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I Testa

Publications and source records attributed to I Testa.

At least 19 recordsLinked to original sources
PubMed2004

Effect of 4G/5G PAI-1 polymorphism on the response of PAI-1 activity to vitamin E supplementation in Type 2 diabetic patients.

Plasminogen activator inhibitor type 1 (PAI-1) is an independent cardiovascular risk factor and increases in patients with Type 2 diabetes mellitus. The 4G/5G polymorphism of PAI-1 has been reported to be involved in the incidence of cardiovascular disease by regulation of PAI-1 levels, but this relation is still under debate. The aim of the study was to test the effect of 4G/5G polymorphism on the lowering of PAI-1 levels in Type 2 diabetic patients during vitamin E supplementation. Ninety-three Type 2 diabetic subjects (age +/- SD, 62.1 +/- 6.1 yr) were enrolled and treated with vitamin E (500 IU/die) for 10 weeks. We determined the 4G/5G polymorphism and PAI-1 activity at baseline, during (5th and 10th week) and after (30th week) vitamin E supplementation. No significant differences were found in PAI-1 and its determinants among the three genotypic groups at baseline. Decrements were detected in the whole group in PAI-1 at the 5th and the 10th week from baseline followed by an increase at the 30th week (p<0.001). Patients with 4G/4G and 4G/5G genotypes showed a different trend with respect to those with 5G/5G in PAI-1. In particular, there was a decrease in 4G/4G and 4G/5G PAI-1 levels from the 10th week, while a decrease in 5G/5G PAI-1 was observed from the 5th week (p<0.01). The delayed decrease, found in patients with at least one 4G allele with respect to those with 5G/5G genotype, demonstrates that 4G/5G polymorphism mainly influences the rate of decrease of PAI-1 after supplementation with vitamin E in Type 2 diabetic subjects.

Antioxidants↗
PubMed2002

Helicobacter pylori masks differences in homocysteine plasma levels between controls and type 2 diabetic patients.

BACKGROUND: Data in the literature have not clarified whether type 2 diabetes mellitus affects homocysteine plasma levels. Different variables able to influence homocysteine could be the cause of these controversial findings. An important but neglected confounding factor is Helicobacter pylori, which has been demonstrated to be a cause of elevated levels of homocysteine and which is prevalent in the Caucasian population, ranging from 30 to 40% incidence. Starting from these findings we wanted to verify whether differences in homocysteine levels exist between a type 2 diabetic population and a control group, taking into account the presence/absence of Helicobacter pylori. DESIGN: The study was carried out on a group of uncomplicated and normotensive type 2 diabetic patients (n = 30, 55.7 +/- 9.7 years) and on a control group (n = 43, 51.2 +/- 11.3 years). On these subjects we evaluated: main parameters of glyco- and lipo-metabolic balance, presence of Helicobacter pylori by 13C Urea Breath Test, plasma homocysteine, vitamin B12, folate and genetic polymorphism of methylenetetrahydrofolate reductase. RESULTS: Evaluating the two groups as a whole, significant differences in homocysteine were found when considering Helicobacter pylori presence/absence (14.0 +/- 6.5 vs. 10.6 +/- 4.7 micromol L-1, respectively, P < 0.01) without differences of vitamins and the genetic polymorphism of methylenetetrahydrofolate reductase. The positive interaction found among Helicobacter pylori, diabetes and homocysteine (P = 0.03) taking into account all the other evaluated confounding factors, demonstrates that a significant difference in homocysteine plasma levels exists between diabetics and controls (Helicobacter pylori-negative: diabetics 12.5 +/- 5.6 micromol L-1, controls 9.4 +/- 3.8 micromol L-1; Helicobacter pylori-positive: diabetics 13.6 +/- 5.8 micromol L-1, controls 14.3 +/- 7.0 micromol L-1). CONCLUSIONS: Type 2 diabetes seems to induce per se higher levels of homocysteine, which appears to be one of the factors responsible for the increased risk of vascular damage.

Adult↗
PubMed2001

Fast, simple and cost-effective determination of thiopental in human plasma by a new HPLC technique.

