Enhancing Visible-Light Photocatalysis with Pd(II) Porphyrin-Based TiO2 Hybrid Nanomaterials: Preparation, Characterization, ROS Generation, and Photocatalytic Activity

Novel hybrid TiO2-based materials were obtained by adsorption of two different porphyrins on the surface of nanoparticles-commercially available 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and properly modified metalloporphyrin-5,10,15,20-tetrakis(2,6-difluoro-3-sulfophenyl)porphyrin palladium(II) (PdF2POH). The immobilization of porphyrins on the surface of TiO2 was possible due to the presence of sulfonyl groups. To further elevate the adsorption of porphyrin, an anchoring linker-4-hydroxybenzoic acid (PHBA)-was used. The synthesis of hybrid materials was proven by electronic absorption spectroscopy, dynamic light scattering (DLS), and photoelectrochemistry. Results prove the successful photosensitization of TiO2 to visible light by both porphyrins. However, the presence of the palladium ion in the modifier structure played a key role in strong adsorption, enhanced charge separation, and thus effective photosensitization. The incorporation of halogenated metalloporphyrins into TiO2 facilitates the enhancement of the comprehensive characteristics of the investigated materials and enables the evaluation of their performance under visible light. The effectiveness of reactive oxygen species (ROS) generation was also determined. Porphyrin-based materials with the addition of PHBA seemed to generate ROS more effectively than other composites. Interestingly, modifications influenced the generation of singlet oxygen for TPPS but not hydroxyl radical, in contrast to PdF2POH, where singlet oxygen generation was not influenced but hydroxyl radical generation was increased. Palladium (II) porphyrin-modified materials were characterized by higher photostability than TPPS-based nanostructures, as TPPS@PHBA-P25 materials showed the highest singlet oxygen generation and may be oxidized during light exposure. Photocatalytic activity tests with two model pollutants-methylene blue (MB) and the opioid drug tramadol (TRML)-confirmed the light dose-dependent degradation of those two compounds, especially PdF2POH@P25, which led to the virtually complete degradation of MB.

‘The Body Keeps the Score’ Revisited: Changes in Lipid Levels and Coronary Disease Risk in Army Veterans Suffering from Chronic PTSD

Aim:

To assess possible differences in plasma cholesterol, triglycerides, LDL-C, HDL-C, VLDLC, Index of arteriosclerosis and Established risk factor for arteriosclerosis and 10 year risk of coronary disease between veterans with combat experience with PTSD and veterans with combat experience without PTSD. To compare and analyze differences between groups in socio-demographic characteristics, trauma exposure, coping strategies and quality of life.

Method:

Plasma lipid parameters were determined and risk factors calculated for 50 subjects in the PTSD group and 50 subjects in the non-PTSD group. Groups were homogenized in gender, age, BMI, smoking status and somatic or psychiatric co-morbid disorders or the use of medications influencing blood lipid levels. Trauma exposure, coping strategies and quality of life were assessed with referenced psychometric instruments, socio-demographic characteristics with use of questionnaire.

Results:

Subjects in the PTSD group had significantly higher levels of all plasma lipid parameters except for HDL-C that was significantly lower. Risk factors were significantly higher in PTSD group. There was no significant difference in indices of exposure to combat trauma. Secondary traumatization was significantly more frequent in PTSD group. There were significant differences in socio-economic parameters, quality of life assessment and repertoire of coping strategies.

Conclusions:

The results of this study provide further evidence for the onnection of chronic PTSD and blood lipids abnormalities and cardiovascular risk factors. The results indicate the importance of posttraumatic environment factors and coping strategies for the occurrence and persistence of PTSD.

