Gamma-decanolactone: Preliminary evaluation as potential antiparkinsonian drug.

Treatment of Parkinson's disease (PD) includes the use of monoamine oxidase-B (MAO-B) inhibitor drugs. In this work we have evaluated the possible gamma-decanolactone (GD) effect in vitro to inhibit the A and B isoforms of human monoamine oxidase (hMAO) enzyme and their citotoxicity in human hepatoma cell line (HepG2). Also, binding studies to A1, A2A A2B and A3 adenosine receptors were performed. A docking study of gamma-decanolactone has been carried out with the molecular targets of MAO-A and MAO-B isoforms. The physicochemical properties and ability to cross physiological barriers, as the blood brain barrier (BBB), was elucidated by computational studies. The in vivo assays, the rota-rod test, body temperature assessment and open field test were performed in reserpinized mice (1.5 mg/kg, i.p.; 18:00 before) to evaluate the effect of gamma-decanolactone (300 mg/kg), alone or associated with Levodopa plus Benserazide (LD + BZ, 100:25 mg/kg, i.p.). Gamma-decanolactone inhibited preferentially the MAO-B in a reversible manner, with an inhibitory concentration of 50% (IC50) 55.95 ± 9.06 µM. It was shown to be a safe drug since only at the highest concentration decreased the viability of HepG2 cells. It also does not bind to adenosine receptors investigated in this study. The molecular docking study show that the gamma-decanolactone ligand adopts a relatively compact conformation in the active site of hMAO-B, while we note an extended conformation of gamma-decanolactone ligand in the hMAO-A isoform. The physicochemical properties obtained, and the theoretical models utilized for the evaluation of ability to cross the BBB, predict a good gamma-decanolactone bioavailability and access to the central nervous system (CNS). In the in vivo studies, gamma-decanolactone partially reversed the ataxia of the reserpinized mice at 01:00 h and 01:30 h post-administration. Concomitant treatment of gamma-decanolactone with LD + BZ, at 01:30 h showed a potentiation of the reversibility of ataxia and facilitated the reversal of hypothermia caused by reserpine for all measured times (P <0.01 vs vehicle), except at 24:00 h, but not reversed the hypokinesia in the open field test. In summary, the results herein obtained and in conjunction with previous studies, suggest that gamma-decanolactone could be a drug with potential utility as antiparkinsonian drug.

Coumarin analogue 3-methyl-7H-furo[3,2-g] chromen-7-one as a possible antiparkinsonian agent / El análogo de cumarina 3-metil-7H-furo[3,2-g]cromen-7-ona, un posible agente antiparkinsoniano

INTRODUCTION: Parkinson's disease is the second most common neurodegenerative disease. Monoamine oxidase B inhibitors are used in the treatment of this disease concomitantly with levodopa or as monotherapy. Several substituted coumarins have shown activity as inhibitors of monoamine oxidase B. OBJECTIVE: To evaluate the possible antiparkinsonian effects of the coumarin analogue FCS005 (3-methyl-7H-furo[3,2-g]chromen-7-one) in mouse models, as well as its inhibitory activity towards monoamine oxidases (MAO) and its antioxidant activity. MATERIALS AND METHODS: FCS005 was synthesized and the reversal of hypokinesia was evaluated in the reserpine and levodopa models. Moreover, in the haloperidol model, its anticataleptic effects were evaluated. Additionally, the monoamine oxidase inhibitory activity and antioxidant activity of FCS005 were evaluated using in vitro and ex vivo studies, respectively. RESULTS: FCS005 (100 mg/kg) caused the reversal of hypokinesia in the reserpine and levodopa models. This furocoumarin also presented anti-cataleptic effects at the same dose. Besides, it showed selective inhibitory activity towards the MAO-B isoform and antioxidant activity. CONCLUSION: These results attribute interesting properties to the compound FCS005. It is important to continue research on this molecule considering that it could be a potential antiparkinsonian agent.

