Identification of metabolic pathways involved in the biotransformation of tolperisone by human microsomal enzymes.

The in vitro metabolism of tolperisone, 1-(4-methyl-phenyl)-2-methyl-3-(1-piperidino)-1-propanone-hydrochloride, a centrally acting muscle relaxant, was examined in human liver microsomes (HLM) and recombinant enzymes. Liquid chromatography-mass spectrometry measurements revealed methyl-hydroxylation (metabolite at m/z 261; M1) as the main metabolic route in HLM, however, metabolites of two mass units greater than the parent compound and the hydroxy-metabolite were also detected (m/z 247 and m/z 263, respectively). The latter was identified as carbonyl-reduced M1, the former was assumed to be the carbonyl-reduced parent compound.

A rapid centrifugation method for the isolation of polymorphonuclear leucocytes from human blood.

A rapid one-step gradient centrifugation method to prepare PMN leucocytes has been worked out by which a 98--99% pure, washed granulocyte suspension of 98% viability can be obtained in 30--40 minutes. The cells prepared by this method displayed higher NBT reduction upon ingesting the same soluble DNA-anti DNA complexes than those prepared by the dextran sedimentation method.

Serum histamine level in exercise-induced bronchospasm.

The changes in serum histamine levels were studied in 12 asthmatic patients: 6 patients gave positive responses and 6 gave negative responses to physical exercise. The serum histamine was determined fluorometrically, and the specific airway conductance was used as the spirometric criteria. The serum histamine levels were elevated in the patients who gave positive responses to exercise.

Measurement of lymphocyte activation by a chromatin topo-optical reaction. Mechanism and specificity of the test.

A rapid inexpensive method is presented for detecting peripheral blood lymphocyte chromatin activation by the neutral red "topo-optical" reaction, which causes strong and easily measurable birefringence in the lymphocyte nuclei. This reaction can be enhanced by fixing the cells with 150 mM/l NaCl in 70% ethanol and/or by treating the unfixed cellular suspensions with 0.2 M/l HCl to remove histones.