BACKGROUND: Thiopental is an anaesthetic drug that is largely used in both short-term and long-term infusion. After long-term infusion of thiopental, non-linear and inter-individual-dependent pharmacokinetics occur because of the saturation and/or induction of the metabolism. Clinical monitoring is important so that therapeutic adjustments can be made in many of the different pharmacological treatments, especially when long-term infusion is required. We describe a new, rapid HPLC method for the determination of plasma thiopental. METHODS: Sample preparation involved precipitation of plasma proteins using a mixture of methanol, zinc sulfate and ethylene glycol, and containing the internal standard 5-ethyl-5-p-tolyl-barbituric acid. After adding trichloroacetic acid, the sample was centrifuged and the supernatant was injected into a C(18) reversed-phase column. The mobile phase used was water-methanol-acetonitrile (50:40:10, v/v). The eluent was monitored at 290 nm. RESULTS: The calibration curve was linear from 0.2 to 100 microg/mL. Precision, calculated as the coefficient of variation (%), was in the range of 3.62-0.70% for the within-day assay and 5.77-1.51% for the between-day assay. The absolute recoveries obtained from supplemented samples were never less than 100%. CONCLUSIONS: This technique shows good reliability and seems to be suitable for a very fast and simple therapeutic monitoring of plasma thiopental.

Anesthetics, Intravenous↗
PubMed2001

Diagnosis of MODY in the offspring of parents with insulin-dependent and non-insulin-dependent diabetes mellitus.

Maturity Onset Diabetes of the Young (MODY) is an autosomal dominant monogenic form of type 2 diabetes mellitus (DM) representing 5% of youth-onset DM in the Caucasian population. In young adults the disease can be present as either non-insulin dependent or insulin-dependent DM. The diagnosis of this genetic disorder in children and adolescents is rare because of the mild glucose metabolism disorder at this time. We performed a metabolic, autoimmune and genetic study in 40 offspring of young parents affected by insulin-dependent DM (Group A) and in 35 offspring of young parents affected by early-onset non-insulin-dependent DM (Group B). Two children of Group A (5%) were found to be affected by fasting hyperglycemia and carry a GCK gene mutation that in one case was present also in the diabetic father. Eighteen offspring of Group B (51%) were positive for GCK or HNF-1alpha gene mutations present in the affected parents. All but two of these young patients had impaired fasting glucose (IFG) or impaired glucose tolerance (IGT). Eleven of them were younger than 16 years. We conclude that screening for DM in youth should be extended to MODY in young families with both non-insulin-dependent and insulin-dependent DM. The sensitivity of the metabolic tests will precede the genetic diagnosis.

Adolescent↗
PubMed2001

Vitamin E intake reduces plasminogen activator inhibitor type 1 in T2DM patients.

Previous studies hypothesised that vitamin E could protect against coronary heart disease and vascular complications in diabetes, but no studies have been performed regarding its eventual effects on fibrinolysis. Nevertheless, in Type 2 diabetes mellitus (T2DM) a profound reduction in the fibrinolytic activity has been demonstrated to be involved in vascular complications, probably due to plasminogen activator inhibitor type 1 (PAI-1) overproduction. On this basis we aimed to verify whether an antioxidant treatment with vitamin E is able to lower PAI-1 plasma levels in T2DM. Thirteen T2DM patients (9 males and 4 females; mean age+/-SD, 64.4+/-3.3 yr) were selected through strict admission criteria. These patients were treated with vitamin E (500 IU/die) for 10 weeks. Glyco-lipometabolic, oxidative and haemocoagulative parameters were evaluated at baseline and after 5, 10, 30 and 60 weeks. Vitamin E levels at different times were [median (interquartile range)] 6.1 (5.3-7.7), 8.5 (7.3-9.9), 9.7 (8.9-12.9), 5.6 (4.4-6.8), 5.7 (4.5-7.1) microg/ml, respectively. Significant differences were found for PAI-1 antigen (p=0.006), PAI-1 activity (p=0.028), apolipoprotein B (p=0.015) and antioxidant defence, evaluated as ferric reducing ability of plasma (FRAP) values (p=0.005). Particularly, decrements were detected for PAI-1 antigen between baseline and the 10th week (p<0.05), followed by an increase back to basal at the 30th week. Similar behaviour was found for PAI-1 activity. Regarding the antioxidant defence, FRAP values increased until the 30th week (p<0.05) with a decrease at the 60th week. These results demonstrate that vitamin E is able to lower PAI-1 levels in diabetic patients but this effect does not seem related to improvements of glycometabolic data or to the increase in FRAP values, suggesting that PAI-1 overproduction can be decreased by other effects of vitamin E on endothelial cells.

Aged↗
PubMed2000

Autoimmune thyroid diseases in patients with undifferentiated connective tissue disease.