Introducción. El segundo trastorno neurodegenerativo más común es la enfermedad de Parkinson. Los inhibidores de la monoamino oxidasa B se emplean en el tratamiento de esta enfermedad en monoterapia o concomitantemente con levodopa. Varios compuestos cumarínicos han mostrado actividad como inhibidores de la monoamino oxidasa B. Objetivo. Evaluar los posibles efectos antiparkinsonianos del análogo de la cumarina FCS005 (3-methyl-7H-furo[3,2-g]chromen-7-one) en modelos de ratones, la actividad inhibitoria frente a las monoamino oxidasas (MAO) y la actividad antioxidante. Materiales y métodos. Se sintetizó la furanocumarina FCS005 y, en los modelos de reserpina y levodopa, se evaluó si producía reversión de la hipocinesia; en el modelo de haloperidol se evaluaron sus efectos anticatalépticos. Además, se evaluó in vitro la actividad inhibidora de MAO y, ex vivo, la actividad antioxidante del compuesto FCS005. Resultados. El compuesto FCS005 en dosis de 100 mg/kg produjo la remisión de la hipocinesia en los modelos de reserpina y de levodopa. Esta furanocumarina presentó efectos anticatalépticos con la misma dosis. Además, mostró tener actividad inhibitoria selectiva sobre la MAO B, así como efectos antioxidantes. Conclusión. Los resultados evidenciaron propiedades interesantes del compuesto FCS005. Es importante continuar investigando esta molécula porque puede ser un potencial agente antiparkinsoniano.

Coumarin analogue 3-methyl-7H-furo[3,2-g]chromen-7-one as a possible antiparkinsonian agent / El análogo de cumarina 3-metil-7H-furo[3,2-g]cromen-7-ona, un posible agente antiparkinsoniano

Abstract Introduction: Parkinson's disease is the second most common neurodegenerative disease. Monoamine oxidase B inhibitors are used in the treatment of this disease concomitantly with levodopa or as monotherapy. Several substituted coumarins have shown activity as inhibitors of monoamine oxidase B. Objective: To evaluate the possible antiparkinsonian effects of the coumarin analogue FCS005 (3-methyl-7H-furo[3,2-g]chromen-7-one) in mouse models, as well as its inhibitory activity towards monoamine oxidases (MAO) and its antioxidant activity. Materials and methods: FCS005 was synthesized and the reversal of hypokinesia was evaluated in the reserpine and levodopa models. Moreover, in the haloperidol model, its anticataleptic effects were evaluated. Additionally, the monoamine oxidase inhibitory activity and antioxidant activity of FCS005 were evaluated using in vitro and ex vivo studies, respectively. Results: FCS005 (100 mg/kg) caused the reversal of hypokinesia in the reserpine and levodopa models. This furocoumarin also presented anti-cataleptic effects at the same dose. Besides, it showed selective inhibitory activity towards the MAO-B isoform and antioxidant activity. Conclusion: These results attribute interesting properties to the compound FCS005. It is important to continue research on this molecule considering that it could be a potential antiparkinsonian agent.

Resumen Introducción. El segundo trastorno neurodegenerativo más común es la enfermedad de Parkinson. Los inhibidores de la monoamino oxidasa B se emplean en el tratamiento de esta enfermedad en monoterapia o concomitantemente con levodopa. Varios compuestos cumarínicos han mostrado actividad como inhibidores de la monoamino oxidasa B. Objetivo. Evaluar los posibles efectos antiparkinsonianos del análogo de la cumarina FCS005 (3-methyl-7H-furo [3,2-g ] chromen-7-one) en modelos de ratones, la actividad inhibitoria frente a las monoamino oxidasas (MAO) y la actividad antioxidante. Materiales y métodos. Se sintetizó la furanocumarina FCS005 y, en los modelos de reserpina y levodopa, se evaluó si producía reversión de la hipocinesia; en el modelo de haloperidol se evaluaron sus efectos anticatalépticos. Además, se evaluó in vitro la actividad inhibidora de MAO y, ex vivo, la actividad antioxidante del compuesto FCS005. Resultados. El compuesto FCS005 en dosis de 100 mg/kg produjo la remisión de la hipocinesia en los modelos de reserpina y de levodopa. Esta furanocumarina presentó efectos anticatalépticos con la misma dosis. Además, mostró tener actividad inhibitoria selectiva sobre la MAO B, así como efectos antioxidantes. Conclusión. Los resultados evidenciaron propiedades interesantes del compuesto FCS005. Es importante continuar investigando esta molécula porque puede ser un potencial agente antiparkinsoniano.

