normorphine and Morphine-Dependence

The isolated guinea pig ileum provides a model in which drug dependence can be induced in normal neurons. The characteristics of opiate dependence in the ileum closely resemble those of dependence in whole animals. Convergent dependence on normorphine, clonidine, and adenosine can be separately induced in the ileum in vitro. Use of selective antagonists indicates that both acetylcholine and substance P participate in the withdrawal response associated with all three of these dependencies. The demonstration that adenosine derivatives suppress opiate withdrawal in the guinea pig ileum and in mice raises the possibility that they might act similarly in man. The point at which the dependencies on normorphine, clonidine, and adenosine converge is probably below their separate recognition sites and is possibly at the level of adenylate cyclase regulation.

Topics: Acetylcholine; Adenosine; Animals; Clonidine; Cyclic AMP; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Morphine; Morphine Dependence; Morphine Derivatives; Muscle Contraction; Muscle, Smooth; Myenteric Plexus; Naloxone; Pertussis Vaccine; Scopolamine; Substance P; Substance Withdrawal Syndrome; Substance-Related Disorders; Theophylline; Yohimbine

A cation-selective exhaustive injection and sweeping micellar EKC (CSEI-Sweep-MEKC) was established to analyze morphine and its four metabolites, including codeine, normorphine (NM), morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G). After SPE, the urine samples were analyzed by this CE method. The phosphate buffer (75 mM, pH 2.5) containing 30% methanol was first filled into an uncoated fused-silica capillary (40 cm, 50 microm id), then a high-conductivity buffer (120 mM phosphate, 10.3 kPa for 99.9 s) followed. The pretreated urine sample was loaded by electrokinetic injection (10 kV, 600 s). The stacking and separation were performed by using phosphate buffer (25 mM, pH 2.5) containing 22% methanol and 100 mM SDS at -20 kV, and detected at 200 nm. During method validation, calibration plots were linear (r > or = 0.998) over a range of 30-3000 ng/mL for morphine, NM, and codeine, 100-2000 ng/mL for M6G, and 80-3200 ng/mL for M3G. The LODs (S/N = 5, sampling 600 s at 10 kV) were 10 ng/mL for morphine, NM, and codeine, 35 ng/mL for M6G, and 25 ng/mL for M3G. This stacking CE method could increase 2500-fold sensitivity of codeine, when comparing with CZE. Five addicts' urine specimens were analyzed. Their results were compared with those of LC-MS-MS, and showed good coincidence. This method could be feasible for monitoring morphine and its metabolites in forensic interest and pharmacokinetic investigations.

Topics: Chromatography, Liquid; Chromatography, Micellar Electrokinetic Capillary; Codeine; Humans; Morphine; Morphine Dependence; Morphine Derivatives; Reproducibility of Results; Solid Phase Extraction; Tandem Mass Spectrometry

The effects of glucose in vitro at concentrations of 100, 200 and 400 mg/dl on responses of the guinea-pig ileum and mouse vas deferens to opiates were studied. Responses of the electrically stimulated ileum to normorphine were significantly reduced (IC50 values: 26.3 +/- 4.3, 40.5 +/- 3.7 and 71.8 +/- 16.6 nM) as the glucose concentration increased, whereas the potency of normorphine was not affected by equimolar substitutions of glucose with the nonmetabolizable sugar 3-O-methylglucose. The potency of naloxone to induce withdrawal contractions of ilea incubated in Ringer's solution for 3 or 4.5 hr with 1 microM morphine was also significantly decreased as the concentration of glucose in the incubations increased, indicating a reduction of acute dependence development by high glucose. The potency of normorphine was also reduced by increasing concentrations of glucose in electrically stimulated vasa deferentia from nondiabetic (db/m+, m+/m+) C57BL/KsJ mice (IC50 values: 0.53 +/- 0.01, 0.77 +/- 0.01 and 1.84 +/- 0.03 nM), but not in vasa deferentia from their diabetic (db/db) littermates. These results support our hypothesis that the decreased sensitivity to morphine and decreased development of physical dependence on morphine in in vivo models of diabetes reported previously by our laboratory is due primarily to the hyperglycemia associated with diabetes.

Topics: Animals; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Electric Stimulation; Glucose; Guinea Pigs; Ileum; In Vitro Techniques; Male; Mice; Mice, Inbred C57BL; Morphine; Morphine Dependence; Morphine Derivatives; Muscle Contraction; Naloxone; Vas Deferens

The stable derivatives of adenosine, 2-chloroadenosine and N6-cyclohexyladenosine, with high affinity for the A1 (Ri) adenosine receptor, suppress the naloxone-precipitated withdrawal contracture of the opiate-dependent guinea-pig ileum in vitro. These adenosine derivatives also inhibit naloxone-precipitated jumping, diarrhea and weight-loss in morphine-dependent mice. This effect was not due to sedation, since (i) 2-chloroadenosine was effective at a non-sedative dose and (ii) sedative doses of chlordiazepoxide were ineffective.

Topics: 2-Chloroadenosine; Adenosine; Animals; Behavior, Animal; Chlordiazepoxide; Guinea Pigs; Humans; Ileum; Male; Mice; Mice, Inbred Strains; Morphine Dependence; Morphine Derivatives; Muscle Contraction; Myenteric Plexus; Naloxone; Receptors, Cell Surface; Receptors, Purinergic; Substance Withdrawal Syndrome

Topics: Animals; Female; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Male; Morphine Dependence; Morphine Derivatives; Muscle Contraction; Muscle, Smooth; Naloxone; Naltrexone; Narcotic Antagonists

Topics: Acetylcholine; Animals; Calcium; Cations, Divalent; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Lanthanum; Male; Morphine Dependence; Morphine Derivatives; Muscle Contraction; Muscle, Smooth; Myenteric Plexus; Naloxone

Topics: Acetylcholine; Animals; Clonidine; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Male; Morphine Dependence; Morphine Derivatives; Muscle Contraction; Naloxone; Neuromuscular Junction