Catalepsy induced by morphine or haloperidol: effects of apomorphine and anticholinergic drugs

1976 ◽  
Vol 54 (4) ◽  
pp. 516-519 ◽  
Author(s):  
C. Ezrin-Waters ◽  
P. Muller ◽  
P. Seeman

To investigate the extent of cholinergic involvement in opiate-induced catalepsy, the effects of three anticholinergic drugs were studied on morphine-induced catalepsy. Haloperidol-induced catalepsy was also examined. Maximum catalepsy in rats was obtained with 30 mg/kg morphine or 3 mg/kg haloperidol. The anticholinergic drugs atropine, benztropine, and scopolamine were unable to antagonize morphine-induced catalepsy, yet readily antagonized haloperidol-induced catalepsy. Low doses of apomorphine (7.5 mg/kg), on the other hand, readily antagonized morphine catalepsy, but 13-fold higher doses of apomorphine were needed to block haloperidol-induced catalepsy. The results are compatible with the idea that catalepsy can be mediated via the striatum or the amygdala; morphine–dopamine antagonism may occur in the amygdala, whereas morphine–dopamine–cholinergic interactions occur in the striatum.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Salah A. Sheweita ◽  
Mona Wally ◽  
Mostafa Hassan

Erectile dysfunction (ED) is a major health problem and is mainly associated with the persistent inability of men to maintain sufficient erection for satisfactory sexual performance. Millions of men are using sildenafil, vardenafil, and/or tadalafil for ED treatment. Cytochrome P450s (CYPs) play a central role in the metabolism of a wide range of xenobiotics as well as endogenous compounds. Susceptibility of individuals to the adverse effects of different drugs is mainly dependent on the expression of CYPs proteins. Therefore, changes in activities of phase I drug-metabolising enzymes [arylhydrocarbon hydroxylase (AHH), dimethylnitrosamine N-demethylase (DMN-dI), 7-ethoxycoumarin-O-deethylase (ECOD), and ethoxyresorufin-O-deethylase ((EROD)] and the protein expression of different CYPs isozymes (CYP1A2, CYP2E1, CYP2B1/2, CYP3A4, CYP2C23, and CYP2C6) were determined after treatment of male rats with either low or high doses of sildenafil (Viagra), tadalafil (Cialis), and/or vardenafil (Levitra) for 3 weeks. The present study showed that low doses of tadalafil and vardenafil increased DMN-dI activity by 32 and 23%, respectively. On the other hand, high doses of tadalafil, vardenafil, and sildenafil decreased such activity by 50, 56, and 52%, respectively. In addition, low doses of tadalafil and vardenafil induced the protein expression of CYP2E1. On the other hand, high doses of either tadalafil or sildenafil were more potent inhibitors to CYP2E1 expression than vardenafil. Moreover, low doses of both vardenafil and sildenafil markedly increased AHH activity by 162 and 247%, respectively, whereas high doses of tadalafil, vardenafil, and sildenafil inhibited such activity by 36, 49, and 57% and inhibited the EROD activity by 39, 49, and 33%, respectively. Low and high doses of tadalafil, vardenafil, and sildenafil inhibited the activity of NADPH-cytochrome c reductase as well as its protein expression. In addition, such drugs inhibited the expression of CYP B1/2 along with its corresponding enzyme marker ECOD activity. It is concluded that changes in the expression and activity of phase I drug-metabolising enzymes could change the normal metabolic pathways and might enhance the deleterious effects of exogenous as well as endogenous compounds.