Identification of active ingredients in Wuzhuyu decoction improving migraine in mice by spectral efficiency association.

Wuzhuyu decoction is a traditional Chinese medicine used for the effective treatment of migraines, termed 'Jueyin headache', in China. However, there have been few investigations to clarify the composition of Wuzhuyu decoction for the treatment of migraines. In the present study, 10 types of Wuzhuyu decoction were analyzed by chromatograms. 5-hydroxytryptamine (5-HT)-depletion mouse models of migraine were prepared by subcutaneous injection of reserpine and placement of autologous blood clots in the cerebral cortex. The levels of 5-HT, noradrenaline (NE), dopamine (DA), nitric oxide (NO) and nitric oxide synthase (NOS) in the brain tissues and sera of the mice were determined. The ingredients and pharmacodynamic indices of the Wuzhuyu decoctions were analyzed using spectral efficiency association by partial least squares regression. The levels of 5-HT, NE and DA in the mouse brain tissues were reduced to 337.785 ± 84.504, 171.173 ± 65.172 and 242.075 ± 158.621 mg/g brain tissue, respectively. The level of NO in the brain tissues increased to 0.425 ± 0.184 µmol/g protein and the activities of NOS in the brain tissues and sera increased to 0.719 ± 0.477 U/mg and 50.688 ± 8.132 U/ml, respectively. Regarding the ingredients of the Wuzhuyu decoction, those with significant regression coefficients were ginsenoside-Rg1, Re, Rb1, rutaevine (Rv), limonin (Li), evodiamine (Ev), rutaecarpine (Ru) and substance X (awaiting identification). Rg1, Re, Rb1, Rv, Li, Ev, Ru and X in the Wuzhuyu decoction were observed to yield the pharmacological effects, whereas Rb1, Rv and Ev were important in index improvement.

Antidepressant-like effect of the hydroethanolic leaf extract of Alchornea cordifolia (Schumach. & Thonn.) Mull. Arg. (Euphorbiaceae) in mice: involvement of monoaminergic system.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaf of Alchornea cordifolia (Euphorbiaceae) is used in traditional African medicine in the treatment of various neurological and psychiatric disorders including depression. Previous studies have shown its potent antidepressant-like effect in the forced swimming test (FST). Hence, this study sought to investigate the involvement of monoaminergic systems in the antidepressant-like effect elicited by hydroethanolic leaf extract of Alchornea cordifolia (HeAC) in the FST. MATERIALS AND METHODS: HeAC (25-400mg/kg, p.o.) was administered 1h before the FST. To investigate the contribution of monoaminergic systems to antidepressant-like effect, receptors antagonists were injected 15min before oral administration of HeAC (200mg/kg) to mice and 1h thereafter, subjected to FST. RESULTS: HeAC (200 and 400mg/kg, p.o.) produced dose dependent and significant (P<0.001) antidepressant-like effect, in the FST, without accompanying changes in spontaneous locomotor activities in the open-field test. The anti-immobility effect of HeAC (200mg/kg) in the FST was prevented by pretreatment of mice with SCH 23390 (0.05mg/kg, s.c., a dopamine D1 receptor antagonist), sulpiride (50mg/kg, i.p., a dopamine D2 receptor antagonist), prazosin (1mg/kg, i.p., an α1-adrenoceptor antagonist), yohimbine (1mg/kg, i.p., an α2-adrenoceptor antagonist), and GR 127993 (5-HT1B receptor antagonist). Similarly, 3 days intraperitoneal injection of p-chlorophenylalanine (pCPA, 150mg/kg, i.p., an inhibitor of serotonin synthesis) prevented the antidepressant-like effect elicited by HeAC. The combination of subeffective doses of imipramine (5mg/kg, p.o.) or fluoxetine (5mg/kg, p.o.), with HeAC (25mg/kg, p.o., subeffective dose) produced a synergistic antidepressant-like effect in the FST. CONCLUSION: The hydroethanolic extract of Alchornea cordifolia possesses antidepressant-like effect mediated through interaction with dopamine (D1 and D2), noradrenergic (α1 and α2 adrenoceptors), and serotonergic (5HT1B receptors) systems. Also, the potentiation of the anti-immobility effect of conventional antidepressants (fluoxetine and imipramine) by Alchornea cordifolia suggest potential therapeutic effect in depression.

