Effect of cotrimoxazole (Bactrim) on cholesterol metabolism.

Male albino rats when treated with antimicrobial cotrimoxazole (trimethoprim+sulphamethaoxazole) showed an elevation of plasma high density lipoprotein (HDL) cholesterol and lecithin cholesterol acyl transferase activity (LCAT). Very low density lipoprotein and low density lipoprotein (VLDL+S4, 5LDL) cholesterol levels were decreased. However, total blood cholesterol and aortic cholesterol levels were normal. There was decreased synthesis of cholesterol and its content in the liver. Intestinal cholesterol mobilisation (studied using [U-14C]glucose) towards lymph was normal in spite of decreased synthesis by intestines. Decreased fecal excretion of bile acids and neutral sterols and normal intestinal contribution may be mainly involved in the blood cholesterol homeostasis.

Study of plasma lipids, lipoproteins and lecithin cholesterol acyl transferase activity in nephrotic syndrome

Thirty subjects were included in this study and divided into 2 groups, control [n = 10] and nephrotic [n = 20] group, which further subdivided into 2 subgroups, severe [n = 8, serum albumin below 2 g/dl] and less severe [n = 12, serum albumin above 2 g/dl] nephrotic subgroup. The estimation of plasma level of high density lipoprotein-cholesterol [HDL-C], low density lipoprotein-cholesterol [LDL-C], triglycerides; total cholesterol [TC], free cholesterol [FC], esterified cholesterol [EC], Lecithin cholestero acyl transferase [LCAT] activity, Apolipoprotein-A[1] [APo-A[1]] and other routine investigation were done for all subjects. This study aimed at elucidating the possible changes in LCAT activity, associated with nephrotic syndrome and to find out its relation with plasma lipid and lipoprotein abnormalities in a trial to identify which type of patients are more liable to atherosclerosis. A significant decrease in plasma LCAT activity, APo-A, HDL-C and EC/TC ratio were detected in nephrotic as compared with control group and in severe as compared with less severe nephrotic subgroup. Also, plasma TC, FC, Triglycerides and LDL-C in nephrotic group were significantly higher than control group and FC/TC ratio was higher in severe as compared with less severe nephrotic subgroup. We conclude that low HDL-C and its APo-A[1] level along with. low LCAT activity may uncover the protection of nephrotic patients against enhanced atherogenesis and the low serum albumin level as well as the higher FC/TC ratio may predict the patients more prone to atherogenesis

Relationship between lecithin: cholesterol acyltransfer and lipid and lipoprotein levels in plasma of mammals susceptible or resistant to atherosclerosis

The initial fractional and molar rates of lecithin:cholesterol acyltransfer and the plasma concentrations of unesterified and esterified cholesterol, total phospholipids, triacylglycerol, high density lipoprotein-cholesterol and aplipoprotein B-linked cholesterol were determined for young healthy women and for groups of female pigs, rabbits, rats and cattle. Coefficients were calculated for the simple and partial correlations between acyltransfer rates and lipid and lipoprotein concentrations. In all species molar acyltransfer rates were significantly corrlated with unesterified cholesterol levels. For women, pigs and rabbits (atherosclerosis-susceptible species) acyltransfer rate was significantly correlated with triacylglycerol and apolipoprotein B-linked cholesterol levels, but not with high desnity lipoprotein-cholesterol. In contrast, acyltransfer rates for rats and bovines (atherosclerosis-resistant species) were significantly correlated with high density lipoprotein-cholesterol, but not with the other parameters. These results, together with the corresponding partial correlation analyses, suggest significant functional differences for lecithin:cholesterol acyltransfer in atherosclerosis-resistant and athrosclerosis-susceptible species and that in the latter group, this enzyme may be mainly invilved in the disposal of cholesterol from triacylglycerol-rich lipo-proteins rather than in removing excess tissue cholesterol for transport to the liver