A closer look at combining data among a small number of binomial experiments

In a regulatory environment, the regulators and the regulated may not be able to agree on the use of subjective prior information for a clinical trial. The use of a data-based prior offers a greater possibility for agreement, however, the degree of importance given to the prior data may still be contentious. The use of a hierarchical model to link the prior data and the current trial is shown to provide a relatively objective method for assigning weight to the prior data. Using a series of examples combining two binomial experiments, the effect of a hierarchical model on estimating rates, on the degree to which data is combined and on hypothesis testing is illustrated. In addition, the phenomenon in which combining data reduces the precision is explained. Simpler models based on finite mixtures of beta distributions are shown to work as well as the more computationally intensive, continuous mixtures. Lastly, an example combining three concurrent studies is illustrated. Published in 2001 by John Wiley & Sons, Ltd.

Influence of adenosine receptor agonists and antagonists on amphetamine-induced stereotypy in rats

The influence of adenosine receptor agonists and antagonists on amphetamine-induced stereotypy was examined in male Wistar rats. Adenosine A2 receptor agonists CGS 21680 (0.5-2 mg/kg ip) and a non-specific A2/A1 receptor agonist NECA (0.05-0.1 mg/kg ip) attenuated in a dose dependent manner amphetamine-induced stereotypy (2 mg/kg sc). CPA as specific agonist of adenosine A1 receptors counteracted this stereotypy, but only in a narrow range of doses (0.1-0.2 mg/kg ip). Adenosine A2A receptor antagonist, DMPX (3 and 6 mg/kg ip) potentiated stereotypy induced by either subthreshold dose of amphetamine 0.5 mg/kg or a high one 2 mg/kg. A non-selective adenosine receptor antagonist, caffeine (10 mg/kg ip) potentiated effect of low dose of amphetamine, but only in a dose of 20 mg/kg ip increased stereotypy induced by 2 mg/kg ip of amphetamine. A selective adenosine A1 receptor antagonist CPT (1 and 3 mg/kg ip) was ineffective in reversing amphetamine-induced stereotypy. These results confirm the existence of adenosine-dopamine interactions in the brain, and the suggestions that A2 adenosine receptor agonists may have antipsychotic properties.

Model-based small area estimates of overweight prevalence using sample selection adjustment

Using a hierarchical model with an adjustment for sample selection, we estimate the overweight prevalence for adults, by states, using data from the Third National Health and Nutrition Examination Survey (NHANES III). A two-stage hierarchical model was selected to account for geographic variability of outcomes and to model possible overdispersion of estimates due to cluster sampling. We compare our model-based estimates with design-based estimates at the national level and obtain excellent agreement. We also provide a check of our model at the state level by comparing estimates with design-based and synthetic estimates.

Haloperidol-induced catalepsy is influenced by adenosine receptor antagonists

Cataleptogenic effects of haloperidol (1 mg/kg i.p.) in rats was antagonized by caffeine and theophylline (10-50 mg/kg i.p.), and by selective adenosine A2 receptor antagonist (3,7-dimethyl-1-propargylxanthine) (3 and 6 mg/kg i.p.). Selective A1-adenosine receptor antagonist (8-cyclopentyltheophylline) (1.5 and 3 mg/kg i.p.) was not able to reduce this effect of haloperidol. These results confirm the antagonistic interaction between adenosine A2A and dopamine D2 receptors, and suggest the involvement of adenosine A2 receptors in the mechanisms of catalepsy.

Influence of adenosinergic drugs on ethanol withdrawal syndrome in rats

The influence of adenosine, its analogs: (-)N6-(R-phenylisopropyl)-adenosine (R-PIA), N6-cyclohexyladenosine (CHA), 5-(N-ethylcarboxamido)-adenosine (NECA), adenosine uptake inhibitor-dipyridamole, and theophylline and caffeine (adenosine receptor antagonists) on ethanol withdrawal syndrome was investigated in rats. Adenosine (100 mg/kg ip), all adenosine analogs and dipyridamole (30 mg/kg ip) reduced the number of rats in which audiogenic convulsions appeared. Caffeine and theophylline (5-25 mg/kg ip) did not influence significantly the audiogenic seizures, but they antagonized the depressing effects of adenosine analogs on these withdrawal symptoms. The results suggest that adenosine mechanisms in the brain may be implicated in the development of ethanol withdrawal syndrome.

