Search results for "Cytochrome"
showing 10 items of 607 documents
Mechanisms underlying recoupling of eNOS by HMG-CoA reductase inhibition in a rat model of streptozotocin-induced diabetes mellitus
2007
Abstract Objective HMG-CoA reductase inhibitors have been shown to upregulate GTP cyclohydrolase I (GTPCH-I), the key enzyme for tetrahydrobiopterin de novo synthesis and to normalize tetrahydrobiopterin levels in hyperglycemic endothelial cells. We sought to determine whether in vivo treatment with the HMG-CoA reductase inhibitor atorvastatin is able to upregulate the GTPCH-I, to recouple eNOS and to normalize endothelial dysfunction in an experimental model of diabetes mellitus. Methods and results In male Wistar rats, diabetes was induced by streptozotocin (STZ, 60mg/kg). In STZ rats, atorvastatin feeding (20mg/kg/d, 7 weeks), normalized vascular dysfunction as analyzed by isometric tens…
Response of genetically obese Zucker rats to ciprofibrate, a hypolipidemic agent, with peroxisome proliferation activity as compared to Zucker lean a…
1993
Genetically obese Zucker (fa/fa) rats were used as an experimental model to study the effects of hypolipidemic agents on peroxisome proliferation; comparison was made with Zucker lean phenotype (Fa/-) and Sprague-Dawley strain/phenotype. The pharmacokinetics of a single administration of ciprofibrate (1 or 3 mg/kg), appeared to be similar in all strains/phenotypes. After a 2-week oral administration at the same dosages, there were dosage-related increases in hepatocellular peroxisomal yield and in the hepatic enzymes' cyanide-insensitive acyl-CoA oxidase and catalase. The peroxisomal yield was less increased in Zucker than in Sprague-Dawley rats, while the enzyme activities were similarly i…
The Effect of Indobufen on the Activities of Selected Rat Liver Phase I and Phase II Drug Metabolizing Enzymes, Peroxisomal β-oxidation and Hepatic G…
1994
Abstract Oral administration of indobufen to male rats for three days at daily doses of 5, 10 and 20 mg kg−1 resulted in no changes in liver total glutathione, cytosolic glutathione S-transferases or microsomal epoxide hydrolase. Reduced glutathione appeared slightly diminished to about 84% of control at the highest dose level. Microsomal cytochrome P450-dependent ethoxyresorufin O-de-ethylase and pentoxyresorufin de-alkylase activities were decreased to 64% (not significantly) and 67% of control at the lowest dose level. 6α- and 7α-Hydroxytestosterone activities were decreased to 67 and 68% of control at the highest dose level. Cyanide-insensitive peroxisomal fatty acid β-oxidation was inc…
Oxidative and lysosomal capacity in skeletal muscle of mice after endurance training of different intensities
1978
The activity of certain enzymes of energy metabolism (cytochrome c oxidase, citrate synthase, malate dehydrogenase, and lactate dehydrogenase) and of lysosomes (beta-glucuronidase, beta-N-acetylglucosamindase, arylsuphatase, ribonuclease, deoxyribonuclease, acid phosphatase, and cathepsin D) was assayed from m. rectus femoris of mice trained 5 days per week, 1 hr per day for 4 weeks according to 4 different programmes: I. running speed 20 m/min, horizontal track, II. 25 m/min, horizontal track, III. 20 m/min 8 degrees uphill inclination, and IV. 25 m/min 8 degrees uphill inclination. Oxidative capacity increased and anaerobic capacity decreased without distinction between the different tran…
?-Glucuronidase activity in trained red and white skeletal muscle of mice
1978
We studied the effects of prolonged running exercise (5 days a week, 1.5 h per day at a speed of 17.6 m/min) on the activity of some acid hydrolases (beta-glucuronidase, beta-N-acetylglucosaminidase, acid phosphatase and cathepsin D) and three enzymes of energy metabolism (cytochrome c oxidase, lactate dehydrogenase and creatine kinase) in the distal and in the proximal, the predominantly white and red parts, respectively, of the vastus lateralis-muscle from mice. The acid hydrolase activity levels were 1.24--1.69 higher in untrained red muscle compared to untrained white muscle. The light training applied increased the activity of beta-glucuronidase in both red and white muscle. No other s…
Long-term expression of differentiated functions in hepatocytes cultured in three-dimensional collagen matrix.
