several transporters appear to be important in transporting various drugs. many patients, who receive morphine as analgesic medication, also receive other medications with potency of changing morphine transport by affecting p-glycoprotein (p-gp) and oatp2 transport system. this could influence morphine pharmacokinetics and pharmacodynamics. the aim of present study was to elucidate the transpor...

Several transporters appear to be important in transporting various drugs. Many patients, who receive morphine as analgesic medication, also receive other medications with potency of changing morphine transport by affecting P-glycoprotein (P-GP) and oatp2 transport system. This could influence morphine pharmacokinetics and pharmacodynamics. The aim of present study was to elucidate the transpor...

Morphine and other mu opioids mimic and/or modulate the discriminative stimulus (DS) effects of cocaine, possibly reflecting mutual stimulation of mesolimbic dopamine activity. Less is known about the capacity of cocaine and related stimulants to modulate the DS effects of morphine. The present study investigated the effects of cocaine, amphetamine, and reference drugs, administered alone and w...

Regulating main brain-uptake transporter of morphine may restrict its tolerance generation, then modify its antinociception. In this study, more than 2 fold higher intracellular uptake concentrations for morphine and morphine-6-glucuronide (M6G) were observed in stable expression cells, HEK293-hOATP2B1 than HEK293-MOCK. Specifically, the Km value of morphine to OATP2B1 (57.58 ± 8.90 μM) is 1.4-...

The effect of 5 drugs on the transport of several substrates, including the chemotherapeutic agent nitrogen mustard; choline; two nonmetabolizable amino acids, a-aminoisobutyric acid and cycloleucine; the glucose analog, 3-0-methyl-Dglucose; and the heme precursor, 6-aminolevulinic acid; was undertaken in L5178Y murine lymphoblasts in vitro. Trans port of both hydrolyzed nitrogen mustard and ch...

The effect of 5 drugs on the transport of several substrates, including the chemotherapeutic agent nitrogen mustard; choline; two nonmetabolizable amino acids, a-aminoisobutyric acid and cycloleucine; the glucose analog, 3-0-methyl-Dglucose; and the heme precursor, 6-aminolevulinic acid; was undertaken in L5178Y murine lymphoblasts in vitro. Trans port of both hydrolyzed nitrogen mustard and ch...

The present study was conducted to investigate the effects of repeated treatment with morphine on the drug's antinociceptive effects, intestinal absorption, and transepithelial transport. The antinociceptive effects of morphine in rats were markedly decreased after repeated oral administration of the drug for 5 d, indicating the development of tolerance. In the morphine-tolerant rats, intestina...

BACKGROUND The efflux transporter P-glycoprotein, a member of the adenosine triphosphate-binding cassette superfamily, is a major determinant of the pharmacokinetics and pharmacodynamics of the opioid loperamide, a well-recognized antidiarrheal agent. Animal studies indicate that P-glycoprotein limits morphine entry into the brain. In this study, the authors examined whether other opioids of im...