Purinergic receptors

The aim of the present paper was characterization of purinergic receptors specific for nucleotides (P2) and nucleosides (P1). Their subclassification, distribution and functions have been briefly described.

Chemical and pharmacological properties of new tetrahydropyrimido-[2,1-f]-purines

Following a research program on piperazinoalkyl-substituted tricyclic purines, a number of N-9-aryl(alkyl)-piperazinopropyl substituted tetrahydropyrimido-[2,1-f]-purines were synthesized and tested pharmacologically with respect to their influence on the central nervous system. Two of the new compounds induced hypothermia and decreased the spontaneous locomotor activity of mice.

The influence of new 9-(omega-[4-(2-pyrimidinyl)-1-piperazinyl]alkyl) pyrimidino[2,1-f]purines on the central nervous system

Synthesis and the results of preliminary pharmacological evaluation of four new 9-substituted pyrimidino[2,1-f]purines, containing pyrimidinyl-piperazine substituent are described. Some of these substances induced hypothermia, antagonism of amphetamine action and neurotoxic effects. All compounds had weaker activity on the central nervous system than previously studied compounds containing phenyl-piperazine substituent.

The influence of naloxone on the effects of adenosine receptor agonists in analgesic tests and binding studies

Naloxone (1 mg/kg ip) reduced analgesic effect of R-phenylisopropyladenosine (R-PIA-0.2 mg/kg sc) in hot plate and tail-immersion tests in mice and in tail-immersion test in rats. Also the effect of 2-chloroadenosine (2-CADO-2 mg/kg sc) was significantly reduced by naloxone in mice in both nociceptive tests. Naloxone induced partial reduction of analgesic effects of 5'-N-ethylcarboxamideadenosine (NECA-0.02-0.05 mg/kg sc) in mice and rats. Binding studies revealed that the affinity of adenosine agonists (R-PIA and NECA) to opioid receptors was about 5000 times weaker than the corresponding affinity of naloxone.

Bayesian predictive inference for units with small sample sizes. The case of binary random variables

The National Health Interview Survey is designed to produce precise estimates for the entire United States but not for individual states. In this study, Bayesian predictive inference is used to provide point estimates and measures of variability for the desired finite population quantities. The investigation reported here concerns binary random variables such as the occurrence of at least one doctor visit within the past 12 months. The specification is hierarchic. First, for each cluster, there is a separate logistic regression relating a patient's probability of a doctor visit with his or her characteristics. Second, there is a multivariate linear regression linking the (cluster) regression parameters to covariates measured at the cluster level. A fully Bayesian analysis is carried out; this technique provides gains over synthetic estimation and conventional randomization-based analysis. The reported approach is potentially useful for any situation when the sample size associated with a unit of interest (e.g., a hospital or small geographic area) is too small to permit satisfactory inference using only the data from that unit.

Agonists and antagonists of adenosine receptors and morphine withdrawal syndrome in rats

The compounds activating adenosine system alleviated morphine withdrawal syndrome (the number of escape attempts and body shakes) in rats. Body shakes were decreased mostly by N-ethylcarboxamidoadenosine, cyclohexyladenosine, dipyridamole and 2-chloroadenosine, while R-phenylisopropyladenosine very strongly decreased the number of escape attempts. Adenosine receptor antagonists (caffeine and theophylline) increased the number of escape attempts in morphine-dependent rats. Caffeine (10 mg/kg), administered preventively, antagonized the inhibitory effects of adenosine analogs. These results suggest the existence of relation between opioid receptors and the adenosine system.

Synthesis and preliminary pharmacological assessment of novel 9-alkylamino substituted pyrimidino-[2,1-f]-purines

Two series of N9-alkylaminomethyl-, alkylpiperazino-, alkylpiperidino-substituted 1,3-dimethyl-(hexahydropyrimidino)- and (tetrahydropyrimidono)-[2,1-f]-purines were prepared and their physicochemical and pharmacological properties were described. The most active in central nervous system tests were the compounds with phenylpiperazinealkyl substituent i.e. 1,3-dimethyl-2,4-dioxo-9-[N1N4-(phenyl)-piperazinopropyl]-1, 3,6,7,8,9- hexahydropyrimidino-[2,1-f] purine 6a and its butyl and isobutyl homologs 9 and 12. The compounds depressed statistically significantly spontaneous locomotor and amphetamine activity and showed sedative, analgetic and hypothermizing properties.

