Comparison of chloroquine-like molecules for lysosomal inhibition and measurement of autophagic flux in the brain

Measurement of autophagic flux in vivo is critical to understand how autophagy can be used to combat disease. Neurodegenerative diseases have a special relationship with autophagy, which makes measurement of autophagy in the brain a significant research priority. Currently, measurement of autophagic flux is possible through use of transgenic constructs, or application of a lysosomal inhibitor such as chloroquine. Unfortunately, chloroquine is not useful for measuring autophagic flux in the brain and the use of transgenic animals necessitates cross-breeding of transgenic strains and maintenance of lines, which is costly. To find a drug that could block lysosomal function in the brain for the measurement of autophagic flux, we selected compounds from the literature that appeared to have similar properties to chloroquine and tested their ability to inhibit autophagic flux in cell culture and in mice. These chemicals included chloroquine, quinacrine, mefloquine, promazine and trifluoperazine. As expected, chloroquine blocked lysosomal degradation of the autophagic protein LC3B-II in cell culture. Quinacrine also inhibited autophagic flux in cell culture. Other compounds tested were not effective. When injected into mice, chloroquine caused accumulation of LC3B-II in heart tissue, and quinacrine was effective at blocking LC3B-II degradation in male, but not female skeletal muscle. None of the compounds tested were useful for measuring autophagic flux in the brain. During this study we also noted that the vehicle DMSO powerfully up-regulated LC3B-II abundance in tissues. This study shows that chloroquine and quinacrine can both be used to measure autophagic flux in cells, and in some peripheral tissues. However, measurement of flux in the brain using lysosomal inhibitors remains an unresolved research challenge.

Influence of phenothiazine molecules on the interactions between positively charged poly-l-lysine and negatively charged DPPC/DPPG membranes

Phenothiazines are very effective antipsychotic drugs, which also have anticancer and antimicrobial activities. Despite being used in human treatment, the molecular mechanism of the biological actions of these molecules is not yet understood in detail. The role of the interactions between phenothiazines and proteins or lipid membranes has been much discussed. Herein, fourier-transform infrared (FTIR) spectroscopic studies were used to investigate the effect of three phenothiazines: fluphenazine (FPh); chlorpromazine (ChP); and propionylpromazine (PP) on the structures of a positively charged poly-l-lysine (PLL) peptide, a negatively charged dipalmitoylphosphatidylcholine/dipalmitoylphosphatidylglycerol (DPPC/DPPG) membrane, and on the mutual interactions between electrostatically associated PLL molecules and DPPC/DPPG membranes. Phenothiazine-induced alterations in the secondary structure of PLL, the conformational state (trans/gauche) of the hydrocarbon lipid chains, and the hydration of the DPPC/DPPG membrane interface were studied on the basis of amide I' vibrations, antisymmetric and symmetric stretching vibrations of the CH₂ groups of the lipid hydrocarbon chains (ν_sCH₂), and stretching vibrations of the lipid C=O groups (νC = O), respectively. It was shown that in the presence of negatively charged DPPC/DPPG membranes, the phenothiazines were able to modify the secondary structure of charged PLL molecules. Additionally, the effect of PLL on the structure of DPPC/DPPG membranes was also altered by the presence of the phenothiazine molecules.

Control of Mycosphaerella graminicola on wheat seedlings by medical drugs known to modulate the activity of ATP-binding cassette transporters

Medical drugs known to modulate the activity of human ATP-binding cassette (ABC) transporter proteins (modulators) were tested for the ability to potentiate the activity of the azole fungicide cyproconazole against in vitro growth of Mycosphaerella graminicola and to control disease development due to this pathogen on wheat seedlings. In vitro modulation of cyproconazole activity could be demonstrated in paper disk bioassays. Some of the active modulators (amitriptyline, flavanone, and phenothiazines) increased the accumulation of cyproconazole in M. graminicola, suggesting that they reversed cyproconazole efflux. However, synergism between cyproconazole and modulators against M. graminicola on wheat seedlings could not be shown. Despite their low in vitro toxicity to M. graminicola, some modulators (amitriptyline, loperamide, and promazine) did show significant intrinsic disease control activity in preventive and curative foliar spray tests with wheat seedlings. The results suggest that these compounds have indirect disease control activity based on modulation of fungal ABC transporters essential for virulence and constitute a new class of disease control agents.

Synthesis and antitubercular activity of quaternized promazine and promethazine derivatives

Quaternized chlorpromazine, triflupromazine, and promethazine derivatives were synthesized and examined as antitubercular agents against both actively growing and non-replicating Mycobacterium tuberculosis H37Rv. Impressively, several compounds inhibited non-replicating M. tuberculosis at concentrations equal to or double their MICs against the actively growing strain. All active compounds were non-toxic toward Vero cells (IC50 > 128 microM). N-Allylchlorpromazinium bromide was only weakly antitubercular, but replacing allyl with benzyl or substituted benzyl improved potency. An electron-withdrawing substituent on the phenothiazine ring was also essential. Branching at the carbon chain decreased antitubercular activity. The optimum antitubercular structures possessed N-(4- or 3-chlorobenzyl) substitution on triflupromazine.

