BACKGROUND Morphine has been widely used as a clinical anesthetic and analgesic. However, abuse of morphine might result in psychological and physiological dependence. Previous studies have indicated that memory mechanisms play critical roles in morphine dependence. METHODS Morphine dependence was established in mice utilizing place preference conditioning (CPP). We observed changes in the me...

The transport of opioid analgesics across the blood-brain barrier (BBB) is an important determinant of their therapeutic effects. The human brain is protected by the BBB, which consists of brain capillary endothelial cells linked with tight junctions. It is well established that the polarized expression of numerous transporters and receptors at the brain capillary endothelial cells controls the...

The ability of P-glycoprotein (P-gp) to transport naturally occurring and synthetic opiate analgesics was investigated. Multidrug-resistant Chinese hamster ovary cells (B30) were found to accumulate significantly lower amounts of morphine than their drug-sensitive counterparts (B1). This decreased accumulation was reversed upon depletion of cellular stores of ATP. In addition, morphine bound to...

The ventral tegmental area (VTA) and its dopaminergic projections appear to mediate some of the rewarding properties of opiates, cocaine, and other drugs of abuse. In a previous study, we demonstrated that chronic morphine and cocaine exert common actions on tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, in this dopaminergic brain reward region (Beitner-Johnson an...

AND BRENDA COLASANTI 23 Acetylcholinesterase Inhibition and Morphine Effects in Morphine Tolerant and Dependent Mice. HEMENDRA N. BHARGAVA AND E. LEONG WAY 31 Studies on the Transport of Morphine into the Cerebrospinal Fluid of Rabbits. J. H. WANG AND A. E. TAKEMORI 41 The Effect of 6-Hydroxydopamine on Morphine Tolerance and Physical Dependence. GLADYS FRIEDLER, HEMENDRA H. BHARGAVA, RAYMOND Q...

Transcellular active tubular transport of organic cations occurs in the proximal renal tubule in the direction of excretion. These organic cations may be primary, secondary, tertiary, or quaternary amines. Endogenous neurohumors such as choline and catecholamines and drugs such as morphine and tetraethylammonium are representative transportable organic cations. Competitive inhibition for transp...

AND BRENDA COLASANTI 23 Acetylcholinesterase Inhibition and Morphine Effects in Morphine Tolerant and Dependent Mice. HEMENDRA N. BHARGAVA AND E. LEONG WAY 31 Studies on the Transport of Morphine into the Cerebrospinal Fluid of Rabbits. J. H. WANG AND A. E. TAKEMORI 41 The Effect of 6-Hydroxydopamine on Morphine Tolerance and Physical Dependence. GLADYS FRIEDLER, HEMENDRA H. BHARGAVA, RAYMOND Q...

BACKGROUND AND THE PURPOSE OF THE STUDY Morphine-6-glucuronide (M6G) is a potent metabolite of morphine which has high penetration into the brain despite its high polarity, which could be the result of an active transport system involved in M6G transport through blood brain barrier. Examples of such transporters are p-glycoprotein (PGP), probenecid-sensitive transport mechanism, multidrug resis...

BACKGROUND Evidence obtained from porcine cell cultures and experiments in laboratory animals indicates that transmembrane transporters may play a role in the distribution of the active morphine metabolite morphine-6-glucuronide (M6G). This was evaluated in a study in healthy volunteers. METHODS Ten subjects received an intravenous M6G infusion for 30 min at a dosage of 0.5 mg/kg body weight,...

Morphine, an effective but addictive analgesic, can profoundly affect the inflammatory response to pathogens, and long-term use can result in morphine tolerance. Inflammasomes are protein complexes involved in the inflammatory response. The nucleotide-binding oligomerization domain-like receptor (NLR) Family Pyrin Domain Containing (NLRP) 12 (NLRP12) inflammasome has been reported to have anti-...