Interaction of adenosine analogs with morphine in analgesic tests

The effect of selective adenosine receptor agonists on nociceptive responses of mice and rats and on morphine analgesia was investigated. All compounds used: phenylisopropyladenosine (R-PIA), adenosine ethylcarboxamide (NECA), cyclohexyladenosine (CHA) and 2-chloroadenosine (2-CADO) exhibited antinociceptive action in mice and rats in the hot-plate (56 degrees C) and tail-immersion (52 degrees C) tests. R-PIA, CHA and NECA potentiated the antinociceptive action of morphine in mice, and R-PIA and NECA--in rats. 2-CADO did not affect the morphine action in the tests.

Synthesis and preliminary pharmacological assessment of novel 9-substituted pyrimidino-[2,1-f]-purines

Synthesis, chemical properties and results of preliminary pharmacological evaluation of several new 9-substituted pyrimidino-[2,1-f]-purines are described. The most interesting was 1,3-dimethyl-2,4,8-trioxo-9-[gamma-N1-(N4-C6H5)-piperazynopropy l]-1,3,6,7-tetrahydro-9H-pyrimidino-[2,1-f]-purine (compound 4a), which exerted strong sedative, hypothermizing and cataleptogenic action and possessed some anti-amphetamine and anti-apomorphine properties.

Synthesis and preliminary pharmacological assessment of novel gamma-hydroxybutyric acid derivatives

Synthesis and properties of new N-substituted amides of alpha-(1,1-ethylenedioxy)-ethyl-gamma-hydroxybutyric acid are described. The compounds were obtained by aminolysis of 3-(1,1-ethylenedioxy)-ethyltetra-hydrofuran-2-on with primary alkylarylamines. Preliminary pharmacological assessment revealed that the compounds exert weaker influence on the central nervous system than the reference gamma-hydroxybutyric acid. Three of the novel compounds offered some protection against pentetrazole-induced tonic seizures in mice.

The effect of adenosine receptor agonists on analgesic effects of morphine

The effect of adenosine, S-phenylisopropyladenosine (S-PIA) and dipyridamole (an adenosine reuptake inhibitor) on the analgesic action of morphine in mice and rats was investigated in the hot-plate (56 degrees C) and tail immersion (52 degrees C) tests. Adenosine, 50 and 100 mg/kg, induced analgesia in mice and rats in the hot-plate test and potentiated the action of morphine (particularly in mice). The analgesic effects of adenosine were completely abolished by caffeine (10 mg/kg in mice and rats), and partially inhibited by naloxone (1 mg/kg, only in mice). S-PIA given alone (0.6 mg/kg) produced in mice some analgesic effect in the hot-plate test: the effect was abolished by caffeine and partially by naloxone. The effect of S-PIA on the action of morphine depends on the dose and the animal species. Dipyridamole alone did not affect the reactivity of animals in tests for analgesia, but potentiated the action of morphine.

Synthesis and preliminary pharmacological screening of some 8-substituted methylxanthines

Methods of synthesis, chemical properties and results of preliminary pharmacological screening for 8-amino substituted derivatives of caffeine (1-3) and 7,8-disubstituted derivatives of 8-aminotheophylline (8-12) have been described. The compounds show weak sedative and antidepressive activity and some of them (2, 10, 12) also small antinociceptive effect.

The effect of methylxanthines on morphine analgesia in mice and rats

The influence of various doses of caffeine and theophylline on analgesic effect of morphine was tested in mice and rats in the hot plate and tail immersion tests. Caffeine in rats potentiated the morphine analgesia in both tests in a dose-dependent manner. In mice the caffeine-morphine interaction was biphasic: lower caffeine doses (10 and 25 mg/kg) inhibited, while higher (75 and 100 mg/kg) potentiated the analgesic effects of morphine. Theophylline interacted with morphine in a manner similar to that of caffeine.