Influence of classic and atypical neuroleptics on caffeine oxidation in rat liver microsomes

Caffeine is a marker drug for testing the activity of CYP1A2 (3-N-demethylation) in humans and rats. Moreover, CYP3A seems to be essential for its metabolism (8-hydroxylation). In the case of 1-N- and, in particular, 7-N-demethylation of caffeine, apart from CYP1A2, other CYP isoenzymes play a considerable role, probably CYP2B and/or CYP2E1. The aim of the present study was to investigate the influence of two classic neuroleptics (promazine and haloperidol) and two atypical ones (risperidone and sertindole) on cytochrome P-450 activity measured by caffeine oxidation in rat liver microsomes. The obtained results showed that promazine, a phenothiazine neuroleptic with the simplest chemical structure, significantly inhibited 1-N- and 3-N-demethylation and 8-hydroxylation of caffeine via competitive or mixed mechanism (Ki = 21.8, 25.4 and 58.2 microM, respectively). This indicates inhibition by promazine of CYP1A2 (inhibition of 3-N- and 1-N-demethylation), and possibly CYP3A2 (inhibition of 8-hydroxylation), but not of other CYP isoenzymes involved in 7-N-demethylation of caffeine (e.g. CYP2B2 and/or CYP2E1). In contrast to promazine, haloperidol had no effect on the oxidation reactions of caffeine in the applied in vitro metabolic model. The potency of inhibition of caffeine oxidation by risperidone and sertindole resembled rather haloperidol than promazine. Risperidone appeared to be a very weak inhibitor of 3-N-demethylation and 8-hydroxylation (Ki = 202.5 microM) and had no effect on 1-N- and 7-N-demethylation of caffeine. Sertindole was a very poor inhibitor of 1-N- and 7-N-demethylations and 8-hydroxylation pathways of the marker substance (Ki = 132.1, 434.1 and 173.3 microM, respectively); even the observed in vitro inhibition of 3-N-demethylation of caffeine by sertindole (Ki = 68.9 microM) cannot be of practical significance in vivo, considering extremely low pharmacological and therapeutic doses of the neuroleptic. In summary, among the investigated neuroleptics, only promazine showed significant inhibitory activity towards caffeine metabolism in vitro (inhibition of CYP1A2 and possibly CYP3A), which may be of pharmacological and clinical importance in vivo. In contrast to promazine, haloperidol and the investigated atypical neuroleptics had no or very weak effect on caffeine oxidation in vitro,of no in vivo significance. Considering the results of the present and previous studies, it seems highly likely that promazine may cause pharmacokinetic interactions, while atypical neuroleptics seem to be safe in this respect. Moreover, the observed reaction-dependent effects of promazine and sertindole provide indirect evidence that CYP1A2 is not the only isoenzyme important for the metabolism of caffeine, which requires further pharmacological and clinical consideration.

The contribution of cytochrome P-450 isoenzymes to the metabolism of phenothiazine neuroleptics

The aim of the present study was to determine optimum conditions for studying promazine and perazine metabolism in rat liver microsomes, and to investigate the influence of specific cytochrome P-450 inhibitors on 5-sulfoxidation and N-demethylation of these neuroleptics. Based on the developed method, the metabolism of neuroleptics in liver microsomes was studied at linear dependence of product formation on time, and protein and substrate concentrations (incubation time: 10 min; concentration of microsomal proteins: promazine-0.7 mg ml(-1), perazine-0.5 mg ml(-1); substrate concentrations: promazine-25, 40 and 75 nmol ml(-1), perazine-20, 35, 50 nmol ml(-1)). A Dixon analysis of the metabolism of neuroleptics showed that quinine (a CYP2D1 inhibitor), metyrapone (a CYP2B1/B2 inhibitor) and alpha-naphthoflavone (a CYP1A1/2 inhibitor) affected, whereas erythromycin (a CYP3A inhibitor) and sulfaphenazole (a CYP2C inhibitor) did not change the neuroleptic biotransformation. N-Demethylation of promazine was competitively inhibited by quinine (K(i)=20 microM) and metyrapone (K(i)=83 microM), while that of perazine-by quinine (K(i)=46.5 microM), metyrapone (K(i)=46 microM) and alpha-naphthoflavone (K(i)=78.8 microM). 5-Sulfoxidation of promazine was inhibited only by quinine (K(i)=28.6 microM), whereas that of perazine-by quinine (K(i)=10 microM) and metyrapone (K(i)=96 microM). The results obtained are compared with our previous findings of analogous experiments concerning thioridazine, and with the data on other phenothiazines and species. In summary, it is proposed that N-demethylation of the mentioned phenothiazine neuroleptics in the rat is catalyzed by the isoenzymes CYP2D1, CYP2B2 and CYP1A2 (CYP1A2 does not refer to promazine). 5-Sulfoxidation of these drugs may be mediated by different isoenzymes, e.g. CYP2D1 (promazine and perazine), CYP2B2 (perazine) and CYP1A2 (thioridazine). Isoenzymes belonging to subfamilies CYP2C and CYP3A do not seem to be involved in the metabolism of the investigated neuroleptics in the rat. The results obtained point to the drug structure and species differences in the contribution of cytochrome P-450 isoenzymes to the metabolism of phenothiazines.

Fructose-1,6-diphosphate attenuates acute lung injury induced by ischemia-reperfusion in rats

OBJECTIVE

To determine whether fructose-1,6-diphosphate (FDP) pretreatment can attenuate acute lung injury induced by ischemia-reperfusion in our isolated lung model in rats.

DESIGN

Randomized, controlled study.

