[Tissue and regional distribution of activity of phenylmethylsulfonyl fluoride inhibited carboxypeptidase and other carboxypeptidases in rats].

Phenylmethylsulfonyl fluoride (PMSF)-inhibited carboxypeptidase (CP) is recently described exopeptidase, that cleaved arginine residues from C-terminal of enkephalin synthetic analogs. The highest enzyme activity was found in the adrenal gland and 40% lower one was revealed in the pituitary gland. A 2.5-fold lower than PMSF-inhibited CP activity in adrenal glands was present in testes. The enzyme activity in the brain regions, liver and spleen was about 2.3-fold lower than in the pituitary gland. Its activity in kidneys is insignificant. In the brain region the lowest PMSF-inhibited CP activity was observed in hippocamp and optic and auditory hills, the highest enzyme activity, in the olfactory bulbus and cerebral hemispheres. The differences between brain regions with the highest and the lowest PMSF-inhibited CP activity do not exceed 1.5 fold. The tissue and regional distribution of PMSF-inhibited CP correlated with that for CPH, enzyme of regulatory peptides processing, and it did not correlate with the distribution of lysosomal CPB. The results allow one to suggest the involvement of PMSF-inhibited CP in the processing of the precursors of biological active peptides and secretory proteins. The differences of distribution of PMSF-inhibited CP and CPH are probably connected with involvements of these enzymes in the processing of precursors of different regulatory peptides.