Evaluation of antiulcer and antisecretory potential of Linum usitatissimum fixed oil and possible mechanism of action.

The aim of the study was to evaluate the antiulcer activity of Linum usitatissimum fixed oil against aspirin-, indomethacin-, ethanol-, reserpine-, serotonin- and stress-induced gastric ulceration in rats and histamine-induced gastric ulceration in guinea pigs. Attempts were also made to evaluate the in vitro anticholinergic and antihistaminic activity and in vivo antisecretary and antiulcer activity of oil following pylorus ligation in rats. L. usitatissimum fixed oil exhibited significant antiulcer activity against different ulcerogens in experimental animal models. The fixed oil significantly inhibited acetylcholine- and histamine-induced contraction of guinea pig and rat ileums, respectively, suggesting its anticholinergic and antihistaminic activity. The oil also exhibited significant inhibitory effect on gastric secretion/total acidity and aspirin-induced gastric ulceration in pylorus-ligated rats. The lipoxygenase inhibitory, histamine antagonistic and antisecretory (anticholinergic) effects of the oil could probably have contributed towards antiulcer activity. L. usitatissimum fixed oil may be considered to be a drug of natural origin which possesses significant antiulcer activity. The present observation is the first experimental data showing antiulcer activity of L. usitatissimum fixed oil.

[Effects of Sijunzi Decoction on urine's xylose excretion rate and ATP in mucosa of spleen deficiency rats].

OBJECTIVE: To observe the effects of Sijunzi Decoction on D-xylose excretion rate and ATP content in the mucosa membranes of small intestines of rats with spleen deficiency. METHODS: Spleen deficiency model rats were made by reserpine injection. D-xylose excretion rate was measured with p-bromoaniline method, and the ATP content of small intestines mucosa was detected with bioluminescence method. The correlation between D-xylose excretion rate and ATP content of mucosa was also analyzed. RESULTS: Rats' body weight and D-xylose excretion rate decreased after reserpine injection (P < 0.01, vs control group), but increased after treated with Sijunzi Decoction (P < 0.05, vs model group). The ATP content of mucosa showed no significant difference between model group and control group. There was obviously positive correlation between the change of urine's D-xylose excretion rate and mucosa ATP content. CONCLUSION: Sijunzi Decoction has the activity of improving xylose absorption in spleen deficiency rats, but no obvious effect on their mucosa ATP content. The reducing of urine's D-xylose excretion rate in spleen deficiency rats is accompanied with the decrease of mucosa ATP content.

Effect of Hibiscus rosa sinensis on reserpine-induced neurobehavioral and biochemical alterations in rats.

Effect of methanolic extract of Hibiscus rosa sinensis (100-300 mg/kg) was studied on reserpine-induced orofacial dyskinesia and neurochemical alterations. The rats were treated with intraperitoneal reserpine (1 mg/kg, ip) for 3 days every other day. On day 5, vacuous chewing movements and tongue protrusions were counted for 5 min. Reserpine treated rats significantly developed vacuous chewing movements and tongue protrusions however, coadministration of Hibiscus rosa sinensis roots extract (100, 200 and 300 mg/kg, per orally) attenuated the effects. Biochemical analysis of brain revealed that the reserpine treatment significantly increased lipid peroxidation and decreased levels of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GSH), an index of oxidative stress process. Coadministration of extract significantly reduced the lipid peroxidation and reversed the decrease in brain SOD, CAT and GSH levels. The results of the present study suggested that Hibiscus rosa sinensis had a protective role against reserpine-induced orofacial dyskinesia and oxidative stress.

