Plasma kinetics of a chylomicron-like emulsion in patients with coronary artery disease.

Chylomicron catabolism in the bloodstream consists of lipolysis by lipoprotein lipase and uptake of remnants by the liver. In rats, triglyceride-rich emulsions can mimic chylomicron metabolism. To further validate this model in man, the emulsion was injected intravenously into fasting and into subjects previously fed a test fatty meal. The plasma kinetic curves of the emulsion 3H-triglyceride and 14C-cholesteryl ester were determined. The fractional clearance rate (FCR) of both labels was markedly reduced in the fed subjects (triglycerides: fed = 0.018 +/- 0.007; fasting = 0.105 +/- 0.013 min-1, P < 0.001; cholesteryl ester: fed = 0.016 +/- 0.001; fasting = 0.040 +/- 0.006 min-1; P < 0.05) indicating that the emulsion and chylomicrons generated from the testinal lipid absorption compete for the same catabolic processes, confirming the validity of the method. The emulsion was injected into 11 patients with CAD and into 11 controls. All had plasma cholesterol < 240 and triglycerides < 250 mg/dl. FCR of triglycerides was 5-fold smaller in CAD compared to controls (0.028 +/- 0.004 and 0.141 +/- 0.069 min-1, respectively, P < 0.01). FCR of cholesteryl ester was 4-fold smaller in CAD than in controls (0.015 +/- 0.004 and 0.056 +/- 0.067 min-1 respectively, P < 0.05). These results indicate that both chylomicron lipolysis and remnant removal are diminished in CAD.

[Pravastatin effects on lipoproteins, Lp (a), apo B and apo A-1 in patients with primary hypercholesterolemia]. / Efeitos da pravastatina nas lipoproteínas, Lp(a), apo B e apo A-I em pacientes com hipercolesterolemia primária.

PURPOSE: To evaluate the effects of pravastatin on lipoproteins, Lp (a), apo B and apo A-I and its tolerability in primary hypercholesterolemic patients in our outpatient lipid clinic. METHODS: Twenty-two primary hypercholesterolemic patients were evaluated. They had all been treated previously with other hypocholesterolemic drugs, including the statins, forming a specific and homogeneous group with hypercholesterolemia and definite coronary risk. After 7 weeks with American Heart Association phase I diet and placebo drug, pravastatin was administered during 12 weeks. All patients received an initial daily dose of 10 mg for six weeks. After this period, this dose was increased to 20 mg. The levels of cholesterol, triglycerides, high-density lipoprotein, lipoprotein (a) and apolipoproteins A-1 and B were determined. RESULTS: No changes occurred with diet and placebo, but pravastatin at a daily dose of 10 mg, reduced significantly cholesterol level (7.22%), LDL-cholesterol (13.08%) and increased HDL-cholesterol (7.81%). The results were better with 20 mg, achieving a reduction of (28.21%) in cholesterol, (36.88%) in LDL-cholesterol, (17.06%) in apo B level and an increase of (10.06%) in HDL-cholesterol. The smaller effect observed with the more commonly used dosage (10 mg/day) was most probably due to the characteristics of the sample with already established hypercholesterolemia, being thus dependent of higher concentrations of medications, as observed in previous treatments in our outpatient clinic. Side affects with this drug were rare. No biochemical changes were observed that would interrupt the continuation of therapy. CONCLUSION: Pravastatin was well tolerated and promoted favorable changes in the total cholesterol, LDL, apo B and cholesterol/HDL and LDL/HDL ratios of primary hypercholesterolemic patients.

Effects of indoramin and metoprolol on plasma lipids and lipoproteins.

The effects of indoramin (n = 29) and metoprolol (n = 15) on lipid profiles in hypertensive patients were compared in a double-blind study. Blood samples were taken at baseline, weeks 3 and 4 of placebo administration, and after 4 and 8 weeks of active treatment. The following assays were performed: total cholesterol, total triglycerides, high density lipoprotein (HDL) cholesterol, HDL3 cholesterol, and apoproteins A, AI, and B. The following values were calculated: HDL2 cholesterol, low density lipoprotein (LDL) cholesterol, total cholesterol/HDL cholesterol ratio (Castelli risk ratio I), and LDL cholesterol/HDL cholesterol (Castelli risk ratio II). The results of an overall analysis showed the following significant changes (mean +/- SD) for indoramin: LDL cholesterol, from 129.50 +/- 38.29 to 114.00 +/- 32.41 mg/dl (p less than or equal to 0.001); apoprotein A, from 169.51 +/- 39.83 to 232.48 +/- 34.08 mg/dl (p less than or equal to 0.001); apoprotein AI, from 105.62 +/- 20.70 to 134.68 +/- 21.58 mg/dl; apoprotein B, from 110.13 +/- 34.88 to 122.34 +/- 32.13 mg/dl (p less than or equal to 0.05); and Castelli risk ratio II, from 2.38 to 1.96 (p less than or equal to 0.01). The following significant variations occurred for metoprolol: total cholesterol, from 201.54 +/- 49.21 to 191.80 +/- 51.88 mg/dl (p less than or equal to 0.05); apoprotein A, from 186.78 +/- 62.63 to 227.68 +/- 44.78 mg/dl (p less than or equal to 0.001); apoprotein AI, from 109.12 +/- 34.72 to 131.95 +/- 21.79 mg/dl (p less than or equal to 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Critical study of lactic dehydrogenase isoenzymes by electrophoresis in the diagnosis of cardiac patients.

Com o objetivo de estudar os padroes de perfis das isoenzimas do LD por fracionamento eletroforetico, os autores relacionaram um grupo normal controle e um grupo de pacientes na fase aguda do infarto do miocardio e com sindrome intermediaria.Para cada patologia foram determinados os padroes de liberacao do LD e HBD a fim de correlaciona-los com a curva de liberacao enzimatica do LD1. A inversao do LD (LD1 > LD2) foi estudada no seu "real significado" com dado diagnostico laboratorial, quando correlacionada a interpretacao clinica (foram usados valores referencia, segundo Galen, para este proposito). Seu valor preditivo pode ser de grande valia para o clinico, porem, o uso deste dado isoladamente pode levar a conclusoes erroneas em pacientes infartados agudos e com sindrome intermediaria. A correlacao entre LD 1 e o HBD foi positiva e se discute sua aplicabilidade sao calculados com base em valores referencia tanto para pacientes na fase aguda do infarto do miocardio, quanto da sindrome intermediaria