Effect of acute triethyl lead treatment on metalloenzymes and binding characteristics of rat brain hippocampus.
Adult male rats were treated with triethyl lead chloride (TEL) by subcutaneous injection of 7.9 mg/kg body weight, 75% of the LD50. Various brain regions and serum were collected at several times after dosing. Binding of 45Ca, 3H-nitrendipine, 3H-ouabain, and 3H-glutamate to hippocampal membranes was not altered by treatment. Levels of 3',5'-cyclic nucleotide phosphodiesterase were unchanged in the hippocampus between 1 and 28 d after treatment. Three zinc-containing enzymes were assayed in the hippocampus. Leucine aminopeptidase levels were unchanged by treatment, whereas glutamate dehydrogenase activity was depressed only at the 28-d point. Superoxide dismutase activity was greatly elevated after 1 of 7 d post-dosing, but this was reversed at later times. An elevated level of this enzyme was also found in the cortex of TEL-exposed rats and in the hippocampus of rats treated with 75% of the LD50 of trimethyl lead chloride (25 mg/kg body weight). However, levels of lipid peroxide were unchanged in the hippocampus of treated rats as were values for the selenium-requiring enzyme, glutathione peroxidase. TEL does not appear to inhibit a wide range of processes relating to essential divalent cations or to cause nonspecific damage to cerebral membranes. TEL is likely to act on a limited and distinctive range of vulnerable loci.
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism; D000818:Animals; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D006624:Hippocampus / Q000201:enzymology / Q000378:metabolism*; D007854:Lead / Q000494:pharmacology*; D007931:Leucyl Aminopeptidase / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008566:Membranes / Q000378:metabolism; D008667:Metalloproteins / Q000378:metabolism*; D009543:Nifedipine / Q000031:analogs & derivatives / Q000378:metabolism; D009568:Nitrendipine; D009942:Organometallic Compounds / Q000494:pharmacology*; D010042:Ouabain / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D005971:Glutamates; D008054:Lipid Peroxides; D008667:Metalloproteins; D009942:Organometallic Compounds; D007854:Lead; D010042:Ouabain; C010360:triethyllead; D009568:Nitrendipine; D013482:Superoxide Dismutase; D005969:Glutamate Dehydrogenase; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D007931:Leucyl Aminopeptidase; D009543:Nifedipine