Previous data have indicated that organ-specific and non-organ-specific autoimmune diseases may occur in the same patient. We report here our study on the type and prevalence of endocrine autoimmune diseases in undifferentiated connective tissue disease (UCTD). A retrospective analysis revealed five out of 75 UCTD cases (6.6%) with cytology-verified autoimmune thyroiditis (associated with insulin-dependent diabetes mellitus in one case). Other UCTD patients had Graves' disease (one case), non-toxic multinodular goitre (two cases) and central hypothyroidism (one case). In a prospective study, thyroid function was evaluated in 15 consecutive UCTD patients with neither clinical nor laboratory signs of thyroid involvement. Basal and post-TRH stimulation TSH levels were significantly higher in UCTD patients than in healthy subjects.

Adolescent↗
PubMed2000

One- and two-compartment minimal models detect similar alterations of glucose metabolism indexes in hypertension.

A standard intravenous glucose tolerance test (IVGTT) was performed in 10 nondiabetic patients with essential hypertension (H group) and 9 normotensive control subjects (N group). A 2-compartment minimal model (2CMM) of glucose kinetics was applied to estimate indexes of glucose effectiveness, S2G and insulin sensitivity, S2I, by means of a maximum a posteriori (MAP) bayesian estimation technique. These estimates were contrasted to the S1G and S1I indexes provided by the classic minimal model (1CMM). In both the N group and the H group, the 2CMM underestimated the glucose effectiveness and overestimated the insulin sensitivity. In the H group, S2G was, on average, 63% of S1G (P > .05) and S2I was 137% of S1I (P > .05). In the N group S2G was 67% of S1G (P > .05) and S2I was 134% of S1I (P > .05). The 2CMM detected a reduction of approximately 40% (P > .05) and approximately 48% (P > .05) in S2G and S2I estimates, respectively, from the N group to the H group. Despite its reduced complexity, the 1CMM also detected a reduction of approximately 35% (P < .05) and approximately 49% (P < .05) in the S1G and in S1I indexes, respectively. Thus, the 1CMM and 2CMM showed a substantial equivalence in detecting a severe reduction in insulin sensitivity and impaired glucose effectiveness in hypertensive patients compared with normal.

Adult↗
PubMed2000

Fibronectin and lipoprotein(a) are inversely related to plasminogen activator inhibitor type-1 levels in Type 2 diabetic patients without complications.

Plasminogen activator inhibitor type-1 (PAI-1), the most important physiological fibrinolysis inhibitor, is considered an independent factor of cardiovascular risk in Type 2 diabetes mellitus (T2DM). In previous papers we demonstrated that a T2DM population without complications presents: 1) PAI-1 not increased with respect to a control group; and 2) a negative correlation between PAI-1 and lipoprotein(a) [Lp(a)], suggesting that in these subjects PAI-1 levels could be modulated by the "endothelial stress" induced by Lp(a) and diabetes. This work has been performed in order to better verify this intriguing hypothesis, and the endothelial stress has been evaluated through a marker of endothelial damage, fibronectin (FNC). For this purpose we chose a T2DM population without complications (n=73) and a control group (n=46). Plasma concentrations of FNC, Lp(a), PAI-1 antigen and activity, and the main parameters of lipo- and glycometabolic balance were determined. Fibronectin was significantly higher in diabetics with respect to controls (p<0.01). As expected, significant correlation between PAI-1 antigen, PAI-1 activity and Lp(a) (r=-0.54,p<0.01 and r=-0.39,p<0.01, respectively) was found only in diabetic patients. In the same group FNC showed a significant correlation with PAI-1 antigen and activity (r=-0.49,p<0.01 and r=-0.47; p<0.01, respectively), while no relationship was found between Lp(a) and FNC. Multiple regression analysis showed statistically significant correlation between PAI-1 antigen and PAI-1 activity with FNC and Lp(a) in diabetic patients without complications (p<0.05). These data suggest that in absence of complications, the endothelium is able to modulate PAI-1 levels, favouring in that way the fibrinolytic pathway and, subsequently, the recovery of the endothelial integrity. This modulation seems to be related to parameters such as Lp(a) and FNC, although the mechanisms of the endothelial stress of these two molecules seem to be different.

Blood Glucose↗
PubMed1999

Determination of plasma metformin by a new cation-exchange HPLC technique.

