Small Doses Of Reserpine Research Articles

Influence of Xingnao Jieyu capsule on hippocampal and frontal lobe neuronal growth in a rat model of post-stroke depression.

The present study established a rat model of post-stroke depression using incomplete ischemia induced by unilateral carotid artery ligation in combination with solitary raising and subcutaneous injection of a small dose of reserpine. After intragastric perfusion with 45 mg/100 g, 15 mg/100 g, and 7.5 mg/100 g of Xingnao Jieyu for 7, 14 and 21 days, neuronal morphology in the frontal lobe and hippocampus was improved, depression state and voluntary behaviors were also effectively improved in rats with post-stroke depression. Moreover, the effects of Xingnao Jieyu at a dose of 45 and 15 mg/100 g were similar to the traditional antidepressant Prozac.

Effect of desipramine on directly or indirectly elicited catecholamine pressor responses in rats.

Abstract Desipramine enhances the pressor effect induced by noradrenaline, adrenaline, dopamine and dimethylphenylpiperazinium in pithed rats, while indirectly acting sympathomimetic amines, such as tyramine and phenethylamine were inhibited. With a similar degree of noradrenaline potentiation, desipramine was more effective than cocaine as an inhibitor of the tyramine pressor response. Desipramine, but not cocaine, was effective in blocking the hypertension induced by small doses of reserpine in animals pretreated with tranylcypromine.

Uptake and storage of catecholamines in rabbit brain after chronic reserpine treatment.

Abstract The brains of rabbits treated chronically with small doses of reserpine have been examined by the histochemical fluorescence method for dopamine, noradrenaline and 5-hydroxytryptamine. Measurements were made 4 and 24 hr after the last reserpine injection both in vivo and in vitro. Evidence has been obtained that the small functionally-important pool of amine can be directly visualized in the fluorescence microscope. It was found to be present intraneuronally, probably localized to amine storage granules. The degree of functional recovery was correlated with the recovery, as shown by the increased fluorescence, of a small intraneuronal pool of amine and with the ability of amine storage granules to take up monoamines.

Morphine Analgesia without Development of Tolerance in Reserpinized Mice

The relationship between the brain monoaminergic mechanism and morphine tolerance was examined in reserpinized mice. In parallel with the reduction of brain monoamine content, the analgesic effect of morphine was reduced in reserpinized animals. At the peak of the reserpine effect, 24 hr after a single dose of 2.5 mg/kg reserpine, i.p., the analgesic effect of morphine was lowered to about 45% of that in naive animals; and 5 days after reserpine treatment, it recovered to about 60% of the control activity. In these animals, the lowered effect of morphine was maintained at the same range during 6 daily repetitions, and the development of tolerance was suppressed. When daily morphine injection was started from 10 days after reserpine treatment, at the time when the brain level of monoamines was still reduced to 60 to 80% of the control, tolerance developed as rapidly as in control animals. On the other hand, daily treatment with a small dose of reserpine, 0.1 mg/kg, neither affected the brain level of norepinephrine and dopamine nor modified morphine analgesia, but completely blocked the development of tolerance. These results may suggest that suppression of the development of tolerance to morphine analgesia is not attributed to the reduction of brain norepinephrine and dopamine by reserpine. Morphine analgesia without development of tolerance in reserpinized mice may indicate the dissociation of the analgesic effect from tolerance liability.

Migraine, tyramine and blood serotonin.

SYNOPSIS Whole blood serotonin levels and headache symptoms were studied in 26 migrainous patients during a three day period with administration of tyramine the first day, reserpine the second day. No significant changes in serotonin occurred after tyramine; headache severity was not associated with change in blood serotonin, which dropped to low levels after a small dose of reserpine without precipitating migraine in most patients.

Reserpine-induced glycogen accumulation in the epithelial cells of the mouse choroid plexus

Adult mice were injected intraperitoneally with a single dose of 3.5 mg/kg or 0.35 mg/kg of reserpine, and the effect of reserpine on glycogen in the choroidal epithelial cells was studied with the light and electron microscopes. A large dose of reserpine induced a prominent transient accumulation of glycogen in the choroidal epithelial cells. In the telencephalic and myelencephalic choroid plexuses, a small amount of glycogen appeared at 3 h after reserpine injection and increased gradually until 12 h. At 24 h, however, the glycogen content was decreased and at 36 h and later glycogen was no longer visible. In the choroid plexus of the third ventricle, the amount of glycogen deposition was slightly smaller, and it first appeared somewhat later and persisted longer. A small dose of reserpine could cause an increase in glycogen content in the choroidal epithelial cells of the telencephalic and myelencephalic plexuses but not in those of the diencephalic plexus. When nialamide, a monoamine oxidase inhibitor, had been given prior to reserpine, the effect of reserpine was abolished. Electron microscopy revealed that in mice treated with reserpine, the stored glycogen in the choroidal epithelial cells appeared in the form of beta-particles and that no appreciable changes were seen in cytological details of the epithelial cells. The effect of reserpine on the choroidal epithelial cells was discussed in relation to a possible mechanism of action of reserpine.