Changes in serum potassium mediate thiazide-induced diabetes.

Thiazides, recommended as first-line antihypertensive therapy, are associated with an increased risk of diabetes. Thiazides also lower serum potassium. To determine whether thiazide-induced diabetes is mediated by changes in potassium, we analyzed data from 3790 nondiabetic participants in the Systolic Hypertension in Elderly Program, a randomized clinical trial of isolated systolic hypertension in individuals aged >or=60 years treated with chlorthalidone or placebo. Incident diabetes was defined by self-report, antidiabetic medication use, fasting glucose >or=126 mg/dL, or random glucose >or=200 mg/dL. The mediating variable was change in serum potassium during year 1. Of the 459 incident cases of diabetes during follow-up, 42% occurred during year 1. In year 1, the unadjusted incidence rates of diabetes per 100 person-years were 6.1 and 3.0 in the chlorthalidone and placebo groups, respectively. In year 1, the adjusted diabetes risk (hazard ratio) with chlorthalidone was 2.07 (95% CI: 1.51 to 2.83; P<0.001). After adjustment for change in serum potassium, the risk was significantly reduced (hazard ratio: 1.54; 95% CI: 1.09 to 2.17; P=0.01); the extent of risk attenuation (41%; 95% CI: 34% to 49%) was consistent with a mediating effect. Each 0.5-mEq/L decrease in serum potassium was independently associated with a 45% higher adjusted diabetes risk (95% CI: 24% to 70%; P<0.001). After year 1, chlorthalidone use was not associated with increased diabetes risk. In conclusion, thiazide-induced diabetes occurs early after initiating treatment and appears to be mediated by changes in serum potassium. Potassium supplementation might prevent thiazide-induced diabetes. This hypothesis can and should be tested in a randomized trial.

A possible mechanism for anxiolytic and antidepressant effects of alpha- and beta-amyrin from Protium heptaphyllum (Aubl.) March.

In the present study, we examined the anxiolytic and antidepressant effects of the mixture of alpha- and beta-amyrin (AMY), pentacyclic triterpenes isolated from the stem bark resin of Protium heptaphyllum. These effects of AMY were demonstrated by the open-field, elevated-plus-maze, rota rod, forced swimming, and pentobarbital-induced sleeping time tests, in mice. In the open-field test, AMY at the doses of 10, 25 and 50 mg/kg, after intraperitoneal or oral administrations, significantly decreased the number of crossings, grooming, and rearing. All these effects were reversed by the pre-treatment with flumazenil (2.5 mg/kg, i.p.), similarly to those observed with diazepam used as a positive standard. In the elevated-plus-maze test, AMY increased the time of permanence and the number of entrances in the open arms. On the contrary, the time of permanence and the number of entrances in the closed arms were decreased. All these effects were also completely reversed by flumazenil, an antagonist of benzodiazepine receptors. In the pentobarbital-induced sleeping time test, AMY at the same doses significantly increased the animals sleeping time duration. In the rota rod test, AMY did not alter motor coordination and, thus, was devoid of effects, as related to controls. Since AMY, at the doses of 10 and 25 mg/kg, showed a sedative effect in the open field test, lower doses (2.5 and 5.0 mg/kg) were used in the forced swimming test, producing a decrease in the immobility time, similarly to that of imipramine, the positive control. The effect of AMI was greater when it was administered 15 min after imipramine (10 mg/kg). However, the antidepressant AMY effects were not altered by the previous administration of paroxetine, a selective blocker of serotonin uptake. In addition, AMY effects in the forced swimming test were totally blocked by reserpine pretreatment, a drug known to induce depletion of biogenic amines. In conclusion, the present work evidenced sedative and anxiolytic effects of AMY that might involve an action on benzodiazepine-type receptors, and also an antidepressant effect where noradrenergic mechanisms will probably play a role.