SETTING

Animal care facility procedure room.

SUBJECTS

Twenty-four adult male Sprague-Dawley rats each weighing 250-350 g.

INTERVENTIONS

Typical acute lung injury in rats was induced successfully by 10 mins of hypoxia followed by 75 mins of ischemia and 50 mins of reperfusion. Ischemia-reperfusion significantly increased microvascular permeability as measured by the capillary filtration coefficient, lung weight gain, lung weight to body weight ratio, pulmonary arterial pressure, and protein concentration of bronchoalveolar lav-age fluid.

MEASUREMENTS AND MAIN RESULTS

Pretreatment with FDP significantly attenuated the acute lung injury induced by ischemia-reperfusion as shown by a significant decrease in all of the assessed variables (p <.05 p <.001). The protective effect of FDP was nearly undetectable when promazine (an ecto-adenosine 5-triphosphatase inhibitor) was added before FDP pretreatment.

CONCLUSIONS

Pretreatment with FDP significantly ameliorates acute lung injury induced by ischemia-reperfusion in rats.

Effects of general anesthesia and surgery on renal function in healthy dogs

OBJECTIVES

To evaluate renal function in healthy dogs undergoing general anesthesia and ovariohysterectomy without concurrent IV administration of fluids.

ANIMALS

35 healthy client-owned dogs.

PROCEDURE

Dogs were medicated with promazine hydrochloride (0.05 mg/kg of body weight, SC) approximately 45 minutes before induction of anesthesia with thiopental sodium (10 to 15 mg/kg, IV). Anesthesia was maintained with 2% halothane in oxygen. Ovariohysterectomies were performed by senior veterinary students under the direct supervision of a veterinary surgeon. Renal function was assessed (serum urea and creatinine concentrations, fractional clearance of sodium, urine alkaline phosphatase [ALP] and gamma-glutamyltransferase [GGT] activities, urine specific gravity, and enumeration of renal tubular epithelial cells in urine sediment) prior to and 24 and 48 hours after surgery.

RESULTS

Duration of general anesthesia ranged from 80 to 310 minutes. Urine specific gravity and ALP activity and serum urea and creatinine concentrations did not change over time. Fractional clearance of sodium decreased 24 and 48 hours after surgery, whereas urine GGT activity and the ratio of urine GGT activity to urine creatinine concentration increased 24 hours after surgery, compared with presurgery values. Renal tubular epithelial cells increased in number in urine sediment from 11 of 35 (31.4%) dogs and 5 of 35 (14.3%) dogs 24 and 48 hours after surgery, respectively. However, this increase was not clinically relevant.

CONCLUSIONS AND CLINICAL RELEVANCE

Intravenous administration of fluids to healthy dogs undergoing general anesthesia and elective surgery may not be necessary for maintenance of renal homeostasis.

Effects of caffeine and promazine hydrochloride on plasma catecholamines in thoroughbreds at rest and during treadmill exercise

Our aim was to investigate plasma catecholamine responses to so-called 'doping' drugs and exercise in Thoroughbreds. Plasma adrenaline (Ad) and noradrenaline (NA) were determined after the administration of caffeine and promazine hydrochloride (PRZ) using a high performance liquid chromatographic method. Caffeine or PRZ was administered i.m. to Thoroughbreds and its effects on plasma catecholamines at rest and during exercise were compared with the saline control. The treadmill exercise was performed 1 h after administration. A dose of 5.0 mg/kg bwt caffeine was found to significantly increase both plasma Ad and NA levels but this was not the case for the 2.5 mg/kg bwt dose and their peak levels at 1.5 h were about 3 and 2.5 times as compared with the control values at 1.5 h (Ad: mean +/- s.e. 21.2 +/- 2.8 pg/ml, NA: 55.5 +/- 4.1 pg/ml), respectively. Both 1.0 and 1.5 mg/kg bwt PRZ doses reduced the plasma Ad to below the detection limit (10 pg/ml) and significantly reduced the plasma NA. The 2.5 mg/kg bwt caffeine dose significantly increased plasma Ad and NA during exercise and approximately doubled their maximal values as compared with the saline control (Ad: mean +/- s.e. 12.328 +/- 4.733 ng/ml, NA: 9.997 +/- 4.146 ng/ml). The 1.5 mg/kg bwt PRZ dose decreased the plasma Ad during exercise but the effect was not significant. On the other hand, PRZ significantly increased the plasma NA as compared with the saline control. In conclusion, the present study demonstrates that the plasma catecholamine responses to caffeine and PRZ were modified by exercise. It is probable that the modification may be related to exercise-induced activation of the sympathetico-adrenal axis.

