Effects of mercuric chloride on several scavenging enzymes in rat kidney and influence of vitamin E supplementation.

Administration of HgCl2 at a dose of 5 mg/kg body weight/day for 15 days to male albino rats brought about a marked depression of the scavenging enzymes viz. glutathione peroxidase and glutathione S-transferase, in kidney. There was an adaptive rise in the levels of catalase and no increased lipid peroxidation was observed.

Lysis of nitrofurantoin-resistant strain of Vibrio el tor.

Both nitrofurantoin-sensitive and nitrofurantoin-resistant strains of Vibrio el tor were found to lyze in the presence of Tris-EDTA at alkaline pH. The rate of lysis was appreciably enhanced by lysozyme. The amounts of intracellular components, viz.

Studies on the induction of histidase in Vibrio el tor under nitrofurantoin resistant conditions.

Studies on the induction of histidase were made with normal and nitrofurantoin resistant strains of Vibrio el tor. Nitrofurantoin resistant strains showed decreased level of induction in comparison to normal Vibrio el tor. The effect of different inhibitors like actinomycin D, chloramphenicol, tetracycline, nitrofurantoin and rifampicin on histidase induction was also studied.

Neurotoxicity of lanthanum chloride in newborn chicks.

Acute intraperitoneal administration of lanthanum chloride to newborn chicks at the single dose of 250 mg/kg body weight inhibits calcium binding to brain synaptosomal membrane. There is also marked depression in the activities of neural Ca2+-ATPase, Mg2+-ATPase, and cholinesterase after acute lanthanum chloride intoxication. The inhibition of these enzymes in relation to depletion of calcium binding to the synaptosomal membrane has been discussed.

Effects of L-ascorbic acid supplementation on dieldrin toxicity in rats.

Chronic dieldrin administration to rats (5 mg/kg/day) produced pathological changes in liver and kidney tissues. Dieldrin treated rats showed high levels of liver ascorbic acid and increased activities of inorganic pyrophosphatase in brain and glucose-6-phosphatase in liver. The activities of Mg2+-ATPase in liver and acetylcholinesterase in brain were decreased under toxic doses of dieldrin.

Effect of dieldrin on rat liver plasma membrane enzymes.

Dieldrin, an organochlorine insecticide, when administered orally to male albino rats at a dose of 5 mg/kg body weight/day for 15 days inhibits the enzyme Mg2+ -ATPase and stimulates the activity of 5'-nucleotidase and NADH-dehydrogenase in liver plasma membrane. L-ascorbic acid supplementation offers some protection in relation to the inhibition of Mg2+ -ATPase.

Studies on alkaline phosphatase, catalase and z-galactosidase in Vibrio el tor under normal and rifampicin resistant conditions.

Alkaline phosphate, catalase and beta-galactosidase activities of Vibrio et tor were decreased after acquisition of resistance towards rifampicin. Zn2+, Mn2+ and EDTA inhibited alkaline phosphatase which is most active with p-nitrophenylphosphate as substrate while Mg2+ was found to suppress alkaline phosphatase activity. Removal of EDTA however, restores the original activity.

Studies on superoxide dismutase activities in virulent and avirulent strains of Agrobacterium tumefaciens and also in normal and crown gall tumor cells of Bryophyllum calycinum.

Superoxide dismutase activity in virulent strains of Agrobacterium tumefaciens was found to be higher than that in avirulent strains. Polyacrylamide gel electrophoresis revealed two isoenzymes in both these strains. These isoenzymes are suggested to be iron and manganese containing superoxide dismutases.

Effects of high dose application of lindane to rats and influence of L-ascorbic acid supplementation.

Oral application of lindane at a dose of 2 mg/100 g body weight of rat/day for 15 days produced alterations in the activities of several enzymes viz, glutamate oxaloacetate transaminase, alkaline phosphatase, acetylcholinesterase and inorganic pyrophosphatase in different organs and serum. Histological changes in liver and kidney tissues and changes in whole liver and liver plasma membrane lipids were also noted by chronic administration of lindane. Partial alleviation of the toxic symptoms with respect to some of these parameters were noted by high dose administration of L-ascorbic acid.

Protective effect of L-ascorbic acid in lindane intoxicated rats.

Administration of lindane at a dose of 20 mg/kg body weight/day for 15 days to male rats brought about marked growth retardation. Succinic dehydrogenase, Mg2+-ATPase and glucose-6-phosphatase activities were inhibited in different fractions of liver tissues. Mg2+-ATPase, alkaline phosphatase and NADH-dehydrogenase activities were also inhibited in the liver plasma membranes of the lindane treated animals.

Lysozyme in Schwartz and Moloney virus-induced lymphoblastic leukaemia.

Studies have been made on lysozyme in serum and tissue homogenates in normal and leukaemic mice. An increase in serum lysozyme level occurred in mice bearing both strains of leukaemia as compared to the normal counterparts. Moreover, the elevated enzyme levels seem to be related to the rise in neutrophils in peripheral blood.

Biochemical studies on molybdenum toxicity in rats: effects of high protein feeding.

Chronic oral administration of ammonium molybdate in rats markedly retarded the growth rate of rats and high protein diet could partially reverse this condition. The activities of several enzymes viz. acid phosphatase, alkaline phosphatase, glucose-6-phosphatase, succinic dehydrogenase, glutamate oxaloacetate transaminase, inorganic pyrophosphatase and acetylcholinesterase in different tissues and serum levels of luteinizing hormone, follicle stimulating hormone, prolactin and cortisol are altered due to the toxicity conditions and high protein diet fed group of animals showed almost normal values in respect of a few of these parameters.

Studies on the protective effects of L-ascorbic acid in chronic chlordane toxicity.

The influence of extraneous supplementation of L-ascorbic acid in chronic chlordane toxicity has been studied in rats. Oral administration of chlordane brings about a marked growth retardative effect, stimulates vitamin C synthesis in the system, elevates the vitamin C status of the liver and kidney tissues and also the urinary excretion. It inhibits the activities of acid and alkaline phosphatases, SDH and Mg2+-ATPase of both hepatic and renal tissues.

Studies on superoxide dismutase activity and modulation of nitrofurantoin resistance by hyperbaric oxygen in Vibrio el tor.

Superoxide dismutase, purified from Vibrio el tor, was found to have a molecular weight of 40,000. The enzyme was insensitive to KCN and NaN3 but was completely inhibited by H2O2 suggesting it to be an iron containing enzyme. Besides its ability to counteract the bactericidal effect of hyperbaric oxygen, the purified enzyme could to some extent prevent the enhanced bactericidal effect of nitrofurantoin in the presence of hyperbaric oxygen.

Studies on membrane ATPase activity and lipid level in vibrio el tor under normal and nitrofurantoin resistant conditions.

Nitrofurantoin resistance brought about decreased level of membrane bound ATPase activity in Vibrio el tor as compared to the normal strain while phospholipid as well as total lipid levels in the membrane fraction was increased. Mg++ was found to be the mose effective co-factor for ATPase. At higher concentrations of sodium and potassium ions, ATPase of normal and nitrofurantoin resistant Vibrio el tor responded quite differently.