El papel de la medicina herbal ayurvédica en el descubrimiento de las propiedades neurolepticas de la reserpina: a propósito de la Rauwolfia serpentina y los orígenes de la era antipsicótica / The role of the ayurvedic herbal medicine in the discovering of neuroleptic properties of reserpine: Rauwolfia serpentina and the origins of antipsychotic era

En el presente trabajo se revisa el papel de la planta Rauwolfia serpentina en el origen de la denominada "era psicofarmacológica". Para ello, se ha sumarizado su empleo en la tradicional medicina ayurvédica, fundamentalmente en los trastornos mentales. En el clásico tratado hindú Charaka Samhita ya se hablaba de una forma de psicosis denominada Ounmaad, uno de cuyos remedios terapéuticos era la "planta de raíz de serpiente". La medicina científica se ocupó del estudio, durante la primera mitad del siglo XX, de las actividades farmacológicas de esta planta, destacando las propiedades sedantes e hipotensivas. Finalmente, se analiza el proceso de aislamiento de los alcaloides de la raíz de Rauwolfia, iniciado en la India, y que concluyó con el descubrimiento de la reserpina en los laboratorios suizos de Ciba. Con la reserpina, el arsenal farmacológico para el tratamiento de la esquizofrenia, sustentado únicamente en la clorpromazina, se vio sustancialmente implementado; permitiendo un gran avance en el manejo de los trastornos psiquiátricos (AU)

Different concepts in first-line treatment of essential hypertension. Comparison of a low-dose reserpine-thiazide combination with nitrendipine monotherapy. German Reserpine in Hypertension Study Group.

Low-dose combination therapy has been proposed as a rational first-line approach to hypertension treatment. We compared the efficacy and tolerability of the fixed combination of reserpine (0.1 mg) plus the thiazide clopamid (5 mg) with its single components and the calcium-antagonist nitrendipine (20 mg) in a randomized, double-blind, parallel study of 273 hypertensive patients with diastolic blood pressure (BP) between 100 and 114 mm Hg. The four groups did not differ regarding baseline characteristics (mean age, 58 years; 51% men; mean BP after a 2-week placebo period, 158 to 160/103 to 104 mm Hg). After 6 weeks of treatment with one capsule daily, mean reductions in sitting BP from baseline at 24 hours after dosing in the reserpine-clopamid combination, reserpine, clopamid, and nitrendipine groups were -23.0/-17.1, -14.0/-11.7, -13.6/-11.9, and -11.6/-12.3 mm Hg, respectively (2P < .01). The corresponding normalization rates (diastolic BP < 90 mm Hg) were 55%, 40%, 36%, and 33% (2P = .11). All patients whose BP had not been normalized at this point received two capsules of the respective medication once daily from weeks 7 to 12. At week 12, mean BP reductions were -25.7/-18.1, -14.6/-12.2, -17.7/-13.4, and -14.9/-15.3 mm Hg in the four groups, respectively (2P < .01). The respective normalization rates were 69%, 35%, 39%, and 45% (2P < .0001). Linear regression modeling indicated that reserpine and clopamid combined acted more than additively. As regards tolerability, adverse experiences were observed in 27%, 28%, 29%, and 48% of patients, respectively (2P < .05). The respective rates of premature discontinuation because of adverse effects were 3%, 3%, 7%, and 13% (2P = .06). In conclusion, a low-dose combination of reserpine and clopamid lowered BP significantly more than both the components alone and nitrendipine. Moreover, the combination was tolerated as well as its components and significantly better than nitrendipine. Thus, the use of this low-dose reserpine-thiazide combination appears to be a rational alternative to conventional monotherapy in the first-line treatment of hypertension.

Effect of acute administration of fish oil (omega-3 marine triglyceride) on gastric ulceration and secretion induced by various ulcerogenic and necrotizing agents in rats.