Interactions between promazine and antidepressants at the level of cellular distribution

The pharmacokinetic interactions in clinical combinations of a phenothiazine neuroleptic and antidepressants at the level of cellular distribution were investigated. Uptake experiments were performed on slices of various rat tissues as a system with intact lysosomes. Promazine and antidepressants (imipramine, amitriptyline, sertraline, fluoxetine) were incubated separately or jointly with tissue slices for 1 hr. Initial concentration of each drug was 5 microM. The interaction studies were carried out in the absence and presence of ammonium chloride (20 mM), a lysosomotropic compound which increases the internal pH value of lysosomes. All the tissues known for their abundance of lysosomes (the lungs, liver, kidneys) were the site of an interaction between promazine and antidepressants. The neuroleptic and antidepressants mutually inhibited their tissue uptake. The potency of interference of each antidepressant with the lysosomal uptake of promazine was similar. The interactions did not occur in the presence of ammonium chloride, which indicates involvement of the lysosomal trapping. Carbamazepine, a lipophilic but non-lysosomotropic drug, did not interfere with the promazine uptake, and the adipose tissue containing very few lysosomes was never the site of interaction in our experiment. Distribution interactions were also observed in the brain and in some cases in muscles (the tissues less abundant of lysosomes), the effect of the inhibitory drug being usually more potent than that of ammonium chloride. Most of the interactions occurring in these two tissues were also observed in the presence of ammonium chloride. Most of the interactions occurring in these two tissues were also observed in the presence of ammonium chloride, which suggests involvement, at least partially, of a non-lysosomal trapping mechanism. The consequences of the observed distributive interactions at the level of lysosomal trapping in vitro are diminished intralysosomal concentration of the basic lipophilic psychotropic and its increase in cell membranes and fluids. In vivo, a shift from the organs or tissues rich in lysosomes to those less abundant in these organella, and an increase in the free drug concentration in body fluids may be expected. In conclusion, the obtained results show that, regardless of the previously known metabolic interactions between psychotropics, interactions at the levels of cellular and body distribution are also feasible.

[The effect of neuroleptics on blood proteins during development of toxic cerebral edema-brain swelling]

Simulation of toxic brain edema-swelling allowed one to analyze the dynamics of blood protein alteration in presence of various neuroleptics. Alterations in blood protein fractions correlated with dynamics of nervous tissue impairments. All the drugs studied exhibited similar antiswelling action involving the gamma-globulin sub-system activation. At the same time, the neuroleptics with activating and depriving effects demonstrated an oppositely directed influence on blood albumins.

The duration of the movement aftereffect as an index of psychiatric illness

The duration of the movement aftereffect (MAE) has sometimes been used to make inferences about the subject's state (for example, their level of arousal). Some studies are reviewed in which visual aftereffects (including the MAE) were measured in schizophrenia, with inconsistent results. Some relevant psychopharmacological and neurological evidence is considered. It is concluded that: (i) Differences in the clinical status of the schizophrenic subjects and whether they were receiving medication, but not the method used to measure aftereffects, may underlie the interstudy disagreements. (ii) The effect of schizophrenia is to increase MAE duration, and this is not due to some peripheral artefact. (iii) Longer MAEs in the illness could result from enhanced neurally signalled contrast and/or from the increased adaptability of cortical neurons.

[The effect of combolen on the erythrocyte distribution in the dog]

The effect of Combolen (3.9 mg/kg bw s.c.) on the distribution of erythrocytes in dogs was investigated. After application of Combolen, the hematocrit of the animals decreased exponentially within 1 h by 21%. The reversal of the reduction began from 2 h after the time of application, amounting to 4% within the first day and finishing by the fourth day. After injection of 51Cr-labelled erythrocytes, radioactivity in the circulation of Combolen-treated dogs decreased exponentially within 2 h by at least 30%. It was concluded that the dog's spleen, under physiological conditions, contains about 10% of the animal's blood. The time-courses of the decrease of hematocrit and radioactivity in the circulation were found to be very similar. In accordance with this observation, a high correlation (r = 0.97) between the level of radioactivity after injection of radio-labelled erythrocytes and the corresponding hematocrit values after application of Combolen was found. After application of erythrocytes, labelled with 99mTc, an extensive distribution from the circulation into the spleen was observed by scintigraphy. This process can be understood by using a closed-compartment model. An equation, based on this model, describes the observed time course of the hematocrit values, as well as the number of 51Cr-labelled erythrocytes, in Combolen-treated dog. Presumably, the observed effect of Combolen is the result of the relaxation of the smooth muscle cells in the trabeculae of the spleen, caused by central-nervous depression of sympathetic tone. Combolen seems to be a suitable tool in pre-clinical testing of a novel blood preserve with dog as a test animal. Its potent ability to eliminate erythrocytes from circulation is distinguishable from the sequestration of damaged red cells. Furthermore, its ability to prevent the spleen from uncontrolled hematocrit modulating actions in addition to its sedative effects is considered to be an invaluable advantage.

Inhibition and induction of cytochrome P450 2B1 in rat liver by promazine and chlorpromazine

Phenothiazine tranquilizers have been associated with pharmacokinetic drug interactions in man. In this study the in vivo and in vitro effects of the clinically important phenothiazines promazine (PZ) and chlorpromazine (CPZ) on drug oxidations catalysed by specific cytochrome P450 (P450) enzymes were investigated in the rat. In vitro, the two drugs were relatively ineffective inhibitors of constitutive P450 activities, but were inhibitory toward the principal phenobarbital-inducible P450 2B1 and, to a lesser extent, P450 1A1. Administration of PZ and CPZ to male rats did not markedly influence the total microsomal P450 content of the liver. However, the quantitatively important male-specific P450 2C11 was down-regulated by CPZ and concomitant induction of P450 2B1 and associated 7-pentylresorufin O-depentylase activity were noted. A small increase in the activity of microsomal 7-ethylresorufin O-deethylase was also observed following administration of both drugs to rats, suggesting induction of P450 1A1/2. Considered together, it is apparent that the two phenothiazines are preferential inhibitors and inducers of P450 2B1 in rat liver. Drug interactions in humans involving phenothiazines may reflect a combined effect of induction and inhibition processes as well as down-regulation of other P450s, such as that produced by CPZ on P450 2C11.

