Search results for "Barbital"
showing 10 items of 82 documents
Gastric mucosal resistance to acute injury in experimental portal hypertension
2001
The gastric mucosa of portal hypertensive rats exhibits important microvascular changes and a nitric oxide (NO)-dependent hyperemia. This study analyses whether portal hypertensive mucosa exhibits changes in its ability to withstand aggression. Portal hypertension was induced by partial portal vein ligation (PPVL) or common bile duct ligation (CBDL) and gastric damage was induced by oral administration of ethanol or aspirin. Experiments were performed in conscious or anaesthetized rats and some animals were pre-treated with the NO-synthesis inhibitor L-NAME. Conscious PPVL or CBDL rats showed an increased resistance to the damaging effects of ethanol. Oral administration of aspirin produced…
A Fresh Insight into the Interaction of Natural Products with Pregnane X Receptor
2008
The discovery that various drugs (e.g., phenobarbital) stimulate their own metabolism through a mechanism coined as enzymatic induction opened up a fascinating road that eventually led to the accurate biochemical characterization of the pregnane X receptor. After numerous studies, researchers have concluded that this receptor is activated by different endogenous steroids and a number of foreign lipophile ligands. Once activated, it induces the synthesis of oxygenases and conjugating enzymes. The activating ligands identified to date include many synthetic drugs, along with a number of natural products. The present review summarizes the data relating to the origin, chemistry, and pharmacolog…
A phenobarbital overdose: a case report
2017
Background: Phenobarbital is a long-acting barbiturate, responsible for many cases of poisoning, from unintentional overdose or attempted suicide. We report a case of phenobarbital overdose in a patient with history of depression. Patients and Methods: A 60 year old woman was admitted to our Internal Medicine Unit for drowsiness, irritability, difficulties in the maintenance of an upright position, dysphasia and weakness. She was suffering from depression and epilepsy and treated with phenobarbital 150 mg/die. Results: At the admittance, she had high fever and neck stiffness; phenobarbital serum levels were 71.2 mcg/ml (3 times u.n.l.); aminotransferases were 12-17u.n.l. Arterial blood pres…
Disposition and Anticoagulant Activity of the Enantiomers of Phenprocoumon in Phenobarbital Pretreated Rats
1978
The purpose of this study was to assess in rats the effect of enzyme induction on the stereoselective disposition and anticoagulant activity of phenprocoumon.
Influence of carbenoxolone on the anticonvulsant efficacy of conventional antiepileptic drugs against audiogenic seizures in DBA/2 mice
2004
Carbenoxolone, the succinyl ester of glycyrrhetinic acid, is an inhibitor of 11beta-hydroxy steroid dehydrogenase and gap junctional intercellular communication. It is currently used in clinical treatment of ulcer diseases. Systemic administration of carbenoxolone (1-40 mg/kg, intraperitoneally (i.p.)) was able to produce a dose-dependent decrease in DBA/2 audiogenic seizure severity score. Glycyrrhizin, an analogue of carbenoxolone inactive at the gap-junction level, was unable to affect audiogenic seizures at doses up to 30 mg/kg. In combination with conventional antiepileptic drugs, carbenoxolone, 0.5 mg/kg, i.p., which per se did not significantly affect the occurrence of audiogenic sei…
Effect of Injectable or Inhalational Anesthetics and of Neuroleptic, Neuroleptanalgesic, and Sedative Agents on Tumor Blood Flow
1988
Among other parameters, varying blood flow values may be responsible for tumor-to-tumor variabilities in the radiobiologically hypoxic cell fraction of experimental rodent tumors. To test whether changes in tumor blood flow may be caused by anesthetic agents often used in radiobiology, the effect of injectable and inhalational anesthetics and of neuroleptic, neuroleptanalgesic, and sedative agents on blood flow in subcutaneous DS-carcinosarcomas implanted in Sprague-Dawley rats has been investigated using the 85Kr clearance technique. In conscious rats, 20-100 min after animal instrumentation mean blood flow is 0.62 +/- 0.17 ml/g/min (mean +/- SD) in 0.75 +/- 0.15 g tumors at a mean arteria…
Species-specific mechanisms for cholesterol 7alpha-hydroxylase (CYP7A1) regulation by drugs and bile acids.
2005
The gene encoding cholesterol 7alpha-hydroxylase (CYP7A1) is tightly regulated in order to control intrahepatic cholesterol and bile acid levels. Ligands of the xenobiotic-sensing pregnane X receptor inhibit CYP7A1 expression. To retrace the evolution of the molecular mechanisms underlying CYP7A1 inhibition, we used a chicken hepatoma cell system that retains the ability to be induced by phenobarbital and other drugs. Whereas bile acids regulate CYP7A1 via small heterodimer partner and liver receptor homolog-1, mRNA expression of these nuclear receptors is unchanged by xenobiotics. Instead, drugs repress chicken hepatic nuclear factor 4alpha (HNF4alpha) transcript levels concomitant with a …
Dual role of epoxide hydratase in both activation and inactivation of benzo(a)pyrene.
1977
The effect of epoxide hydratase upon the mutagenicity of benzo(a)pyrene was investigated using two Salmonella typhimurium strains (TA 1537 and TA 98). These two bacterial strains were found to differ characteristically in their susceptibility to different mutagens biologically produced from benzo(a)pyrene providing a diagnostic tool to investigate which types of mutagenic metabolites were produced in various metabolic situations. The results showed that the pattern of mutagenic metabolites produced by microsomes from methylcholanthrene-treated mice was very different from that produced by microsomes from phenobarbital-treated or untreated mice. However in all cases at least two mutagenic me…
Modulation of cytochrome P450 1A in sea bass liver by model substances and seawater extracts
1998
Abstract 1. 1. Immunochemical and catalytic assays for cytochrome P450 1A induction in liver of sea bass Dicentrarchus labrax treated with different model substances and organic seawater extracts have been performed. 2. 2. Ethoxyresorufin-O-deethylase (EROD) activities in fish liver were elevated by Arochlor 1254 (Aro), 3-methylcholanthrene (MC) and β-naphtoflavone (βNF). but not by phenobarbital (PB) treatment. 3. 3. Elevated levels of P450 1A protein followed by induction of EROD activity were detected only in βNF treated fish. 4. 4. Treatment of fish with organic seawater extracts revealed that there is no simple correlation between EROD activities and its catalyst P450 1A level. Seawate…
Dupuytren's contracture as result of prolonged administration of phenobarbital
2011
Dupuytren's disease is a fibroproliferative condition involving the superficial palmar fascia, leading to a progressive and irreversible flexion of the fingers. In literature, there are different opinions regarding the phenobarbital, a common antiepileptic drug, and its effective role in the genesis and development of Dupuytren's disease. In this retrospective investigation the association between phenobarbital and Dupuytren's contracture is discussed.Three patients in treatment with phenobarbital who had no others significant risk factors for Dupuytren's contracture were included in this study. The disease occurred after one to four years of drug therapy, at dosage of 100 mg/day. After sur…