Changes in free amino acids in peripheral blood (PB) lymphocytes and polymorphonuclear (PMN) leukocytes after treatment with diazepam.

The effect of single and chronic (15 days) i.p. injections (1.0 and 8.0 mg/kg) of diazepam (DZ) on free amino acid profile in peripheral blood (PB) lymphocytes and polymorphonuclear (PMN) leukocytes of male Wistar Albino rats were investigated. Depletion of some free amino acids was observed in the lymphocytes (mixed T- and B-lymphocytes) and PMN leukocytes (91-95%) neutrophils especially after chronic DZ-treatment. A dose-dependent depletion in the lymphocyte amino acids, Tau, Gly, Ala, Met and Ile, was found after both acute and chronic DZ-treatment. A similar depletion of Tau, Asp, Glu and Met appeared in the PMN leukocytes after single doses as well as chronic DZ-treatment. These results suggest that administration of 1.0-8.0 mg/kg of DZ in single dose or after chronic administration may interfere with the transport of certain important amino acids and/or protein turnover in PB lymphocytes and PMN leukocytes. On the other hand, the basic amino acids Lys, His and Arg were significantly increased in PMN leukocytes after chronic administration of 1.0 mg/kg DZ. It was suggested that the increased levels of the basic amino acids in the neutrophils may interact with the intracellular changes in pH that normally accompany the respiratory burst.