Cross-tolerance between morphine and ethanol and their antinociceptive effects

Morphinization of mice (37.5 mg morphine) and rats (75 mg) with subcutaneously implanted pellets has resulted in tolerance to the antinociceptive effect of morphine, measured in the tail-immersion test. All animals also developed cross-tolerance to the analgesic effects of ethanol (2.8 g/kg intraperitoneally for mice, per os for rats). These results suggest a commonality between morphine and ethanol antinociceptive action.

The influence of histamine receptor antagonists on antinociceptive action of narcotic analgesics

The influence of some antagonists of histamine receptors on morphine-, fentanyl-, and pentazocine-induced analgesia was studied in rats and mice. H1-receptor antagonists (benzhydramine mepyramine) potentiated analgesic action of morphine and fentanyl. Given alone in high doses they also induced a naloxone non-reversible analgesia. Analgesic effects of pentazocine were not changed by benzhydramine and mepyramine. H2-receptor antagonist-cimetidine enhanced also analgesia induced by morphine and fentanyl in rats, but it either increased (after icv injection of 50 micrograms) or decreased (after icv injection of 100 micrograms) the action of pentazocine. Thus, H1 and H2 antagonists potentiate the antinociceptive effects of morphine and fentanyl but the action of pentazocine is not changed by H1 antagonists and is affected in an inconsistent manner by a H2 antagonist cimetidine. It seems that the potentiating effect of H-antagonists is related to the opioid mu receptors.

The influence of gabaergic system on cataleptogenic action of analgesics and haloperidol

The effect of agonists and antagonists of the gabaergic system on catalepsy induced by morphine, fentanyl and haloperidol was investigated in the rat. The compounds inhibiting gabaergic neurotransmission, bicuculline and picrotoxin, given in subconvulsive doses (0.1-0.5 mg/kg) in general do not evidently affect cataleptogenic effects of the analgesics and haloperidol. Of the gabaergic agonists muscimol (0.2-0.5 mg/kg) potentiates only the haloperidol catalepsy, without changing the action of analgesics. Aminooxyacetic acid (AOAA, 25 mg/kg) markedly potentiated the catalepsy brought about by analgesics, while weakly and insignificantly facilitated that induced by haloperidol. Baclofen in a low dose (1 mg/kg) antagonized the action of haloperidol and fentanyl, whereas in higher doses (2-8 mg/kg) it did not visibly affect the action of any investigated drugs. Thus the action of gabaergic agonists and antagonists on the analgesic and haloperidol catalepsy varies, depending on the dose and kind of the agent affecting the gabaergic system.

Is the brain histamine involved in cataleptogenic action of analgesics and haloperidol?

L-Histidine, histamine ivc, and amodiaquine (inhibitor of histamine catabolism) enhanced catalepsy induced by morphine, codeine and fentanyl. Haloperidol catalepsy was increased only by ivc histamine. H1 (but not H2) receptor antagonists have shown anticataleptic effect in the action of analgesics and haloperidol.

Central action of narcotic analgesics. VIII. The effect of dopaminergic stimulants on the action of analgesics in rats

We investigated the influence of apomorphine, amphetamine, amantadine, dimethylaminoadamantane, nomifensine, ergometrine and beta-phenylethylamine on cataleptogenic and antinociceptive action of analgesics in rats. Nomifensine, apomorphine, beta-phenylethylamine, amantadine and ergometrine antagonized the catalepsy induced by morphine and codeine. Catalepsy induced by fentanyl was depressed only by nomifensine and apomorphine. Amphetamine only slightly antagonized the analgesic-induced catalepsy and the effects were not dose-dependent. Dimethylaminoadamantane did not antagonize catalepsy at all. Antinociceptive action of morphine and codeine was antagonized by apomorphine and amphetamine. Ergometrine counteracted the action of morphine, and beta-phenylethylamine decreased the action of pentazocine. The results suggest that: 1. There are differences in the mechanism of cataleptogenic action of the opiates (morphine and codeine) and fentanyl; 2. Catalepsy after analgesia differs from the catalepsy produced by neuroleptics in respect of interaction with such drugs as amphetamine, apomorphine or dimethylaminoadamantane. Analgesic-induced catalepsy seems to depend on the presynaptic inhibition of dopaminergic neurotransmission; 3. Stimulation of the central dopaminergic system in rat brain either does not change or weakly antagonizes the action of analgesics in the hot plate test.