[Effect of phenothiazine derivative on adrenal cortex response of sheep to repeated emotional stress]

The study was aimed at the evaluation of propiopromazine (Combelen, Bayer), a derivative of phenothiazine, as an agent lowering in sheep the response to stress. The stress of emotional origin was induced in sheep by the isolation from herd lasting 1 hour. The isolation experiments were repeated 6 times on the same group of sheep, first three isolations (1-3) in daily intervals and next three (4-6) in weekly intervals. Propiopromazine was administered before each isolation experiment. The reaction of sheep to the isolation stress was weaker after propiopromazine administration. This was suggested by smaller increase in blood serum cortisol and glucose levels when compared to sheep subjected to isolation but not receiving the drug. Such effect was especially conspicuous during the course of the first isolation experiment; during the next experiments the difference concerning the reaction to stress between the sheep isolated from the herd receiving and not receiving the drug was gradually diminishing. It was shown in addition that propiopromazine administration to the sheep not subjected to stress caused an increase in cortisol level by 125 per cent and that in glucose level by 35 per cent. These results suggest that propiopromazine administration protects the organism against the effects of emotional stress only partially. Moreover, the effect of its administration gradually weakens with repeating of the stress inducing experiment, and propiopromazine itself may act as a stress inducing factor. It seems therefore that the use of propiopromazine and similar compounds as anti-stress agents may be questionable.

The anti-proliferative properties of 4-benzylphenoxy ethanamine derivatives are mediated by the anti-estrogen binding site (ABS), whereas the anti-estrogenic effects of trifluopromazine are not

We compared the anti-proliferative properties of 4-benzylphenoxy-N ethyl morpholine (morpho-BPE) and trifluopromazine (TFP) on both the human breast cancer cell lines, MCF7, and its tamoxifen-resistant variant RTx6. We found that the calmodulin antagonist trifluopromazine (TFP) which bound ABS weakly, inhibited MCF7 cell growth but did not follow the relationship observed for diphenylmethane derivatives between MCF7-inhibitory potencies and their Ki. Regarding the tamoxifen-resistant RTx6 cells, TFP but not morpho-BPE induced inhibition of the proliferation. Using a tritiated derivative of morpho-BPE, two distinct binding sites could be demonstrated. Indeed, a low affinity binding site was present in both cell lines whereas a high affinity binding site was mainly found in MCF7 cells although being in lower concentration (less than 10%) in RTx6 cells. Both tamoxifen and TFP displaced morpho-BPE from the two binding sites. The uptake and efflux of the tritiated drug were similar in the two cell lines. The drug did not appear to be metabolized. We concluded that TFP and morpho-BPE belong to distinct classes of molecules and that ABS mediates the anti-proliferative action of diphenylmethane derivatives but not the inhibitory effect of the calmodulin antagonist TFP.

Differential effects of psychotropic drugs on feeding in rats: is histamine blockade involved?

The present animal studies tested the hypothesis that drug-induced blockade of histamine-1 receptors leads to appetite stimulation. Test agents included the antipsychotic promazine which has very potent antihistaminic effects, as well as the antipsychotic haloperidol and the antidepressant desipramine which both have negligible antihistaminic effects. In support of the hypothesis, significant appetite stimulation occurred only with promazine, while the other two test agents did not increase feeding, and even produced some suppression in food intake.

Haemodynamic changes during sedation in ponies

The cardiovascular changes induced by several sedatives were investigated in five ponies with a subcutaneously transposed carotid artery by means of cardiac output determinations (thermodilution technique), systemic and pulmonary artery pressure measurements (direct intravascular method) and arterial blood analysis (blood gases and packed cell volume). The cardiovascular depression (decrease in systemic blood pressure and cardiac output) was long lasting (greater than 90 min) after administration of propionylpromazine (0.08 mg/kg intravenous (i.v.)) together with promethazine (0.08 mg/kg i.v.). The phenothiazine-induced sedation was not optimal. alpha 2-Agonists (xylazine (0.60 mg/kg i.v.) and detomidine (20 micrograms/kg i.v.)) induced initial but transient cardiovascular effects with an increase in systemic blood pressure and a decrease in cardiac output for about 15 min. Second degree atrioventricular blocks and bradycardia were seen during this period. The cardiovascular depression was more pronounced during detomidine sedation. Atropine (0.01 mg/kg i.v.) induced a tachycardia with a decrease in stroke volume but did not alter the cardiac output or other cardiovascular parameters. It prevented the occurrence of the bradycardia and heart blocks normally induced by xylazine or detomidine. Atropine potentiated the initial hypertension induced by the alpha 2-agonistic sedatives (especially detomidine). The decrease in cardiac output induced by xylazine, and to a lesser extent by detomidine, was partially counteracted when atropine was given in advance. The atropine-xylazine combination seemed the best premedication protocol before general anaesthesia as it only resulted in minor and transient cardiovascular changes.

[Provoking effect of promazine on EEG in childhood]

The authors report on the sleep activation of the EEG-recordings by Promazine a Phenothiazine derivative that can be used also in babies and in those elder children who does not tolerate sleep deprivation. The EEG-s are much less altered then by other related compounds or by Barbiturates. The greatest efficacy could be reached in generalized epilepsies, but the method was helpful in other epilepsy forms too. It is emphasized that in no case of acute neurological symptoms of not epileptic origin showed the Promazine induced sleep a convulsive activity.

