The Influence of Cholinesterase Inhibitors on the Lipolytic Activity of Rat Aorta

Abstract

1. The normal lipolytic activity (LA) of rat aorta shows considerable individual, age, and sex differences. 2. LA was determined by release of non-esterified fatty acids (NEFA) from lipaemic human serum. 3. Addition of eserine in concentrations inhibitory only to cholinesterases results in approximately 50 % inhibition of LA. 4. Low concentrations of tetra isopropylpyrophosphoramide (iso-OMPA) produced a mean inhibition of 93 %. Up to 100 % inhibition occurred in individual cases. 5. These results suggest that at least 50 % LA of rat aorta depends on non-specific cholinesterase (ChE) and the remainder possibly on an eserine-resistant, iso-OMPA- sensitive aliesterase. 6. Administration of iso-OMPA to living animals produced a fall in plasma NEFA and a reduced aortic LA (to 30 % of normal). ChE activity in cold microtome sections of aorta was completely inhibited. 7. Since no clinical or morphological changes could be observed in the iso-OMPA treated animals, its long term administration is apparently perfectly feasible.