title: Effect of acute triethyl lead treatment on metalloenzymes and binding characteristics of rat brain hippocampus.
abstract: 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.
mesh_terms: 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
chemical_list: 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