Ultrastructural manifestation of pharmacologic inhibition of the activities of lipases and proteases in the cat carotid body.

This study is based on the premise that if a subcellular element of an organ performs an appreciable functional role, then its inhibition could influence the ultrastructural organization of the organ. We addressed this issue in the investigation on the carotid body, a chemosensory organ, by comparing the ultrastructure of its parenchyma in phenylmethylsulfonyl fluoride (PMSF)-injected cat with that of the normal cat. PMSF, an inhibitor of lipases and proteases, induced degenerative changes chiefly in subcellular components other than the neurosecretory and synaptic elements being associated with signal transduction. The study suggests that the inhibited enzymes might also have to do with the carotid body function.