Clinical effects of azaperone-metomidate, as compared to propionylpromazine-xylazine-metomidate or xylazine-ketamine combinations in anaesthesia of dogs

Eighteen dogs of Tanzanian breeds divided into three groups of 6 were anaesthetized using either azaperone-metomidate (2 mg/kg, i.m. and 10 mg/kg i.p., respectively), propionyl promazine-xylazine-metomidate (2 mg/kg i.m., 1 mg/kg i.m. and 10 mg/kg i.p., respectively), or xylazine-ketamine (1 mg/kg i.m. and 11 mg/kg i.m., respectively). The clinical effects on respiration rate, heart rate and body temperature were studied until recovery. Hypersensitivity to noise was associated with azaperone metomidate anaesthesia. The other combination produced a smooth and uneventful induction and recovery from anaesthesia. Muscle relaxation and analgesia were adequate in all groups. Duration of xylazine-ketamine anaesthesia was shortest (30 +/- 5 minutes) followed by azaperone metomidate (50 +/- 15 minutes) and the longest duration was with propionyl promazine-xylazine-ketamine (120 minutes). Azaperone and metomidate was associated with marked increases in cardiac and respiration rates and marked hypothermia, which persisted throughout. Minimal changes were observed in the other combinations. Azaperone-metomidate seems to be preferable due to the moderate period of anaesthesia adequate for most operations. However, all the three combinations offer a practical application because of the convenient route of administration.

Two types of bias in psychophysical detection and recognition procedures: nonparametric indices and effects of drugs

In many conditional discrimination procedures, subjects are required to emit one of two responses in the presence of one stimulus and the other response in its absence. The two responses that occur may be formally differentiated, for example by their positions in the experimental space, and functionally differentiated, by the discriminative stimuli that control their occurrence. For example, the stimuli displayed on two response keys, such as color, may be discriminative stimuli for the particular key on which responses are reinforced. The behavior that occurs under these procedures can be analyzed according to signal detection methods for the control by the stimuli, or sensitivity, and the tendency to make one of the two responses, or bias. The present report describes a procedure that allows the independent assessment of position bias and bias towards the stimulus displayed on the response key and presents nonparametric formulae for their computation. Finally, some representative drug effects are shown indicating that certain drugs may selectively affect the two types of bias.

Alkaline labilization of DNA photosensitized by promazine derivatives

Superhelical pBR322 DNA has been photosensitized in the presence of various promazine derivatives. Agarose gel electrophoresis of the photosensitized DNA reveals that true single-strand breaks are induced during irradiation. Alkaline treatment of the photosensitized DNA with a subsequent alkaline agarose gel electrophoresis demonstrates that in addition to true single-strand breaks, these drugs can induce alkali-labile lesions. Although true single-strand breaks are induced randomly into a 5'-[32P]-end labeled pBR322 DNA fragments, the alkaline-labile alterations are located specifically at the level of guanine residues. A strong correlation seems to exist between the visualization of this labilization and the induction of a covalent photoadduct on guanine by the photosensitization mediated by PZ.

Photosensitization of SV 40 DNA mediated by promazine derivatives and 4'-hydroxymethyl-4,5',8-trimethylpsoralen. Inhibition of the in vitro transcription

In vitro transcription by E. coli RNA polymerase was carried out on SV40 DNA photoreacted with various promazine derivatives. Inhibition of the template activity was recorded with increasing irradiation times in the presence of promazine derivatives. Promazine covalent adducts on guanine did not terminate RNA synthesis and seemed to be bypassed by the enzyme. HMT (4'-hydroxymethyl-4,5',8-trimethylpsoralen) photoreaction with DNA was carried out under two conditions: irradiation with lambda greater than 395 nm favouring monoadduction on pyrimidine residues and irradiation at 360 nm inducing a maximum of interstrand diadducts. Both adducts were able to terminate RNA synthesis on the phototreated SV40 DNA and using the O-methyl-nucleotide sequencing procedure, the termination sites were precisely mapped. Monoadducts on the coding strand and cross-links induced termination two bases away from the covalent adduct, but monoadducts on the noncoding strand did not half RNA polymerase.

Termini generated at the site of the DNA breakage mediated by photoexcited promazines

Promazine derivatives are known to be able to photoinduce, in vitro, direct single-strand breaks into DNA (Decuyper et al., Biochem. Pharmac. 33, 4025-4031 (1984]. Using [32P]end labeled DNA fragments, it is demonstrated that this DNA breakage occurs almost regardless of the nucleotide sequence of the DNA. Using 3'-[32P]end or 5'-[32P]end labeled oligonucleotide and enzymatic digestion of the fragments generated, it is demonstrated that the termini generated at the site of the breakage are 5'-phosphate, 3'-phosphate and 3'-termini which are presumed to be 3'-phosphoglycolate. This is consistent with an attack of the sugar moeity of the sugar-phosphate backbone of the DNA by the reactives species generated upon near-u.v. irradiation of promazine derivatives.