The fish oil commercially known as Marine-25 (omega-3 marine triglyceride) is an eicosapentaenoic acid (EPA)-rich oil. It was investigated for its ability to inhibit gastric secretion and to protect the gastric mucosa against the injuries caused by pyloric ligation, non-steroidal anti-inflammatory drugs (NSAIDs--aspirin and indomethacin), reserpine, hypothermic restraint stress and necrotizing agents [0.6 M HCl 0.2 M NaOH or 80% (v/v) aqueous ethanol]. The results showed that the fish oil, at a dose of 5 or 10 ml/kg body weight, provided significant protection in the various experimental models used. It produced a significant inhibition of gastric mucosal damage induced by pyloric ligation, NSAIDs, reserpine or hypothermic restraint ulcers. Fish oil also exerted a significant inhibitory action on gastric mucosal lesions produced by various necrotizing agents. Our findings show that fish oil rich in eicosapentaenoic acid possesses both antisecretory and antiulcerogenic effects.

[Chronosensitivity to adelphane-esidrex and sinepres and effectiveness of treatment of patients with hypertension]. / Khronochuvstvitel'nost' k adel'fanu-ézidreksu i sinepresu i éffektivnost' lecheniia bol'nykh gipertonicheskoi bolezn'iu.

24-h trends in central and peripheral circulation in response to pharmacological tests were registered in 40 patients with stage II essential hypertension (EH). Rhythmic patterns of hemodynamic parameters (heart rate, systolic pressure, stroke volume, etc.) sensitivity to adelphane-esidrex were found. Hypotensive effect of this drug was maximal in morning hours because of the fall in arterial pressure due to reduced peripheral resistance. Sinepres chronotherapy given to 18 EH patients turned out superior to conventional treatment (1 pill 3 times a day) given to 20 EH patients. When taken into consideration, chronosensitivity to the above drugs may bring about a reduction in daily and course doses and earlier occurrence of a hypotensive effect.

[The action of reserpine in experimental rabies infection]. / Izuchenie deistviia rezerpina pri éksperimental'noi rabicheskoi infektsii.

Experimental studies in laboratory animals showed reserpine in doses of 0.01-0.05 mg/kg body weight to inhibit the development of rabies infection in white mice and rabbits by 40.0-83.4% depending on the dose and mode of administration. The inhibiting properties of reserpine were demonstrated for both fixed and street rabies virus strains. The protective effect of the drug was manifested after parenteral and oral administration to the infected animals. The experimental data suggest that reserpine may be used as an antiviral drug for protective treatment of rabies in the incubation period.

Enhancement of the release reaction not accompanied with enhanced phosphatidylinositol turnover in the reserpinized rabbit blood platelets.

Thrombin-induced platelet release reaction examined with secretion of calcium and N-acetylglucosaminidase was significantly enhanced in the platelets from reserpine-treated rabbits as compared with the control. On the other hand, 32P-incorporation into phosphatidic acid was suppressed in the reserpinized platelets in activated state. Thrombin induced phosphatidylinositol (PI)-breakdown, which was examined by decreases in radioactivity and content of PI, and an increase in diacylglycerol, was not enhanced in the reserpinized platelets as compared with the control. The phosphorylation of the specific protein coupled to thrombin-induced platelet PI-breakdown was not stimulated in the reserpinized platelets as compared with the control. In contrast to PI, PC-degradation by thrombin was significantly stimulated in the reserpinized platelets. Possible existence of pathway(s) other than that associated with an enhancement of PI-turnover is conceivable as a mechanism involved in platelet release reaction.

[Role of noradrenaline in luteinizing hormone secretion]. / Rol'noradrenalina v sekretsii liuteiniziruiushchego gormona.

The role of noradrenaline in the central regulation of hypophysis gonadotropic function was examined. In intact female rats, administration or noradrenaline into the preoptic area of the diencephalon caused an increase in the blood concentration of luteinizing hormone (LH) in the second half of diestrus-2 and in the morning hours of proestrus. In ovariectomized and estradiol treated rats, noradrenaline also favoured an increase in the LH level in the blood and hypophysis, while in ovariectomized rats, administration of noradrenaline did not produce any appreciable changes in the LH content. It is suggested that ovulatory release of LH during proestrus is mediated by noradrenalinergic innervation of the rostral part of the hypothalamus. Also, the effect of noradrenaline on LH secretion is determined by estrogen levels in the peripheral blood.