Effects of hemicastration and the subsequent administration of drugs in the mouse.

Summary. Compensatory hypertrophy of the remaining testis was not detected in mice hemicastrated at ages varying from 3 to 18 weeks, and killed 1, 2 or 3 weeks later. The response of hemicastrated mice to drugs and sex steroids was tested to see whether these animals were useful in studying the effects of antigonadotrophic substances. Seminal vesicle weight was significantly reduced by oestradiol, progesterone, methallibure and reserpine (though small doses of reserpine caused unexpected increases). Increase in testis weight was significantly reduced by oestradiol, methallibure, chlorpromazine and reserpine. Correction of seminal vesicle and increase in testis weight for initial body weight was found to be valid and useful. Hemicastrated mice were used to test drugs which inhibit the synthesis of biogenic monoamines: p-chlorophenylalanine reduced seminal vesicle weight but α-methyltyrosine was without effect.

Studies on the experimental gastrointestinal ulcers produced by reserpine and stress. I. Relationship between production of ulcers and changes in tissue monoamines.

The mechanism of ulcer formation by reserpine has been studied by many investigators. Recently, it was demonstrated that even a small dose of reserpine could produce considerably severe ulcers when combined with stress such as restraint (1), conflict (2), electrical stimulation of the hypothalamus (3, 4) and electrical shock through a grid in the floor (4). Concerning the site of action of reserpine, Blackman et al. (5) have described that reserpine-like drugs cause gastric hemorrhage by a mechanism which has an important central component and which involves the liberation of serotonin. On the other hand, Nicoloff et al. (6) reported that norepinephrine administered into the gastric artery provoked ulceration when active acid secretion was present. From these findings it may be considered that ulcers could be produced by peripheral as well as central mechanisms. The author (7) has previously shown that a decrease in serotonin contained in the enterochromaffin cell and norepinephrine contained in vasoconstrictive nerve endings caused by reserpine and stress had close correlation with ulcer formation. In the present paper differences in the ulcerogenic activities between reserpine and its analogues combined with electrical shock through a grid on the floor were investigated. Reserpine analogues used in this study involved two types of drugs, those that release peripheral monoamines and those that release central monoamines.

Cardiovascular effects produced in cats by the chronic administration of small doses of reserpine.

This paper indicates that the chronic administration to cats of small daily doses of reserpine carries with it the danger of alterations in the function of the heart muscle.

The systemic and coronary hemodynamic effects of diazoxide

1. 1. Hemodynamic studies, including the determination of cardiac output and coronary blood flow, have been made before and after the intravenous administration of diazoxide to anesthetized intact dogs and unanesthetized man. The response was essentially the same in the dog and in man. 2. 2. Administration of this agent intravenously was accompanied by an acute reduction in peripheral, total pulmonary, and coronary resistances, with a decrease in systemic and pulmonary arterial pressures and an increase in cardiac output and coronary blood flow. 3. 3. Coronary sinus oxygen content increased, with the per cent increase in coronary blood flow significantly greater than the change in cardiac rate, left ventricular work, and left ventricular oxygen consumption. 4. 4. The acute hemodynamic effects of diazoxide in control animals are not significantly different from the effects in animals pretreated with chlorothiazide or small doses of reserpine. 5. 5. Although both diazoxide and chlorothiazide are benzothiadiazine derivatives, their acute hemodynamic effects differ greatly.

Hypotensive reactions after small doses of reserpine given parenterally.

RESERPINE (Rauwolfia serpentina) has been reported as a useful and effective agent in the treatment of hypertensive crises since 1955. Most authors have recommended the use of 2.5 to 5.0 mg. given ...

A suggested effect on levels of catecholamine in brain produced by small doses of reserpine.

IN a recent communication, Sheppard and Zimmerman1 criticized the results obtained by numerous other workers indicating that reserpine reduces the content of brain norepinephrine and serotonin. Their objections were based on the “toxicological doses” which had been used. However, they failed to mention that reserpine had also been reported to reduce levels of brain serotonin2 and norepinephrine3 in non-toxic doses as low as 0.1 mgm./kgm. and to deplete heart norepinephrine in doses as low as 5 µgm./kgm.4. Sheppard and Zimmerman's results showed that the administration of 0.1 mgm./kgm. of reserpine subcutaneously to female guinea pigs weighing 300 gm. elicited a rise of 74 per cent in brain norepinephrine in 20 min. and a rise in heart norepinephrine of 30 per cent in 20 min. and 45 per cent in 2 hr. No diminution in brain and heart norepinephrine was noted for 8 hr. In contrast, serotonin-levels in the brain fell by 50 per cent in 4 hr. They concluded that their results constituted the first demonstration of a rise in catecholamine content following the administration of reserpine.

A Suggested Effect on Levels of Catecholamina in Brain produced by Small Doses of Reserpine

A Suggested Effect on Levels of Catecholamina in Brain produced by Small Doses of Reserpine