Prostaglandin E2 (PGE2) is the most abundant prostanoid in the kidney, affecting a wide range of renal functions. Conflicting data have been reported regarding the effects of PGE2 on tubular water and ion transport. The amiloride-sensitive epithelial sodium channel (ENaC) is rate limiting for transepithelial sodium transport in the aldosterone-sensitive distal nephron.
View Article and Find Full Text PDFProstaglandins such as prostaglandin E2 (PGE2) play a pivotal role in physiological and pathophysiological pathways in gastric mucosa. Little is known about the interrelation of the prostaglandin E (EP) receptors with the prostaglandin transporter OATP2A1 in the gastric mucosa and gastric carcinoma. Therefore, we first investigated the expression of OATP2A1 and EP4 in normal and carcinoma gastric mucosa.
View Article and Find Full Text PDFNaunyn Schmiedebergs Arch Pharmacol
September 2014
Flavonoids such as quercetin and kaempferol mediate several health protective effects, e.g., anticancer effects.
View Article and Find Full Text PDFThe antiviral lamivudine is cleared predominantly by the kidney with a relevant contribution of renal tubular secretion. It is not clear which drug transporters mediate lamivudine renal secretion. Our aim was to investigate lamivudine as substrate of the renal drug transporters organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins MATE1 and MATE2-K.
View Article and Find Full Text PDFMembers of the human SLC superfamily such as organic anion transporting polypeptide 1B1 (OATP1B1), OATP1B3, and organic cation transporter 1 (OCT1) are drug uptake transporters that are localised on the basolateral membrane of hepatocytes mediating the uptake of drugs such as atorvastatin and metformin into hepatocytes. Ingredients of food such as flavonoids influence the effects of drugs, e.g.
View Article and Find Full Text PDFThe human organic anion transporting polypeptide 1B3 (OATP1B3), located in the basolateral membrane of hepatocytes, mediates the uptake of endogenous substrates such as taurocholate and drugs from blood into hepatocytes. The transport activity of OATP1B3 is influenced by positively charged amino acids, which are facing the central pore. Molecular modeling was performed to select conserved positively charged amino acids, which may influence transport activity and anchoring of OATP1B3 in the plasma membrane.
View Article and Find Full Text PDFThe therapeutic effects and metabolism of mesalazine (5-aminosalicylic acid) in patients with inflammatory bowel disease require intracellular accumulation of the drug in intestinal epithelial cells and hepatocytes. The molecular mechanisms of mesalazine uptake into cells have not been characterized so far. Using human embryonic kidney cells stably expressing uptake transporters of the organic anion-transporting polypeptide (OATP) family, which are expressed in human intestine and/or liver, we found that mesalazine uptake is mediated by OATP1B1, OATP1B3, and OATP2B1 but not by OATP1A2 and OATP4A1.
View Article and Find Full Text PDFOATP1A2 and OATP2B1 are uptake transporters of the human organic anion transporting polypeptide (OATP) family with a broad substrate spectrum including several endogenous compounds as well as drugs such as the antihistaminic drug fexofenadine and HMG-CoA reductase inhibitors. Both transporters are localized in the apical membrane of human enterocytes. Flavonoids, abundantly occurring in plants, have previously been shown to interact with drug metabolizing enzymes and transporters.
View Article and Find Full Text PDFPurpose: Latanoprost, a prostaglandin F(2alpha) analogue, has become one of the most widely used medications for the treatment of glaucoma. The authors hypothesized that organic anion transporting polypeptides (OATPs) are responsible for the uptake of latanoprost into ocular tissues and, hence, that they contribute to the interindividual differences in drug concentrations and effects.
Methods: Expression of prostaglandin (PG) transporters (OATP2A1, OATP2B1) in human ocular tissues was determined using real-time RT-PCR and immunofluorescence.
The human organic anion-transporting polypeptide 2A1 (OATP2A1) is a prostaglandin transporter expressed in several tissues and plays an important role for local distribution of prostaglandins, which contribute to the integrity of gastric mucosa. Blockade of prostaglandin pathways by cyclooxygenase (COX) inhibitors has been associated with serious side effects such as gastrointestinal ulceration and bleeding. However, little is known regarding OATP2A1 expression in the upper gastrointestinal tract and the potential impact of cyclooxygenase inhibitors on OATP2A1 function.
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