In vivo toxicity of phenothiazines to cells of a transplantable tumor

The toxicities of three phenothiazines, promazine, chlorpromazine, and trifluoperazine, towards cells of a mouse fibrosarcoma were quantified by means of an in vitro assay of clonogenic cell survival. For all three drugs cell kill was proportional to the amount of drug injected. Following injection of equimolar (0.2 mM/kg) amounts, cell survival was progressively reduced for a period of at least 48 h. On the basis of cell survival at 48 h after administration the ranking of the drugs for cytotoxicity, in ascending order, was trifluoperazine, chlorpromazine, promazine. A period of acute hypoxia prior to processing of the tumor did not enhance the toxicity of any of the drugs, and no change in the size of the hypoxic fraction of the tumor was seen 24 h after the injection of chlorpromazine. On this basis it was concluded that there was no evidence of enhanced toxicity of drugs for either chronically or acutely hypoxic tumor cells. A reduction in the number of clonogenic tumor cells per gram of tumor was largely the result of a fall in the number of viable cells recovered from the tumor. The plating efficiency of surviving cells remained constant or was only slightly depressed.

Calmodulin antagonists elevate the levels of 32P-labeled polyphosphoinositides in human platelets

The calmodulin antagonists trifluoperazine, chlorpromazine, perphenazine, promazine, tamoxifen and the naphthalene sulfonamide derivatives W7 and W13 increased the level of 32P-incorporation into human platelet PIP and PIP2. Various drugs with poor anti-calmodulin activity were ineffective. The increase in 32P-PIP and 32P-PIP2 required micromolar concentrations of trifluoperazine and was time-dependent, reaching half-maximal within two minutes of the addition of the drug. These results indicate that the calmodulin antagonists perturb polyphosphoinositide metabolism, probably at the level of the PI- and PIP-kinases and/or the PIP2- and PIP-phosphomonoesterases.

Relationship between growth inhibition and mitochondrial function in petite-negative yeasts. II. Effects of central nervous system drugs upon pathogenic and non-pathogenic Candida species

Six nervous system drugs which inhibited vegetative reproduction of S. cerevisiae arrested also mitotic division of C. utilis, C. albicans and C. tropicalis. Chlorpromazine and chlorpheniramine which proved to be the most effective, affected respiration and cytochrome biosynthesis. Electrophoretic bands with MW congruent to 100 K were faint in silver-stained electrophoregrams of proteins from cells grown in the presence of a sub-inhibitory concentration of chlorpromazine.

Termination sites of the in vitro DNA synthesis on single-stranded DNA photosensitized by promazines

Bacteriophage phi X174 and M13 mp9 single-stranded DNA molecules were primed either with restriction fragments or synthetic primers and irradiated with near UV light in the presence of promazine derivatives. These DNAs were used as template for in vitro complementary chain synthesis by Escherichia coli DNA polymerase I large fragment. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis of the synthesis products and localized by comparison with a standard dideoxy sequencing pattern. More than 90% of the chain terminations were mapped exactly one nucleotide before a guanine residue. In addition, photoreaction was shown to occur more predominantly with guanine residues localized in single-stranded parts of the genome. The same guanine residues could also be damaged when the reaction was performed, in the dark, in the presence of the artificially generated promazine cation radicals. Using the BamHI-SmaI adaptor (5'GATCCCCGGG-3'), it was shown that the guanine alteration was a covalent addition of the promazine, or of a cation radical photodegradation product, on the guanine moiety. Kinetics of chlorpromazine photoaddition on single-stranded and double-stranded DNAs were determined.

The photodynamic effect of chlorpromazine, promazine, and hematoporphyrin on lens protein

Calf lens protein was irradiated with near ultraviolet (UV) light in the presence of the drugs chlorpromazine, promazine, and hematoporphyrin. It then was analyzed by SDS-polyacrylamide gel electrophoresis and amino acid analysis. Marked increases in protein photopolymerization (other than S-S bond formation) and histidine destruction were noted in the presence of these drugs. In all cases, these effects were reduced in the presence of a singlet oxygen quencher, thus suggesting that these photodynamic effects are due, at least in part, to a Type II mechanism.

In vitro cross-linking of bovine lens proteins photosensitized by promazines

Promazine derivatives induce cross-linking of bovine lens crystallins in vitro by irradiation with near-ultraviolet (UV) light in the presence of O2, as revealed by electrophoresis after denaturation. With the five derivatives tested (promazine [PZ], chlorpromazine [CPZ], triflupromazine [ TFPZ ], methoxypromazine [ MTPZ ], and acepromazine [ ACPZ ] ), single-hit kinetics are observed. Evidence implicating the cation radicals of the PZ derivatives as the causative agent of this in vitro effect is presented. Hydroxyl radicals do not appear to be involved in the photo-cross-linking reaction. Sodium ascorbate protects against damage induced either by PZ derivatives plus light or by PZ cation radicals in the dark. These findings are discussed with respect to development of cataracts induced by these drugs in vivo.

Effects of chlorpromazine and promazine on the perception of some multi-stable visual figures

Chlorpromazine (CPZ) and promazine were studied for their effects on the reversal rate and dominance of aspect of several multi-stable (ambiguous) visual figures. The normal perception of some versions of the Schröder Staircase and the Man/Woman figure was biased towards one aspect and CPZ increased this bias compared with saline and promazine. There was a tendency for both CPZ and promazine to lower reversal rate. The results are discussed in relation to explanations of perceptual reversal and some implications are suggested for understanding the functional deficits of schizophrenia.