Central action of narcotic analgesics. VI. Further studies on the participation of serotonin in the action of analgesics

The effects of agents changing the cerebral serotonin (5-HT) level on the action of morphine, codeine, fentanyl and pentazocine were tested in rats with the tests of catalepsy and analgesia (hot plate). In addition, the effect of analgesics of the level and turnover of cerebral 5-HT was studied. Depression of the cerebral level of 5-HT usually antagonized the behavioral effects of analgesics, but the effect varied with the agent depressing the 5-HT level. The serotonergic influences in catalepsy seem to be more pronounced than in analgesia. An increase in the cerebral level of 5-HT may potentiate the analgesic and prolonged the cataleptogenic effects of some drugs (morphine and pentazocine), not affecting the effect of others (fentanyl, codeine). The potentiation by morphine of the turnover of cerebral 5-HT in rats is not a common property of analgesics agents.

The influence of 5-HT receptor blocking agents on the behavioral effects of analgesics in rats

The influence of methergoline, methysergide, mianserine, cyproheptadine, and pizotifen on catalepsy induced by morphine, codeine, and fentanyl, and antinociception induced by these three drugs and by pentazocine was studied in rats. Methergoline dose-dependently reduced catalepsy induced by these three drugs. Methysergide abolished only morphine catalepsy, while mianserine significantly reduced the effect of morphine and codeine. Cyprohepatide and pizotifen did not modify the cataleptic effect of the three analgesics used. Antinociceptive action of morphine, codeine, fentanyl, and pentazocine, measured by the hot plate method, was not influenced or changed differentially by any serotonin receptor blocking compounds. One may conclude that catalepsy induced by morphine is, in general, antagonized by serotonin receptor blockade, but this does not concern all narcotic analgesics. In the antinociceptive effects of drugs used, the serotonergic influence seems to play a less important role than in catalepsy.

Anticataleptic action of psychostimulating drugs and serotonin in brain

The effects of drugs changing serotonin activity in rats were studied observing changes in the anticataleptic action of amphetamine and ephedrine. It was observed that: 1) parachlorophenylalanine prolonged the anticataleptic action of ephedrine and, in part also, that of amphetamine, 2) methysergide alone exerted an anticataleptic effect and enhanced somewhat the same effect of both psychostimulating drugs used, 3) d, 1-tryptophan increased the intensity of catalepsy and reduced very significantly or abolished completely the anticataleptic action of ephedrine and amphetamine. These results support the view that the serotonin system exerts a suppressing effect on the central effects resulting from stimulation of catecholamine dependent functions.

Central action of narcotic analgesics. Part IV. Noradrenergic influences on the activity of analgesics in rats

The effect of clonidine, naphazoline and xylometazoline on analgesia induced by morphine, codeine, fentanyl and pentazocine, and on cataleptic effect of morphine, codine and fentanyl was studied in rats. The biochemical assays on the influence of four analgesics on the brain concentration and turnover of noradrenaline (NA) were also performed. It was found that three drugs stimulating central NA receptors failed to affect the analgesic ED50 of all antinociceptive agents and they enhanced catalepsy induced by morphine and fentanyl. Codeine catalepsy was increased by clonidine and decreased by naphazoline and xylometazoline. The brain concentration of NA was not changed by morphine and fentanyl, but one of the doses of codeine (45 mg/kg) slightly enhanced it. Pentazocine dose-dependently decreased the brain level of NA. The rate of NA turnover was not altered by analgesics except for the higher dose of fentanyl (0.2 mg/kg) following which the disappearance of NA from the brain was diminished. The results are discussed in the light of various and non-uniform data from the literature. It is suggested that in rats the brain NA plays a less important function than the other monoamines in the behavioural activity of potent analgesics.

