Search results for "CYP"
showing 10 items of 480 documents
Carcinogenic Etheno DNA Adducts in Alcoholic Liver Disease: Correlation with Cytochrome P-4502E1 and Fibrosis.
2017
BACKGROUND One mechanism by which alcoholic liver disease (ALD) progresses is oxidative stress and the generation of reactive oxygen species, among others due to the induction of cytochrome P-4502E1 (CYP2E1). Experimental data underline the key role of CYP2E1 because ALD could be partially prevented in rats by the administration of the specific CYP2E1 inhibitor chlormethiazole. As CYP2E1 is linked to the formation of carcinogenic etheno DNA adducts in ALD patients, a causal role of alcohol-induced CYP2E1 in hepatocarcinogenesis is implicated. The purpose of this study was to investigate CYP2E1 induction in ALD, and its correlation with oxidative DNA lesions and with hepatic histology. METHO…
Studies on the Effects of the Antiandrogen Cyproterone Acetate on Social Encounters Between Pairs of Male Mice
1988
An attempt was made in two experiments to reinvestigate the effects of the antiandrogen cyproterone acetate (CA) on mouse social behavior in a variety of ethologically-assessed paired encounters. The data confirm that CA reduces offense (threat and attack) in animals when both subjects receive the material but that CA has no such action in other pairings. This suggests that CA's major suppressive effect on "hostility" is expressed in mice via a reduction in "attack-promoting" pheromone production. Indeed, there was evidence in the more chronic study that CA, could augment (via a central mechanism?) offense in subjects paired with docile anosmic opponents. Changes in defense were largely res…
Difference between Guinea Pig and Rat in the Liver Peroxisomal Response to Equivalent Plasmatic Level of Ciprofibrate
1996
Abstract Guinea pig was previously classified as a species nonresponsive to peroxisome proliferators. However, none of the previous reports was based on pharmacokinetic data. Here, after a comparative pharmacokinetic study between guinea pig and rat, we evaluate the guinea pig liver peroxisomal response to ciprofibrate, a hypolipemic agent and a potent peroxisome proliferator in rat. (1) Pharmacokinetic results show that plasmatic concentrations of ciprofibrate are equivalent in guinea pig and rat when guinea pigs are treated with ciprofibrate at 30 mg/kg twice a day and rats are treated at 3 mg/kg once a day. (2) The treatment of guinea pigs at 30 mg/kg twice a day for 2 weeks leads to a s…
Epizootic cutaneous papillomatosis, cortisol and male ornamentation during and after breeding in the roach Rutilus rutilus.
2004
The prevalence of epidermal papillomatosis in roach is known to peak during the spawning period and to be higher in males than in females. The high occurrence of papillomatosis in polluted waters suggests that stress may contribute to the outbreak of the disease. However, little is known about breeding-induced stress in fish and its relationship with diseases. In this study, plasma cortisol concentration, hematocrit and the relative size of the spleen were determined in healthy and diseased male and female roach Rutilus rutilus during and shortly after spawning in a wild population. In addition, the sexual ornamentation (breeding tubercles on the lateral sides and on the frontal) of male ro…
Formation and metabolism of catecholestrogens in depressed patients.
1990
Abstract The evidence that catecholestrogens are formed in the brain and exert behavioral effects in animal models suggests that these steroids might have psychotropic activities. In the present investigation, the formation and metabolism of catecholestrogens were studied in depressed patients. Twenty-four-hr urine samples were collected from 6 male patients (59 ± 8 years) with endogenous retarded depression (subtype primary, endogenous, and recurrent according to Research Diagnostic Criteria) and from 12 male control subjects (51 ± 4 years). The patients were treated with the monoamine oxidase inhibitor tranylcypromine (10–40 mg/day for 3–4 weeks). The concentrations of primary estrogens, …
Ethopharmacological studies on the effects of antihormones on rodent agonistic behavior with especial emphasis on progesterone.
1991
The effects of a range of antiandrogens and antiestrogens on conflict behaviors in laboratory rats and mice are reassessed in the light of recent studies applying ethophamacological analyses (recording the full spectrum of behaviors) to such investigations. It is argued that any antihostility properties of the antiandrogen cyproterone acetate are largely a consequence of indirect actions on odor communication, whereas antiestrogens (e.g., tamoxifen and CI 680) seem to have more fundamental motivational effects in addition to communicatory actions. A detailed example of the approach is provided in which progesterone (which can be antiandrogenic) is given to rats paired in different ways. The…
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…
Treatment of advanced prostatic cancer with parenteral cyproterone acetate: a phase III randomised trial.
1980
Summary— Forty-two patients with previously untreated T3/4 N1-4 MO/1 prostatic adenocarcinoma were treated with either cyproterone acetate (n=21; 300 mg intramuscularly per week) or oestradiol undecylate (n=21; 100 mg intramuscularly per month) after extensive staging which included open skeletal biopsy and pelvic lymphadenectomy in some cases. Subjective and objective parameters as well as signs of drug toxicity were recorded regularly. Evaluation after 6 months showed cyproterone acetate to be more effective in the following respects: (1) the significantly different castration effect as judged by plasma testosterone, (2) the objective voiding pattern and tumour response, with regression o…
Testosterone metabolism in benign prostatic hypertrophy: in vivo studies of gestonorone caproate and cyproterone acetate.
1976
Summary 18 patients with obstructive benign prostatic hypertrophy were studied. A 5-day treatment with gestonorone caproate (200 mg daily and 200 mg on alternate days) and cyproterone acetate (300 mg daily) suppressed the plasma LH and serum LH levels. Subsequently, H3-testosterone was injected intravenously and its elimination from plasma and uptake and metabolism in the BPH tissue studied. The elimination of total radioactivity and H3-testosterone from plasma was not altered after the 3 treatment regimens as compared to the control group. The uptake of total radioactivity into BPH tissue and its intraprostatic metabolism particularly to dihydrotestosterone was significantly suppressed in …