Maternal and fetal cardiovascular indices during fetal hypoxia due to cord compression in chronically cannulated sheep. II. Responses to promazine

Promazine (Sparine) administered to chronically cannulated pregnant ewes caused significant maternal and fetal tachycardia and hypotension, depressed uterine blood flow and fetal Pao2, and increased fetal Paco2. When the drug was given before brief compression of the umbilical cord, uterine flow was more depressed than by compression alone, the fetal pressor response was attenuated, and fetal posthypoxia tachycardia was augmented. We conclude that promazine taken by a mother could have especially deleterious effects on her fetus when the latter's oxygenation is already depressed (e.g., by cord compression), and suggest that the use of promazine during labor be reevaluated.

Comparison of the effects of antipsychotic drugs on the schedule-controlled behavior of squirrel monkeys and pigeons

Lever pressing by squirrel monkeys and key pecking by pigeons were maintained under a multiple 3-min fixed-interval (FI), 30-response fixed-ratio (FR) schedule by the presentation of food. These responses, which differed under the two schedules, but were similar for both species, were used to compare the effects of antipsychotic compounds from different pharmacological classes. Except for differences in potency levels, the effects of intermediate doses of haloperidol and molindone were similar in monkeys and pigeons; these compounds decreased responding under the fixed-interval schedule at doses that did not affect fixed-ratio responding. Similar effects also occurred with chlorpromazine, promazine and thiothixene in pigeons. With monkeys, however, intermediate doses of promazine decreased fixed-ratio responding more than responding maintained under the fixed-interval schedule, while chlorpromazine and thiothixene produced similar effects on responding under both schedules. The effects of novel antipsychotic, clozapine, differed from those of the other agents in both monkeys and pigeons. With both species clozapine increased fixed interval responding at doses that did not affect responding under the fixed-ratio schedule. Doses required to reduce responding at least 50% were approximately 5 to 160 times greater for pigeons than for monkeys for all drugs except clozapine which was equipotent in both species. In monkeys the order of potency was haloperidol greater than molindone = thiothixene greater than chlorpromazine greater than clozapine greater than promazine, whereas in pigeons the order was haloperidol greater than thiothixene greater than clozapine greater than molindone greater than promazine greater than chlorpromazine.

Centrally mediated drug-induced hyperglycemia in mice

In mice, the hyperglycemic response to a stress, such as repeated orbital puncture, evoked a hyperglycemia through activation of the adrenal medulla and consequent release of catecholamines. This hyperglycemia could be blocked by pretreatment of the mice with the ganglionic blocking agent, chlorisondamine. The hyperglycemic response evoked by single doses of serotonin receptor blocking agents, such as cyproheptadine and methysergide, or by dopamine receptor blockings drugs, such as haloperidol or chlorpromazine, could also be blocked by pretreatment with chlorisondamine. Administration of a single dose of the muscarinic agonist, oxotremorine, also resulted in a hyperglycemia that was blocked by chlorisondamine. The results are compatible with the hypothesis that the adrenal medulla is under the control of a central cholinergic pathway with dopaminergic and serotonergic modulating systems.

Increased paroxysmal activity of partial seizures in man by apomorphine

In order to study the role of dopamine (DA) in the regulation of seizure mechanisms in man, a non-emetic dose of apomorphine, a direct stimulant of DA receptors, was administered to eight patients effected by different types of epilepsy. The EEG changes induced by apomorphine administration in comparison to those elicited by promazine or placebo were evaluated in a double blind cross-over study. Similarly to promazine treatment, apomorphine worsened the EEG recordings of some patients. The apomorphine-induced increase in paroxysmal activity was observed in patients affected by partial epilepsy and was not related to the sleep-inducing properties of the drug. This effect is interpreted as being the result of a stimulation of DA autoreceptors, mediating a decrease of dopaminergic activity in the central nervous system. The use of apomorphine as an EEG activating agent is suggested.

Effects of chlorpromazine and promazine on the visual aftereffects of tilt and movement

The effects of chlorpromazine (CPZ) and promazine on the visual aftereffects of tilt and motion were measured. CPZ markedly reduced the strength of both aftereffects, while promazine produced a smaller and not always significant reduction. Control experiments suggested that the effects were produced in the central visual system rather than by several possible peripheral artefacts or by drowsiness. The effects are discussed with reference to the pharmacological activity of the drugs and their influence on the strength of inhibition in the visual cortex, both in normal subjects and in schizophrenic illness.

Comparison and assessment of drugs used to immobilize Alaskan gray wolves (Canis lupus) and wolverines (Gulo gulo) from a helicopter

One hundred and three Alaskan gray wolves and 12 wolverines were immobilized in the Nelchina and upper Susitna River Basins of southcentral Alaska between March 1977 and May 1981. Sixty-five wolves were immobilized with a mixture of phencyclidine HCl and promazine HCl (PP/HCl); 38 wolves were immobilized with etorphine HCl (EHCl) and 12 wolverines were immobilized with EHCl or with a mixture of EHCl and xylazine HCl (XHCl). Phencyclidine HCl is no longer commercially available and an assessment of etorphine HCl as a replacement drug was made. Etorphine HCl dosage of 2.5 mg/wolf proved to be a suitable replacement for PP/HCl for immobilizing wolves while 0.7 mg EHCl with 50 mg XHCl appeared suitable for wolverines.