[Changes in lipid status during pravastatin treatment]. / Modificazioni del quadro lipidico durante trattamento con pravastatina.

Reduced cholesterolemia lowers the risk of ischemic cardiopathy, especially if LDL cholesterol levels are reduced. Today this effect can be achieved using drugs following the discovery of a new class of molecules: statins are specific inhibitors of HMG-CoA-reductase, a key enzyme in cholesterol biosynthesis. These molecules act by modifying the intracellular quota of cholesterol, especially at a hepatocytic level, thus enabling an enhanced expression of those genes responsible for forming receptors for membrane LDL with an increased number of receptors. This leads to a modulation of receptor activity which interferes with LDL uptake, promoting more rapid clearance. The aim of this study was to confirm the efficacy and tolerability of pravastatin when used for long periods in patients with high cholesterol levels, and to compare its activity to that of gemfibrozil.

[Evaluation of the efficacy and safety of pravastatin in primary hypercholesterolemia]. / Valutazione dell'efficacia e della sicurezza della pravastatina nelle ipercolesterolemie primitive.

Hypercholesterolemia can be a risk factor which engenders coronary heart disease. Today, it seems certain that lowering the cholesterolemia reduces this risk, especially if this reduction is referred to the cholesterol which is linked to the low density lipoprotein, called LDL. It has been demonstrated that the principle way to remove the LDL is by getting it into the hepatocyte through a specific membrane receptor, the research, therefore, has been developed with the aim of pharmacologically modifying the quota of intercellular cholesterol and consequently, in the modulation of the receptivity function by the interference of the LDL uptake, assisting a faster clearance. We can identify a new class of pharmacological drugs, that are the specific inhibitors of the HMGCoA reductase, fundamental enzime in the biosynthesis of cholesterol. This group of inhibitors has recently been enriched by the addition of a new molecule pravastatin. Our task has been to confirm the effectiveness and tolerability of pravastatin, administered for a prolonged period to patients with high levels of cholesterolemia; we have compared it with gemfibrozil, a well-known medicine which has hypocholesterolemic effects. In conclusion, our work, whilst emphasising the expediency of ipolipidic treatment, has undoubtedly proved, that 40 mg of pravastatin in a single evening dose, shows a high degree of efficiency, without side effects. Due to these factors, we can also say that pravastatin prevents, or really induces the regression, of atheroscherotic disease.

Effect of indobufen on whole blood platelet aggregation recorded in the morning in patients with ischaemic heart disease.

Platelets are involved in the progression of coronary atherosclerosis as well as in the development of the acute precipitating event. Recently, it has been shown that normal subjects present increased platelet aggregation between 6.00 a.m. and 9.00 a.m.; epidemiological studies have shown a higher incidence of myocardial infarction between these times. This study evaluated, by an impedence method using whole blood, platelet aggregation induced by ADP (3 microM) and collagen (2 microM/ml). Measurements were made at 6.00 a.m., 9.00 a.m. and 12.00 noon, the day before and the day after evening administration of 200 mg indobufen, a platelet aggregation inhibitor, in 12 patients with ischaemic heart disease. Patients showed a significant increase of platelet aggregation between 6.00 a.m. and 9.00 a.m. which was inhibited by the prior evening administration of indobufen.

[Platelet aggregation in whole blood with the impedance method in subjects with non-complicated essential arterial hypertension]. / L'aggregazione piastrinica su sangue intero con metodo impedenzometrico nei soggetti portatori di ipertensione arteriosa essenziale non complicata.

Arterial hypertension is considered a major risk factor in atherosclerosis in the pathogenesis of which platelet activity plays a fundamental role. However the data in the literature on platelet function in arterial hypertension do not always agree. The present study was conducted on whole blood, using the impedance metering technique to assess platelet aggregation induced by ADP (10 pg) and collagen (2 mg/ml) in 15 patients with uncomplicated essential hypertension and 25 healthy controls. Analysis of the data shows a statistically significant difference between the aggregation curves of the hypertensive and the healthy subjects with excessive platelet aggregation in those suffering from uncomplicated arterial hypertension.

[Platelet aggregation in whole blood and prostacyclin in hyperlipemia types II and IV]. / Aggregazione piastrinica su sangue intero e prostaciclina nelle iperlipemie di tipo II e IV.

Platelets play an essential role in the pathogenesis of atherosclerosis. Prostacyclin is a strong physiological inhibitor of platelets aggregation; prostacyclin indeed is involved in the regulation of platelet interactions with vessel walls and is considered to play a major role in the homeostatic balance. The impedance aggregometry allows the evaluation of platelet aggregation in whole blood. We valued platelet aggregation in whole blood induced by ADP (10 microM) in 40 healthy subjects and in 40 type II and type IV hyperlipemic subjects. Meanwhile by radioimmunoassay we dosed 6-keto PGF1 alpha, a stable product of prostacyclin, in 7 healthy subjects and in 33 hyperlipemic subjects. The statistical investigation put in evidence that at higher plasmatic levels of cholesterol, triglycerides and LDL correspond a greater platelet sensitivity to the aggregating agent, while the opposite happens to higher levels of HDL. The dosage of 6-keto PGF1 alpha put in evidence an increase of this substance in hyperlipemic as to healthy subjects, probably as an answer to augmented platelet aggregation.

[Platelet aggregation in whole blood and thromboxane B2 in type II and IV hyperlipidemia]. / Aggregazione piastrinica su sangue intero e trombossano B2 nelle iperlipemie di tipo II e IV.

Platelets play an essential role in the pathogenesis of atherosclerosis; by impedance method we valued in whole blood platelet aggregation induced by collagen in 40 healthy subjects and in 40 type II and type IV hyperlipemic subjects. Meanwhile by radioimmunoassay we dosed thromboxane B2, a stable product of thromboxane A2, released by platelets during activation, in 7 healthy subjects and 25 hyperlipemic subjects. The statistical investigation put in evidence that at higher plasmatic levels of cholesterol, triglycerides and LDL correspond a greater platelet sensitivity to the aggregating agent, while the opposite happens to higher levels of HDL. The dosage of thromboxane B2 put in evidence a moderate increase in hyperlipemic as to healthy subjects, probably pointing to a state of platelet activity.

[Blood, plasma, erythrocyte viscosity and index of erythrocyte filtration in subjects with hyperlipemia]. / La viscosità ematica, plasmatica, eritrocitaria e l'indice di filtrazione eritrocitario in soggetti affetti da iperlipemia.

40 hyperlipidaemic patients (26 type II a and b, 14 type IV) and 50 healthy controls were studied. The patients were not suffering from any other pathology of note and were under no drug treatment. Blood viscosity at natural Ht and at Ht 45% and plasma viscosity were measured. Red blood cell viscosity and deformability was studied on washed red cells, poor in leucocytes and platelets and suspended in a saline phosphate buffer. The patients with hyperlipidaemia had blood viscosity higher than healthy people. Red blood cell and plasma viscosity were higher in subjects with hyperlipidaemia. There was no difference in the filtration index between the people under study. The increased blood viscosity found in people with hyperlipidaemia appears to be attributable to changes in both the plasma and the erythrocytes.