Atherosclerosis-inhibiting effect of an antibradykinin agent, pyridinolcarbamate

Anti-proliferative effect of pyridinolcarbamate and of aspirin in the early stages of atherogenesis in swine

When young swine are fed a suitable hyperlipidemic (HL) diet the number of cells in intimal cell masses (ICM) of large and medium-sized arteries begins to increase in number; by 90 days on the diet the cell increase is several-fold compared to no significant increase in cell numbers in ICM of mash-fed controls. The objective of the current study was to see if the cell increase associated with the HL diet could be reduced by pyridinolcarbamate or aspirin. Arteries studied were the abdominal aorta and the coronaries; time on HL diet was 90 days. Both drugs resulted in significant reductions in the increases in cells in ICM associated with the HL diet in both of the arterial beds that were studied. The reduction was most prominent in the abdominal aorta where the increase in ICM cells in the untreated HL diet-fed swine was from an average of 242 +/- 50 cells per cross-section in the mash-fed controls to 1925 +/- 556; in the pyridinolcarbamate-treated swine the increase was only to 641 +/- 214 and in the aspirin-treated group to 770 +/- 146.

Pharmacokinetics and bioavailability of pyridinol carbamate in humans

The pharmacokinetics of two pyridinol carbamate formulations were studied after a single oral administration in 10 healthy volunteers. An open one-compartment model described the evolution of plasma concentrations as a function of time. Pyridinol carbamate was rapidly absorbed (mean lag time from 0.36 to 0.38 hr). Its elimination half-life ranged from 3.3 to 7.9 hr. The two formulations were bioequivalent.

Pyridinolcarbamate and experimental atherosclerosis. Correlation of hypocholesterolemic and antiatherogenic effects

Rabbits were maintained for 12 weeks on either a control or hypercholesteremic dietary regime, or on comparable diets supplemented with pyridinolcarbamate (PDC) at a level of 30 mg/kg body weight/day. Blood was obtained from all rabbits prior to study and at two-week intervals for analysis of serum cholesterol, phospholipid phosphorus and triglycerides. Animals from each group were sacrificed at 4-week intervals for quantitative assessment of the degree of atherosclerotic involvement of the aorta. All animals in the four groups consumed their entire daily allowance (100 g) of their respective diets, and weight gains throughout the feeding period were comparable in the 4 groups. PDC given with the control chow diet had no effect on serum cholesterol levels but did result in persistent decrease in serum triglycerides and a variable decrease in serum phospholipids during the 12-week feeding period. None of the rabbits on the chow diet, with or without PDC, had any evidence of aortic lesions during the experimental period. Rabbits fed 1% cholesterol administered with chow exhibited markedly elevated levels of serum cholesterol and phospholipids, while serum triglycerides were not significantly different than in the control group. In these animals there was a rapid and progressive increase in aortic atherosclerosis throughout the study, and at 12 weeks plaque involvement was 74 +/- 8% of the aortic surface. Addition of PDC to the 1% cholesterol--chow diet resulted in significantly lowered levels of serum cholesterol and phospholipids, but these remained elevated compared to the control levels. There was also a dramatic reduction in the rate and extent of aortic plaque formation. Thus, after 12 weeks on diet, only 27 +/- 6% of the aortic surface showed evidence of atheroma. The data suggest that PDC significantly decreases the hypercholesteremia resulting from feeding 1% cholesterol to rabbits, and that this may be largely responsible for the antiatherogenic effect of this drug.