Morphine tolerance and dependence induced by intraventricular injection

Injection of small quantities of morphine into the cerebral ventricular system of awake, relatively unrestrained, monkeys depressed or abolished operant food-reinforced lever pressing. After repeated injections progressively higher doses of morphine were needed to depress responding. Also, dependence could be demonstrated in these animals by precipitating specific abstinence signs with an antagonist.     

Depression of norepinephrine and 5-hydroxytryptamine in the brain by benzoquinolizine derivatives

The effects of two benzoquinolizine derivatives on the 5-hydroxytryptamine and norepinephrine content of the brain of mice, and some pharmacological actions, are described. Certain central effects (such as sedation and narcosis potentiation) of benzoquinolizine derivatives and possibly of Rauwolfia alkaloids may be due to changes of norepinephrine metabolism rather than to changes of 5-hydroxytryptamine metabolism in the brain.     

Narcotic tolerance and dependence: lack of relationship with serotonin turnover in the brain

Serotonin turnover was measured in mouse brain by means of the conversion of radioactivity from labeled tryptophan into serotonin. Animals with a high degree of tolerance to and physical dependence on morphine did not differ from control mice.     

Effect of 5-hydroxytryptamine and iproniazid on pregnancy

The effects of 5-hydroxytryptamine and iproniazid on pregnancy in mice and rabbits were investigated. 5-Hydroxytryptamine can interrupt pregnancy at all stages in mice but is particularly effective early and late in pregnancy. Iproniazid exerts its action essentially in the first half of pregnancy. 5-Hydroxytryptamine produces striking hemorrhage in the placenta.     

Morphine and ethanol: selective depletion of regional brain calcium

Administration of morphine or ethanol to rats produces a decrease in regional brain calcium in vivo. This effect is selectively antagonized by the stereospecific narcotic antagonist naloxone. Reserpine and the dopamine-acetaldehyde conjugate salsolinol also produce a depletion of regional brain calcium, but only the salsolinol depletion is antagonized by naloxone. Experiments with naloxone provide evidence for two calcium-sensitive pools in the central nervous system.     

Teratogenic effect of 5-hydroxytryptamine in mice

The subcutaneous injection of a single dose of 5-hydroxytryptamine into pregnant mice produced a large number of fetal abnormalities, mostly of the eyes, limbs, and tail; the skull and central nervous system were also sometimes affected. These effects could result from the action of the drug on placental function and blood supply.     

Lysergic acid diethylamide: role in conversion of plasma tryptophan to brain serotonin (5-hydroxytryptamine)

Injections of D-lysergic acid diethylamide decrease the turnover rate of 5-hydroxytryptamine of rat brain, as measured from the conversion of (14)C-tryptophan into (14)C-5-hydroxytryptamine. The 2-bromolysergic acid diethylamide given in doses fivefold greater than those of lysergic acid diethylamide fails to change the rate of (14)C-tryptophan conversion into (14)C-5-hydroxytryptamine. The effect of D-lysergic acid diethylamide is discussed with regard to its action on brain serotonergic neurons and its psychotomimetic effects.     

Insect salivary glands: stimulation of fluid secretion by 5-hydroxytryptamine and adenosine-3',5'-monophosphate

Low concentrations (10(-9)M) of 5-hydroxytryptamine increase the rate of fluid secretion by isolated salivary glands of adult Calliphora. 5-Hydroxytry ptamine is present in Calliphora brain. Adenosine-3',5'-monophosphate (cyclic AMP) also stimulates fluid secretion and may be involved in the mode of action of 5-hydroxytryptamine.     

5-hydroxytryptamine in the carotid body of the cat

Glomus cells, at least in the carotid body of cats, contain catechol and indolamines. Cells containing adrenaline, noradrenaline, and 5-hydroxytryptamine were identified.     

5-hydroxytryptamine: a cytospecific growth stimulator of cultured fibroblasts

5-Hydroxytryptamine (serotonin) in micromolar amounts increased the growth of fibroblasts in culture while not affecting five other cell lines. Serotonin appeared to shorten the lag phase of cell growth. The effect was less when serotonin was added to the fibroblast culture after the initial 24-hour period. The two functional groups of the serotonin molecule were required for growth enhancement. Serotonin in millimolar concentrations was toxic to fibroblasts.     