1998
Hepatocytes entrapped in collagen gel and cultured in serum-free conditions survived longer than cells cultured on plastic (5 days vs. 3 weeks), showed fewer signs of early cell senescence (no increase in c-fos oncoprotein expression), and maintained the expression of differentiated hepatic metabolic functions over a longer period of time. Cells cultured in collagen gels retained their ability to respond to hormones. The insulin-stimulated glycogen synthesis rate remained fairly constant during 18 days in culture (between 5.4 +/- 0.37 and 9 +/- 2.7 nmol glucose/h/microg DNA). Collagen-cultured hepatocytes recovered glycogen stores to levels similar to those found in liver, or in hepatocytes…
The effects of enzalutamide and abiraterone on skeletal related events and bone radiological progression free survival in castration resistant prosta…
2017
Two new drugs, the CYP17 inhibitor abiraterone acetate and the androgen receptor (AR) antagonist enzalutamide, have recently shown to prolong OS prior chemotherapy or in docetaxel treated mCRPC patients, using steroidal therapy or placebo as control group. Updated analyses underlined the role of these new agents on two prostate-specific endpoints as radiographic progression-free survival (rPFS) and time to first skeletal-related event (tSRE). On the basis of these reports, we made an indirect comparison between abiraterone and enzalutamide. We obtained a clinically but not significant difference favouring enzalutamide over abiraterone in terms of rPFS (HR 0.48, 95% CI 0.22â1.02). No signi…
Mitochondrial myopathy with lactic acidosis and deficient activity of muscle succinate cytochrome-c-oxidoreductase
1984
A male infant had severe muscular hypotonia from birth. Recurrent vomiting with dehydration and severe metabolic acidosis complicated the course. Elevated lactate (up to 12.3 mmol/l; n less than 2), pyruvate (0.4 mmol/l; n less than 0.05) and alanine levels were found in serum with an abnormal lactate/pyruvate ratio (greater than 30; n less than 15). In urine the concentrations of lactate, pyruvate, alanine and of several intermediates of the citric acid cycle were increased. In muscle, numerous disseminated "ragged red fibres" were found by light microscopy; muscle fibres were found to contain subsarcolemmal aggregates of mitochondria, lipid droplets and glycogen by electromicroscopical me…
Role of thyroid state on induction by ciprofibrate of laurate hydroxylase and peroxisomal enzymes in rat liver microsomes.
1993
The effects of hypothyroidism and hyperthyroidism upon liver microsomal omega-laurate hydroxylase activity (cytochrome P450 IV A1-dependent), peroxisome proliferation marker enzyme activities and acyl CoA oxidase (AOX) expression induced by ciprofibrate (2 mg/kg/day during 8 days) were studied in the male Wistar rat so as to clarify firstly the possible involvement of thyroid hormones in the modification of peroxisomal ciprofibrate-induced enzyme activities in relation to hepatic microsomal cytochrome P450 IV A1 induction, and secondly the possible direct effect of thyroid hormones on the gene expression of specific peroxisomal enzymes. No significant change was found in the ciprofibrate-in…
Permissive and suppressive effects of dexamethasone on enzyme induction in hepatocyte co-cultures.
2002
1. Steroids are known to act as permissive factors in hepatocytes. This study shows that dexamethasone (DEX) is a permissive factor for induction of CYP2B1/2, CYP3A1, CYP2A1 and probably also CYP2C11 in cultures with primary rat hepatocytes. 2. The induction factor of phenobarbital (PB)-induced formation of 16beta-hydroxytestosterone (OHT), a testosterone biotransformation product predominantly formed by CYP2B1, is increased 18-fold by the addition of 32 nM DEX to the culture medium. Interestingly, higher concentrations of DEX up to 1000 nM led to a concentration-dependent maximally 5-fold decrease (p = 0.002) of phenobarbital-induced 16beta-OHT formation compared with the effect observed w…