1987 ◽  
Vol 2 (4) ◽  
pp. 296-305 ◽  
Author(s):  
P. Boyer ◽  
A.J. Puech

SummaryAs emphasized by Lecrubier in 1980, the major finding of the last thirty years of classical neuroleptic use in schizophrenia is not that they are antischizophrenic or antipsychotic agents, but that they act on positive symptoms whatever the cause. There is now a widely accepted attribution of this kind of therapeutic property to the post-synaptic dopaminergic blockade induced by most of the neuroleptics when administered at high doses. On the other hand, during the last decade, various authors have reported clear evidence for a disinhibitory action of some neuroleptics when used at low doses. From a clinical point of view, the literature on the therapeutic action of low doses of neuroleptics seems quite controversial. In order to assess the exact determinants for clinical activity of neuroleptics (such as patient type, selected substances, administered doses) two series of independent controlled studies were conducted.First series of studies: active drugs at low and high doses in schizophrenic patients(Tables 1 to 6)The first study was designed to assess the change of negative symptoms under low doses of neuroleptics. Sixty-two patients meeting the DSM III criteria of schizophrenia (subtypes: disorganized, catatonic or residual) were randomly assigned after a three-week washout period to six weeks’ treatment with either amisulpride (50 to 300 mg/day) or fluphenazine (2 to 12 mg/day), administered in keeping with a flexible dosage schedule. All patients had to meet the Andreasen criteria for negative symptoms (at least two of the following components had to be checked as present: anhedonia, alogia, affective flattening, avolition-apathy, attentional impairment). None of the patients presented one of the positive components to a marked degree: hallucinations, delusions, bizarre behavior, positive formal thought disorders. The evolution of symptomatology was assessed by means of the Brief Psychiatric Rating Scale (B.P.R.S.) and an ad hoc defective symptoms scale (D.S.A.S.), the sensitivity and reliability of which was previously tested in our department. The results show that the two groups (amisulpride versus fluphenazine) were initially highly comparable. Negative symptoms were severe, as evidenced by the D.S.A.S. scores, and by the presence of three items of the A6 criterion of the DSM III. The final global clinical assessment and the final D.S.A.S. scores both showed a significant improvement, with no statistically significant difference between the two treatments. Nevertheless, the scores of the “anergia” and “anxiety-depression” factors of the B.P.R.S. showed a significantly greater improvement in the amisulpride group.The second study, complementary to the first, aimed to check the efficacy of high doses of amisulpride on the productive symptoms of schizophrenia. In this case, only the B.P.R.S. was used due to the good correlation of this scale with the global severity of the positive symptomatology. After three weeks of treatment, consisting either of amisulpride at a high, flexible dosage (800 to 1200 mg/day) or of haloperidol (20 to 30 mg/day), each of the two groups of twenty patients showed a significant improvement. In particular, the “thought disorders” factor of the B.P.R.S. (which unfortunately does not correspond exactly to the “formal thought disorder” component of the Andreasen positive symptoms scale - S.A.P.S.) was greatly improved in both groups. Evolution of the other symptoms was however identical in the two groups.Second series of studies: active drugs versus placebo in schizophrenia(Figures 1 to 6)As we know, dopaminergic blocking agents are able to induce negative symptomatology. Consequently, to separate the secondary syndrome from the true deficit, a longer washout period than that previously described has to be imposed. On the other hand, the longitudinal course of schizophrenia must be taken into account for correct interpretation of changes in symptomatology; for example, patients with negative symptoms may abruptly present productive episodes, in particular during the neuroleptic withdrawal period. For optimal control of these two variables (natural history of the disease, the blunting effect of neuroleptics), 90 patients presenting either or both subtypes of schizophrenia were selected and included in a two-step, double-blind, controlled study. Patients with negative symptoms underwent a six-week washout period, after which they were treated either with low doses of amisulpride (100 or 300 mg/day) or a placebo. Patients with initial positive symptoms received mandatory high doses of amisulpride. According to the protocol, negative patients presenting productive symptoms during the washout period were to be systematically assigned to the highdose group. First results concerning 38 patients with a predominant negative symptomatology are presented here. A very clear improvement can be shown both for the SANS global mean score and for the sum of global ratings in the groups treated with low doses of amisulpride compared to the placebo group. The scores of the alogia, blunted affect and attentional impairment subscales decrease dramatically as well with the active drug.


2001 ◽  
Vol 44 (2) ◽  
pp. 77-79 ◽  
Author(s):  
Jiří Kassa

1. The influence of anticholinergic drugs (atropine, benactyzine, biperiden) on the efficacy of monopyridinium and bispyridinium oximes (HI-6, BI-6, obidoxime, pralidoxime, methoxime) on soman-induced supralethal poisoning was studied in mice. 2. While methoxime combined with benactyzine or biperiden seems to be more efficacious in the elimination of toxic effects of supralethal dose of soman than its combination with atropine, the efficacy of the other oximes studied against soman-induced toxic effects is not significantly influenced by the anticholinergic drug selection. 3. On the other hand, there are big differences in the effectiveness of oximes tested as to their ability to eliminate toxic effects of soman at supralethal doses. 4. The findings support the fact that the choice of acetylcholinesterase reactivator is more important than the anticholinergic drug selection for the effectivenes of antidotal mixture in the case of prophylactic administration of antidotes.


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


Author(s):  
A. V. Crewe

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.


Author(s):  
K.H. Westmacott

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.


2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.


Author(s):  
Stefan Krause ◽  
Markus Appel

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.


2019 ◽  
Vol 50 (2) ◽  
pp. 80-93
Author(s):  
Jort de Vreeze ◽  
Christina Matschke

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.


1961 ◽  
Vol 6 (6) ◽  
pp. 222-223
Author(s):  
Edwin G. Boring
Keyword(s):  

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