Metformin is an oral antihyperglycemic agent used in the therapy of noninsulin-dependent diabetic patients. This biguanide can induce dangerous complications such as lactic acidosis when its plasma concentration is too high. For this reason, the determination of plasma metformin should always be done during treatment. We developed a new HPLC method, for the routine determination of plasma metformin, with good reliability, rapid execution, and low costs. Sample preparation involved precipitation of the plasma proteins containing the internal standard buformin with a mixture of methanol, zinc sulfate, and ethylene glycol; the diluted supernatant was injected into a cation-exchange column. The mobile phase was potassium dihydrogenphosphate buffer-containing acetonitrile. The eluent was monitored at 236 nm. The calibration curve is linear within the range of 20-4000 ng/mL; the within-day coefficients of variation were less than 2.2% for metformin and 1.5% for buformin; the day-to-day coefficients of variation were less than 2.5% for metformin and 1.9% for buformin. The mean recoveries obtained from supplemented samples were included between 99.4 and 104.2% for metformin. Many characteristics make this method useful and easily accessible to all clinical laboratories equipped with HPLC instrumentation.

Administration, Oral↗
PubMed1999

A strong inverse relationship between PAI-1 and Lp(a) in hypertensive Type 2 diabetic patients.

Thrombophilia with a contemporary reduction of fibrinolytic activity has been observed both in diabetes mellitus and hypertension. Previously, we found a relationship between plasminogen activator inhibitor Type 1 (PAI-1) and lipoprotein(a) [Lp(a)] in Type 2 diabetes mellitus patients without complications. We hypothesised that this relationship could be due to a compensatory mechanism able to lower the risk of hypofibrinolysis as found in Type 2 diabetes mellitus. The present work was aimed at investigating the influence of concurrent hypertension and diabetes mellitus on the plasma levels of these two fibrinolytic inhibitors. In addition, other risk factors, known to influence the fibrinolytic parameters, were taken into account. Forty-nine Type 2 nonhypertensive diabetic patients without complications, 47 Type 2 hypertensive diabetic patients without complications, 54 non-diabetic hypertensive subjects without complications as well as 87 control subjects were studied. Plasma concentrations of Lp(a), PAI-1 antigen and activity, and the main parameters of oxidative, lipo- and glycometabolic balance were determined. Significant statistical differences between diabetic and non-diabetic subjects were found concerning triglycerides and antioxidant defence (p<0.01). Analysis of variance showed the F test statistically significant in evaluating the Log PAI-1/Lp(a) (p = 0.02). Correlation analysis between Log PAI-1 antigen and Lp(a) was significant in non-hypertensive diabetic patients, as expected (r = -0.38, p<0.01), and even stronger in hypertensive diabetic patients (r = -O.72,p<0.01). These results allow to hypothesise that the relationship between PAI-1/Lp(a) could be determinant in avoiding vascular complications due to diabetes mellitus and hypertension.

Aged↗
PubMed1998

A significant relationship between plasminogen activator inhibitor type-1 and lipoprotein(a) in non-insulin-dependent diabetes mellitus without complications.

We previously found a relationship between plasminogen activator inhibitor type-1 and lipoprotein(a) in non-insulin-dependent diabetes mellitus and hypothesized that this could be due to a compensatory mechanism able to lower the risk of hypofibrinolysis found in type II diabetes mellitus. The aims of the present study were: (1) to confirm the association between plasminogen activator inhibitor type-1 and lipoprotein(a) in a different group of non-insulin-dependent diabetes mellitus patients and (2) to investigate whether the association could be related to diabetic complications. Other vascular risk factors able to influence fibrinolytic parameters such as glycemia, obesity, hypertension, dyslipidemia, and oxidative stress were also considered. Sixty-six non-insulin-dependent diabetes mellitus patients without diabetic complications (48 men, 18 women), 45 non-insulin-dependent diabetes mellitus patients with complications (21 men, 24 women), and 31 control subjects (17 men, 14 women) were studied. Plasma concentrations of lipoprotein(a), plasminogen activator inhibitor type-1 antigen and activity, and the main parameters of lipo- and glycometabolic balance were determined. Antioxidant defense was assayed as oxygen radical absorbance capacity of serum. Statistically significant differences among controls and the two diabetic groups were found for fasting glucose, cholesterol, triglycerides, and oxygen radical absorbance capacity of serum, while no statistically significant differences were evident for plasminogen activator inhibitor type-1 antigen and activity and lipoprotein(a). Regression analysis of log plasminogen activator inhibitor type-1/lipoprotein(a) showed a significant correlation only in diabetic patients without complications (r = -0.57, P < 0.001). These results show that a relationship between plasminogen activator inhibitor type-1 and lipoprotein(a) is characteristic of a diabetic population without complications, supporting the suggestion that this relationship could be a compensatory mechanism of the fibrinolytic system to limit the risks of hypofibrinolysis. A lack or a loss of capacity to balance lipoprotein(a) and plasminogen activator inhibitor type-1 could contribute to the pathogenesis of the diabetic complications.