Central action of narcotic analgesics. II. Locomotor activity and narcotic analgesics

The effect of morphine, codeine, fentanyl and pentazocine on locomotor activity of rats and mice and open-field performance of rats were tested. All the analgesics tested produced a depressive action in the rat. In mice a depressive action was produced by pentazocine and codeine. Fentanyl increased the exploratory and basal locomotor activity of mice. Morphine increased the exploratory activity, but, given at doses of 2.5 and 10 mg/kg decreased the basal locomotor activity. The increase of locomotor activity in mice by morphine and fentanyl is caused by an indirect stimulation of catecholamine receptors.

Central action of narcotic analgesics. I. Catalepsy and stereotypy in rats and narcotic analgesics

The action of four analgesics, belonging to various pharmacological groups (morphine, codeine, fentanyl, pentazocine), was investigated in rats in tests for catalepsy and stereotypy, the tests depending on dopaminergic brain mechanisms. Interactions of the analgesics with a number of compounds known to affect dopaminergic brain functions in tests of catalepsy and stereotypy were also studied. In some experiments nalorphine, an antagonist of narcotic analgesics, was used. Morphine, codeine and fentanyl produced catalepsy, while pentazocine, at doses up to 60 microgram/kg, did not produce this effect. Reserpine, 2 mg/kg 3 hr before drugs, potentiated catalepsy produced by analgesics, while haloperidol, 0.2 mg/kg, 2 hr earlier, did not influence morphine and codeine catalepsy, but moderately potentiated fentanyl-induced catalepsy. alpha-methyl-p-tyrosine potentiated the cataleptogenic action of fentanyl and codeine, and also, less markedly, the action morphine. D-amphetamine (2.5-10 mg/kg) and apomorphine (5 mg/kg) moderately antagonized the catalepsy induced by analgesics, while atropine did not affect it. Nalorphine, 5 mg/kg, effectively abolished the catalepsy produced by narcotic analgesics, but did not affect that produced by neuroleptics. Morphine, codeine and fentanyl slightly inhibited apomorphine stereotypy, and evidently antagonized stereotypy produced by amphetamine. Pentazocine did not affect or slightly potentiated the both types of stereotypy. It is concluded that morphine, codeine and fentanyl, in contrast to pentazocine, inhibit behavioral activities depending on central dopaminergic functions in the rat. The mechanism of this action is most probably indirect, and seems to be related to the dopaminergic presynaptic functions.

The role of 5-HT in the mechanism of amphetamine action

AM stereotypy-inducing action was potentiated in rats in proportion to the previously administered doses of pCPA (3 X 100, 3 X 150 or 3 X 200 mg/kg); however, the dose of 3 X 300 mg/kg pCPA brought about the decrease in stereotypy. Reserpinized rats exhibited also increased AM stereotypy but of shorter duration. AM hyperactivity in mice was potentiated also by the pretreatment with pCPA but this action occurred within a further phase of observation (30 min after the injection). It seems then that 5-HT may be a factor suppressing the stimulating action of AM.

Comparison of central effects of noradrenaline and dopamine injected into the lateral brain ventricle in rats

Noradrenaline and dopamine injected into the lateral brain ventricle exerted a significant effect on the behavior of rats. Both amines caused a slight rise in the basic locomotor activity which was significantly increased in the animals with inhibited monoamine oxidase activity. Besides that, they suppressed the behavior of rats in the open-field test, inhibited the conditioned avoidance response, decreased body temperature and increased amphetamine-induced motor hyperactivity. Noradrenaline, in contrast to dopamine, changed the intensity of amphetamine-induced stereotypy and prolonged the action of hypnotics. The central action of both catecholamines (in higher doses especially) seemed to have a biphasic course: in the first phase after administration depression was observed which was more pronounced after noradrenaline administration, in the second phase a stimulating effect b