produced dose- and duration-dependent enzymatic and pathologic alterations. At 55 days, the pathologic changes were not seen in testes of Cr6+ treated rats, but the activities of sorbitol dehydrogenase, lactic dehydrogenase, gamma-glutamyl transpeptidase, and glucose-6-phosphate dehydrogenase were significantly altered. When the treatment was prolonged to sexual maturity, that is, 90 days of age, the alterations in enzyme activities were greater, and there were dose-dependent pathologic changes in the testes of Cr(6+)-treated rats. These alterations suggest a risk to growing testes if rats are exposed to Cr6+ during the prepubertal stage of development, which, in turn, may disturb normal testicular physiology at adulthood.

Animals↗
PubMed1990

Lead induced testicular hypersensitivity in stressed rats.

Rats were immobilized for 2 h and treated i.p. with lead Pb2+ (8 mg/kg/day) for 45 d to investigate the testicular effects of lead on rats kept under immobilization stress. Marked alteration in SDH. G6PDH activity, cholesterol and ascorbic acid contents and reduced sperm counts associated with marked pathological changes in the testis of rats were observed after combined treatment with lead and immobilization stress in comparison to either alone. An increase in the disturbances of testicular androgen synthesis seems to be responsible for enhanced testicular injury in lead induced stressed rats.

Animals↗