Search results for "Membrane Transport"
showing 10 items of 215 documents
Effects of risperidone on the acquisition and reinstatement of the conditioned place preference induced by MDMA
2013
Some users of 3,4-methylenedioxymethylamphetamine (MDMA or ecstasy) abuse this drug and/or become concerned about their use. These individuals would benefit greatly from the development of pharmacological strategies to reduce MDMA consumption. We have previously observed that antipsychotics block acquisition and expression of the conditioned place preference (CPP) induced by MDMA, though they do not modify priming-induced reinstatement of MDMA-induced CPP after extinction. In the present study we have evaluated the capacity of the mixed serotonin (5-HT2A)/dopamine (DA D2) antagonist risperidone to block acquisition and reinstatement of MDMA induced-CPP. Adolescent male mice conditioned with…
Controlled reperfusion after hypothermic heart preservation inhibits mitochondrial permeability transition-pore opening and enhances functional recov…
2006
We investigated whether low-pressure reperfusion may attenuate postischemic contractile dysfunction, limits necrosis and apoptosis after a prolonged hypothermic ischemia, and inhibits mitochondrial permeability transition-pore (MPTP) opening. Isolated rats hearts ( n = 72) were exposed to 8 h of cold ischemia and assigned to the following groups: 1) reperfusion with low pressure (LP = 70 cmH2O) and 2) reperfusion with normal pressure (NP = 100 cmH2O). Cardiac function was assessed during reperfusion using the Langendorff model. Mitochondria were isolated, and the Ca2+resistance capacity (CRC) of the MPTP was determined. Malondialdehyde (MDA) production, caspase-3 activity, and cytochrome c …
Inhibition of different GABA transporter systems is required to attenuate epileptiform activity in the CA3 region of the immature rat hippocampus
2014
GABA transporters (GATs) are an essential element of the GABAergic system, which regulate excitability in the central nervous system and are thus used as targets for anticonvulsive therapy. However, in the immature nervous system the functions of the GABAergic system and the expression profile of GATs are distinct from the adult situation, obscuring to predict how different GAT isoforms influence epileptiform activity. Therefore we analyzed the effects of subtype specific GAT inhibitors on repetitive epileptiform discharges using field potential and whole-cell patch-clamp recordings in the CA3 region of hippocampal slices of immature (postnatal days 4-7) rats. These experiments revealed tha…
Diagnostic value of CD34 immunostaining in desmoplastic trichilemmoma.
1998
Desmoplastic trichilemmoma (DT) is a variant of trichilemmoma, characterized by a central prominent desmoplastic component which may simulate invasive carcinoma. We have studied the morphologic and immunohistochemical features of seven cases of DT. Immunohistochemistry was performed on paraffin sections using monoclonal antibodies to CD34 (QBEND/10), vimentin and GCDFP-15. CD34 was also tested in seven cases of basal cell carcinoma (BCC), three with outer root sheath differentiation and four with morphea-form features, and five squamous cell carcinomas. Histologically, features of conventional trichilemmoma were seen at the periphery of the seven lesions. In contrast, at the center, the epi…
Regulation of organic anion transporters in a new rat model of acute and chronic cholangitis resembling human primary sclerosing cholangitis
2002
Primary sclerosing cholangitis (PSC) is a cholestatic liver disease of unknown etiology. Although the primary defect affects cholangiocytes, cholestatic injury of hepatocytes may promote further liver damage. Since down-regulation of hepatocellular organic anion transporters is implicated in the molecular pathogenesis of cholestasis, expression of these transporters was determined in a novel rat model, which closely resembles human PSC.Hepatic protein and mRNA expression of basolateral (Ntcp, Oatp1, 2 and 4) and canalicular (Mrp2, Bsep) organic anion transporters were analyzed 1, 4 and 12 weeks after induction of experimental PSC by 2,4,6-trinitrobenzenesulfonic acid (TNBS).Specific down-re…
Induction of the fatty acid transport protein 1 and acyl-CoA synthase genes by dimer-selective rexinoids suggests that the peroxisome proliferator-ac…
2000
The intracellular fatty acid content of insulin-sensitive target tissues determines in part their insulin sensitivity. Uptake of fatty acids into cells is a controlled process determined in part by a regulated import/export system that is controlled at least by two key groups of proteins, i.e. the fatty acid transport protein (FATP) and acyl-CoA synthetase (ACS), which facilitate, respectively, the transport of fatty acids across the cell membrane and catalyze their esterification to prevent their efflux. Previously it was shown that the expression of the FATP-1 and ACS genes was controlled by insulin and by peroxisome proliferator-activated receptor (PPAR) agonists in liver or in adipose t…
Mutations in the PDS Gene in German Families with Pendred’s Syndrome: V138F Is a Founder Mutation
2003
Pendred's syndrome, an autosomal-recessive condition characterized by congenital sensorineural hearing loss and goiter, is caused by mutations in the PDS gene. Located on chromosome 7q22-q31, it encodes a chloride-iodide transporter expressed in the thyroid, inner ear, and kidney. We investigated the PDS gene of six affected individuals from four unrelated families with Pendred's syndrome by direct sequencing. PDS mutations were identified in homozygous or compound heterozygous state in all six cases. A homozygous missense mutation leading to the amino acid substitution S133T was detected in a family of Turkish origin. The mutations found in the other affected individuals, who originate fro…
Dopamine-related genes and spontaneous smoking cessation in ever-heavy smokers
2011
Several studies have provided evidence for associations of polymorphisms located in and near dopamine-related genes and nicotine dependence and other smoking-related phenotypes, including pharmacogenetic interactions. Aim: The purpose of the present work was to examine the association of SNPs in the DOPA decarboxylase (DDC), dopamine receptor D2 (DRD2) and dopamine transporter (SLC6A3) genes with smoking cessation in a large retrospective study featuring approximately 900 cessation events. Materials & methods: Data originated from the enrollment questionnaire of the epidemiological ESTHER study of community-dwelling adults aged 50–74 years, conducted in the German state of Saarland bet…
Carnitine transport into muscular cells. inhibition of transport and cell growth by mildronate
2000
Carnitine is involved in the transfer of fatty acids across mitochondrial membranes. Carnitine is found in dairy and meat products, but is also biosynthesized from lysine and methionine via a process that, in rat, takes place essentially in the liver. After intestinal absorption or hepatic biosynthesis, carnitine is transferred to organs whose metabolism is dependent on fatty acid oxidation, such as heart and skeletal muscle. In skeletal muscle, carnitine concentration was found to be 50 times higher than in the plasma, implicating an active transport system for carnitine. In this study, we characterized this transport in isolated rat myotubes, established mouse C2C12 myoblastic cells, and …
Expression of Na+-d-glucose cotransporter SGLT2 in rodents is kidney-specific and exhibits sex and species differences
2012
With a novel antibody against the rat Na+-d-glucose cotransporter SGLT2 (rSGLT2-Ab), which does not cross-react with rSGLT1 or rSGLT3, the ∼75-kDa rSGLT2 protein was localized to the brush-border membrane (BBM) of the renal proximal tubule S1 and S2 segments (S1 > S2) with female-dominant expression in adult rats, whereas rSglt2 mRNA expression was similar in both sexes. Castration of adult males increased the abundance of rSGLT2 protein; this increase was further enhanced by estradiol and prevented by testosterone treatment. In the renal BBM vesicles, the rSGLT1-independent uptake of [14C]-α-methyl-d-glucopyranoside was similar in females and males, suggesting functional contribution of…