Adult↗
PubMed1997

Determination of vanillylmandelic, 5-hydroxyindoleacetic and homovanillic acid in urine by isocratic liquid chromatography.

A new isocratic HPLC method, employing electrochemical detection, is described for the determination of urinary vanillylmandelic acid, 5-hydroxyindoleacetic acid and homovanillic acid. The main advantages of this technique are: simplicity, simultaneous determination of all analytes, the absence of an extraction procedure, isocratic elution and low cost. The diluted urine is injected onto a C18 reversed phase column. The mobile phase is potassium dihydrogenphosphate buffer containing 1-heptanesulphonic acid, methanol and acetonitrile. The calibration curves are linear from 0.1 to 50 mg/l; the precision data show CV less than 2.36% for within-day assay and less than 2.72% for day-to-day assays. The mean recoveries for supplemented samples are 98.2 to 102.0% for vanillylmandelic acid, 99.6 to 103.9% for 5-hydroxyindoleacetic acid and 98.7 to 102.0% for homovanillic acid. In comparisons of the present method with Radjaipur's extraction method (Radjaipur M. et al., Eur J Clin Chem Clin Biochem 1994; 32:609-13) the slopes for the three analytes were nearly 1, and the confidence region of the intercepts was close to 0. In conclusion the technique seems to be suitable for routine determination of the three analytes, especially for mass screening purposes.

Adult↗
PubMed1996

Glycosylated hemoglobin and fructosamines: does their determination really reflect the glycemic control in diabetic patients?

The present experiment was designed to determine whether scavenging capacity of serum, in addition to glucose level, influences hemoglobin and serum protein glycosylation in non-insulin dependent diabetic patients. For this purpose forty-seven patients homogeneous for age, disease duration, therapy and glyco-metabolic control were selected. Fasting and post-prandial glycemia and insulinemia as well as glycosuria were weekly analysed during the sixty days preceding glycosylated hemoglobin (HbA1c), fructosamines and serum scavenging capacity determination. This last parameter has been evaluated by a method based on the property of beta-phycoerythrin (beta-PE) to loss its fluorescence when damaged by oxygen radicals, that were produced by Cu++ and H2O2. The oxygen radical absorbance capacity (ORACOH) of serum was assayed as the ability of serum to delay the loss of beta-PE fluorescence. As expected, a statistically significant positive correlation was found comparing both fructosamines and HbA1c levels with mean fasting glycemia measured over twenty and sixty days, respectively. The key result of this study is represented by the finding that both HbAlc and fructosamines levels show a statistically significant negative correlation with ORACOH values. This correlation can explain a large percent of the data dispersion occurring when ORACOH is not taken into account. In order to better describe the role of ORACOH, patients were separated into two sub-groups with an ORACOH lower (L-ORACOH) and greater (H-ORACOH) than 100 U/ml. Examining the correlation between mean fasting glycemia and the two glycosylated proteins considered in these two sub-groups, curves with different slopes were obtained, supporting that the rate of glycosylation of both proteins was higher in L-ORACOH patients as compared to those with H-ORACOH. Present data suggest that for a proper interpretation of the HbA1c and fructosamines data in diabetic patients, the scavenging capacity level of serum should be taken into account.

Aged↗
PubMed1996

Relationship between plasminogen activator inhibitor type-1 plasma levels and the lipoprotein(a) concentrations in non-insulin-dependent diabetes mellitus.

