Effects of acetylsalicylic acid on plasma lipids and on post-heparin lipase activities

Acetylsalicylic acid (ASA) was administered orally at the dose of 3 g a day for 2 days to healthy subjects. Plasma free fatty acids, serum triglycerides and prebetalipoproteins were significantly decreased, while cholesterol, beta and alpha 1 lipoproteins did not change. The two fractions (protamine-resistant and protamine-inactivated) of plasma post-heparin lipoprotein lipase activity (PHLA) significantly fell after ASA. PHLA diminution was reproduced by direct addition of ASA or sodium salicylate or of plasma from individuals under treatment with ASA to post-heparin plasma of untreated subjects and is, therefore, explained by a direct inactivation. The inhibition of PHLA was not followed by a significant impairment of the removal of circulating triglycerides.

Influence of two non-steroidal anti-inflammatory drugs on lipolysis and on plasma post-heparin lipoprotein lipase activity in normal man

Indomethacin 50 mg i.v. or p.o. and diclofenac sodium 50 mg p.o. produced a prompt and significant increase in plasma free fatty acid concentration. In 10 subjects who took indomethacin 150 mg/d p.o. for 3 days, plasma post-heparin lipoprotein lipase activity was also significantly increased. The same effect occurred in 9 subjects treated for 3 days with diclofenac sodium 50 mg t.d.s. Since both indomethacin and diclofenac sodium are potent inhibitors of prostaglandin synthetase, these findings are consistent with the hypothesis tht prostaglandins are involved in the feed-back regulation of lipolysis, and mediate the inhibitory effect of lipolysis on lipoprotein lipase activity.

Increase in lipolysis and decrease in plasma-heparin lipoprotein lipase activity and alpha 1 lipoprotein level after aminophylline in man

Intravenous aminophylline 0.48 g produced a sharp increase in plasma free fatty acids. After three days of treatment with aminophylline 0.96 g/day i.v., plasma post-heparin lipoprotein lipase was significantly reduced, and post-heparin hepatic triglyceridase remained unchanged. alpha 1 lipoprotein was reduced by treatment, in parallel with lipoprotein lipase, while other lipoprotein fractions, serum cholesterol and triglycerides were unaffected.

Serum lipoproteins in diabetes: relation of alpha-lipoprotein level to therapy

Three hundred and sixty diabetic patients (125 on insulin, 109 on sulfonylureas and 126 on diet alone) were selected to investigate the effect of the type of treatment and of the degree of metabolic control on serum lipoproteins. Prebeta-lipoprotein concentration was higher than normal in all treatment groups. Beta-lipoproteins were significantly higher in diabetic women than in controls. No difference in beta- and prebeta-lipoprotein concentration existed between the 3 treatment groups. Alpha-lipoproteins were significantly higher in insulin-treated than in diet-treated patients irrespective of the degree of metabolic control. The daily dose of insulin and, in patients on diet or sulfonylureas, serum IRI were positively correlated to alpha-lipoprotein concentration while this lipoprotein fraction was not significantly correlated to fasting blood sugar. Alpha-lipoprotein concentration, then, appears to be markedly influenced by exogenous and endogenous insulin, independently of the degree of metabolic control.

Evidence of an effect of inhaled disodium cromoglycate on lipid metabolism in man: enhanced lipolysis and decreased plasma post-heparin lipase activities

Inhalation of therapeutic doses of disodium cromoglycate (DSCG) was followed by a prompt increase of plasma free fatty acids (FFA). After treatment with DSCG for 3 days both hepatic and non-hepatic (lipoprotein lipase sensu strictiori) plasma post-heparin lipoprotein lipase activities were significantly depressed. No significant change was induced on serum lipids and lipoproteins, nor on the fat tolerance curve, though a trend to an elevation of this last parameter was noted. Our results show that the inhalation of DSCG produces systemic metabolic effects, being in accord with the view that this drug raises intracellular cyclic adenosine monophosphate. Furthermore, they support the contention that lipoprotein lipase activity is controlled by intracellular concentration of FFA and/or cyclic adenosine monophosphate.

An evaluation of quantitative agarose-gel electrophoresis of serum lipoproteins

The method of Hatch et al. (Hatch, F.T., Lindgren, F.T., Adamson, G.L., Jensen, L.C. and Wong, A.W. (1973) J. Lab. Clin. Med. 81, 946-960) of quantitative determination of serum lipoproteins has been compared with preparative ultracentrifugation and chemical analysis of the lipoprotein fractions and a good concordance was demonstrated. The replacement of the coefficients proposed by Hatch et al. by the ones derived from the present study does not bring about relevant changes of the results when the harmonic mean of two calibration factors, derived from serum cholesterol and triglycerides, is used, thus indicating that this method of calculation minimizes the effect of variation of the chemical composition of lipoproteins. The method is sufficiently reliable and reproducible for practical pruposes and is recommended as the standard method for the clinical laboratory.

Effect of prostaglandin synthetase inhibitors on renin and aldosterone in man on a normal or low sodium diet

The effect of two inhibitors of prostaglandin synthetase activity (acetylsalicylic acid (ASA) and diclofenac sodium (DCFS)) on plasma renin activity (PRA) and plasma aldosterone (PA) was studied in normal subjects kept on a diet with constant sodium and potassium intake or on a low-salt diet for 7 days.

In 9 subjects, 2 days of treatment with ASA (3 g/day) was followed by a significant decrease of PA in the supine position (after overnight rest); there was no significant decrease of PRA. However, both PA and PRA with the subjects in the upright position were significantly reduced after ASA.

In 9 subjects treated with DCFS (200 mg for 2 days), both PA and PRA with the subjects in the supine and upright positions decreased significantly. Similar results were obtained from 4 subjects on a low-sodium diet (15–30 mEq./day) treated with DCFS (150 mg/day for 3 days).

In contrast, no significant changes in PA or PRA with the subjects in the supine or upright position were observed in 4 subjects on a very low sodium diet (< 15 mEq./day) treated with DCFS (150 mg/day for 3 days). Covariance analysis (with PRA as independent variable and PA as dependent variable) of the data obtained in the upright position before and after treatment with ASA or DCFS showed that the decrease in PA remained significant after adjustment for the PRA effect.

These results suggest a direct effect of prostaglandins on PA. The data obtained from subjects on a low sodium diet indicate that sodium deprivation may counteract the effects of DCFS on PRA and PA.

Low-fat diet versus low-carbohydrate diet in the treatment of type IV hyperlipoproteinaemia

The response to dietary management was studied in 24 hypertriglyceridaemic out-patients. Fourteen patients were kept on a diet low in fat and cholesterol and high in polyunsaturated fatty acids; 10 of these patients subsequently followed a period of low-carbohydrate diet. At the end of the first period a significant decrease of serum triglyceride, cholesterol and beta-lipoproteins was observed; after the second feeding period no substantial change of serum lipoprotein pattern occurred. Ten patients were given a low-carbohydrate diet that produced a significant fall of the levels of triglycerides and pre-beta-lipoproteins. Six of these subjects continued the experiment with the low-fat diet; during this period a further trend toward reduction of serum triglyceride, cholesterol and beta-lipoproteins was observed which, however, was not statistically significant. We conclude that serum triglyceride levels can be lowered both by a low-carbohydrate diet and by a low-fat diet, but the latter has the advantage of also producing a significant fall of serum cholesterol and beta-lipoproteins.