Identification and assay of 5-hydroxytryptamine in molluscan tissues by fluorescence method

The fluorescence assay method has been used in the identification and quantitative estimation of 5-hydroxytryptamine (5-HT) in mollusks. Ganglia of a representative pelecypod contain more 5-HT than those of a gastropod. Most non-nerve tissues have low levels of 5-HT, which, except in "kidneys," may derive from nerve endings.     

Anatomically distinct opiate receptor fields mediate reward and physical dependence

Rats never before exposed to opioids rapidly learned to press a lever for microinjections of morphine into the ventral tegmental area. Challenge by a narcotic antagonist produced no signs of physical dependence. Dependence was not seen after long-term morphine infusions into the ventral tegmentum but was seen after similar infusions into the periventricular gray region. Thus a major rewarding property of morphine is independent of the drug's ability to produce physical dependence. These data challenge models of drug addiction that propose physical dependence as necessary for the rewarding effects of opioids.     

哺乳仔猪外周血5-羟色胺的合成与代谢研究

[目的]探讨哺乳仔猪外周血5-羟色胺的合成与代谢随日龄变化的规律。[方法]选用15只0、5和15日龄的英系大白猪为试验动物,采用反相高效液相色谱——紫外检测法对其外周血血清中L-Trp、5-HT和5-HIAA的含量进行测定。[结果]仔猪初生时L-Trp的含量为（16.92±1.74）μmol/L,5日龄时为（59.94±10.88）μmol/L,15日龄时为（70.42±6.48）μmol/L;仔猪初生时5-HT的含量为（12.85±1.79）μmol/L,5日龄时为（4.81±2.05）μmol/L,15日龄时为（5.49±1.09）μmol/L;代谢产物5-HIAA在各日龄仔猪血清中均未检出。[结论]随日龄增加,哺乳仔猪外周血L-Trp的含量显著增加（P〈0.05）,而5-HT的含量与L-Trp-5-HT通路转化率在初生时最高（P〈0.05）,此后趋于稳定（P〉0.05）。     

Micelle formation between 5-hydroxytryptamine and adenosine triphosphate in platelet storage organelles

As judged by analytical ultracentrifugation, 5-hydroxytryptamine and adenosine-5'-triphosphate form micelles in artificial mixtures and also in storage organelles containing 5-hydroxytryptamine of blood platelets of rabbits. Their average apparent molecular weights depend on the concentration and on the molar ratio of the two constituents. The 5-hydroxytryptamine and adenosine triphosphate of these 5-hydroxytryptamine organelles may be stored in vivo together as micelles with apparent molecular weights of several hundred thousands or more.     

Forchheimer方程对物理参量的连续依赖性

研究了一类Forchheimer方程的解的结构稳定性问题,通过证明得到:Forchheimer方程的解对粘性系数γ是连续依赖的,也就是说,当γ变化很小时,其解的变化也很小.     

红花籽粕中5-羟色胺衍生物的提取工艺

[目的]探究红花籽粕中5-羟色胺衍生物的回流提取工艺。[方法]经过单因素试验,确定乙醇为最适合提取溶剂,在单因素试验的基础上,通过正交试验确定提取过程中3个主要因素的最佳值。[结果]结果表明:原料粒度在20目以上可以有较好的提取效果;提取过程中3个主要因素的最佳值:提取温度为80℃,提取时间为3 h,液料比为3∶1。在此条件下,5-羟色胺衍生物的提取得率达到了2.592mmol/g。[结论]液料比对试验结果影响最大,其次为提取温度和提取时间。     

Inhibition of morphine tolerance and dependence by the NMDA receptor antagonist MK-801.

The N-methyl-D-aspartate (NMDA) subtype of the glutamate receptor is an important mediator of several forms of neural and behavioral plasticity. The present studies examined whether NMDA receptors might be involved in the development of opiate tolerance and dependence, two examples of behavioral plasticity. The noncompetitive NMDA receptor antagonist MK-801 attenuated the development of tolerance to the analgesic effect of morphine without affecting acute morphine analgesia. In addition, MK-801 attenuated the development of morphine dependence as assessed by naloxone-precipitated withdrawal. These results suggest that NMDA receptors may be important in the development of opiate tolerance and dependence.