The first part of the paper deals with the relationship between two inhibiting factors of the complex enzyme cascade regulating fibrinolysis, namely plasminogen activator inhibitor type-1 (PAI-1) and lipoprotein(a) (Lp(a)). Blood concentrations of Lp(a), PAI-1 antigen (PAI-1 AG) and activity (PAI-1 AT), and the main parameters of lipo- and glyco-metabolic balance were studied in 80 type II diabetic patients. Roughly hyperbolic patterns have been found between PAI-1 and Lp(a). Negative statistically significant linear correlation can be elicited when Log PAI-1 AG and Log PAI-1 AT values are plotted versus Lp(a) values, the first one being particularly tight. These findings suggest a nearly on/off control of the two parameters, limiting the risk of hypofibrinolysis. The second part of the paper was aimed at verifying this hypothesis. A group of 30 diabetic patients were treated for 3 months with metformin, an antidiabetic biguanide compound which has been reported to reduce PAI-1 levels both in diabetic and in non-diabetic patients. Metformin significantly reduced PAI-1 AG and PAI-1 AT but did not influence plasma Lp(a) levels. A clear linear correlation between the basal Lp(a) values and the changes in PAI-1 AG levels was found. An even tighter correlation was elicited between the decrease in PAI-1, and PAI-1 pretreatment values.

Aged↗
PubMed1996

Is metformin safe enough for ageing type 2 diabetic patients?

We assessed the effect of adding low doses of metformin to sulfonylurea therapy in 76 elderly Type 2 diabetic patients by monitoring glycaemic control and blood lactate for one year. Metformin markedly improved glycaemic control. Fasting lactate concentrations were not affected and post-meal lactate peaks were minimally increased. Additional benefits included an improvement in some lipid parameters, a reduction in serum uric acid and a significant weight loss in overweight patients. Metformin was clinically well-tolerated. Instead of advanced age alone, renal function and/or any other age-related factor likely to contribute to lactate overproduction should be the basis for deciding on metformin therapy. No evidence indicated that metformin should be denied "a priori" to ageing Type 2 diabetic patients.

Aged↗
PubMed1995

[Treatment of hyperlipidemia in obese patients: monotherapy versus bi-therapy].

OBJECTIVES: Severe hyperlipoproteinaemia (increased LDL, light density lipoproteins, and VLDL, very light density lipoproteins) in patients with high body mass index (BMI) is positively associated with the occurrence of coronary heart disease. This condition requires combined drug regimen because high lipid levels frequently remain after monotherapy and diet. The aim of our study was to investigate the efficacy of combined therapy utilizing the following association: HMG CoA reductase inhibitors plus fibrates. METHODS: We examined 50 patients, males, affected by obesity (BMI > 30) and hyperlipoproteinaemia (phenotype IIB, Fredrickson). The first group, 20 obese subjects with severe dislipidaemia, and the second group, 10 mildly hyperlipidaemic obese patients received bezafibrate 600 mg/d and pravastatin 40 mg/d. The other subjects, all obese and highly dyslipidaemic patients, received monotherapy: 10 patients, bezafibrate 600 mg/d and the rest pravastatin 40 mg/d. Weekly, for ten weeks, we evaluated the following serum parameters: total cholesterol and HDL-cholesterol, triglycerides and apolipoprotein A1 and B. RESULTS: We observed no significant changes in HDL-cholesterol and apolipoprotein levels, while an important reduction in total cholesterol and triglycerides, induced by combined therapy, was particularly evident in those patients with the higher lipidic alterations, compared with the additive effects of single drugs. CONCLUSIONS: The data show that this combined treatment could be proposed for these subjects to reduce hyperlipidaemia and the risk of premature atherosclerosis.

Adult↗
PubMed1993

Effect of hydroxymethylglutaryl-CoA reductase inhibitors on the functional properties of erythrocyte membranes.

We studied 56 patients affected by primary hypercholesterolemia treated with placebo for 1 month and with simvastatin (20 mg/day) or pravastatin (20 mg/day) for 6 months during a double-blind clinical trial. At 1-month intervals we determined the following parameters in the serum: total and HDL cholesterol, triglycerides, and apolipoprotein A-1 and B. At the same time intervals we also determined the cholesterol and phospholipid concentration, the Na+/K+ ATPase activity, and the fluidity of erythrocyte membranes. Our results demonstrated the following modifications in the erythrocyte membranes during simvastatin and pravastatin treatments: (1) an initial increase in cholesterol concentration and in cholesterol/phospholipid molar ratio, with a significant decrease only after 4 months; (2) a similar behavior of membrane fluidity, with an initial decrease and an elevation after 4 months; (3) an increase in the Na+/K+ ATPase activity only after 4 months. We hypothesize that simvastatin and pravastatin not only inhibit the hepatic synthesis of cholesterol, but also modify the cholesterol exchange between plasma and the erythrocyte membrane.

Adolescent↗