The influence of mechlorethamine on the activity of ecto-ATPase of rat lymphocytes.
Mechlorethamine, is an immunomodulator widely used in therapy although its effect on plasma membrane - bound enzymes is unclear. In rats with an inflammatory state, an increased activity of ecto-ATPase was observed both in the B and T subpopulations of lymphocytes. A single administration of mechlorethamine (simultaneously with carrageenin - inflammation factor), either in immunomodulating (5microgram/kg) or cytotoxic (600microgram/kg) dose, decrease the enzymatic activity in both subpopulations but to higher degree in the case of cytotoxic dose. In in vitro studies, after administering mechlorethamine, a diminution of inhibiting potential of the inhibitors blocking the nucleophilic site of proteins was noticed. This confirms the hypothesis that mechlorethamine attacks the catalytic part of the ecto-enzyme containing a nucleophylic group. Classical inhibitors of apyrase - Hg(2+), cerythrosin B and suramine - did not cause any significant change in the activity of ecto-ATPase, what confirms the fact that these enzymes belong to different groups.
Department of Biochemistry, Wroclaw University of Medicine, Chalubinskiego 10, 50-368, Wroclaw Poland.
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D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology*; D008466:Mechlorethamine / Q000494:pharmacology*; D051381:Rats; D011915:Rats, Inbred BUF
D018906:Antineoplastic Agents, Alkylating; D008466:Mechlorethamine; D000251:Adenosine Triphosphatases; C027201:ectoATPase