Cardioprotective effect of anisodamine against ischemia/reperfusion injury through the mitochondrial ATP-sensitive potassium channel.

Previous clinical studies have shown that anisodamine could improve no-reflow phenomenon and prevent reperfusion arrhythmias, but whether this protective effect is related to the antagonism of the M-type cholinergic receptor or other potential mechanisms is uncertain. The aim of the present study was to investigate the role of the mitochondrial ATP-sensitive potassium channel (mitoK ATP ) in cardioprotective effect of anisodamine against ischemia/reperfusion injury. Anisodamine and 5- hydroxydecanoic acid were used to explore the relationship between anisodamine and mitoK ATP . Using a Langendorff isolated heart ischemia/reperfusion injury model, hemodynamic parameters and reperfusion ventricular arrhythmia were evaluated; in addition, changes in myocardial infarct size, cTnI from coronary effluent and myocardial ultrastructure, as well as ATP, MDA and SOD in myocardial tissues, were detected. In the hypoxia/reoxygenation injury model of neonatal rat cardiomyocyte, cTnI release in the culture medium and levels of ATP, MDA and SOD in cardiomyocytes and mitochondrial membrane potential, were analyzed. Overall, anisodamine could significantly improve the hemodynamic indexes of isolated rat heart injured by ischemia/reperfusion, reduce the occurrence of ventricular reperfusion arrhythmia and myocardial infarction area, and improve the ultrastructural damage of myocardium and mitochondria. The in vitro results demonstrated that anisodamine could improve mitochondrial energy metabolism, reduce oxidative stress and stabilize mitochondrial membrane potential. The cardioprotective effects were significantly inhibited by 5-hydroxydecanoic acid. In conclusion, this study suggests that the opening of mitoK ATP could play an important role in the protective effect of anisodamine against myocardial ischemia/reperfusion injury.

Solasodine glycosides. In vitro preferential cytotoxicity for human cancer cells.

Solamargine [(22R,25R)-spiro-5-en-3 beta-yl-alpha-L-rhamnopyranosyl- (1----2glu)-O-alpha-L-rhamnopyranozyl (1----4glu)-beta-D-glucopyranoze], a glycoside of solasodine preferentially inhibits the uptake of tritiated thymidine by cancer cells. In contrast, solamargine at equivalent concentration, and the mono- and diglycosides of solasodine have a limited effect on the uptake of tritiated thymidine for other cell types, including unstimulated lymphocytes and lymphocytes stimulated with Con A. In contrast the solasodine glycosides do not inhibit the uptake of tritiated thymidine by lymphocytes stimulated with PHA or PWM. The inhibition of tritiated thymidine uptake by solamargine and the mono- and di-glycosides of solasodine are dependent upon their cellular uptake by endogenous endocytic lectins (EELs). The mode of action of the solasodine glycosides, in particular solamargine, appears to be the induction of cell lysis, as determined by morphological examination.

[Sites of seizure discharges after intracerebroventricular injection of anisodamine and the antagonism by diazepam in rabbits].

Anisodamine is a tropine alkaloid isolated from Scopolia tangutica Maxim. To determine the original sites of anisodamine seizure discharge, permanent electrodes were implanted into different parts of the brain in rabbits and the electrical activities were continuously recorded by monopolar leads. Injection of anisodamine 1.5 mg/kg into the lateral ventricle of conscious rabbits always produced abnormal discharges. The spike discharges appeared first in the amygdala and consisted of rhythmic large surface-positive spikes. Multiple spikes then appeared in the hippocampus, caudate nucleus, midbrain reticular formation and frontal cortex. Diazepam 1.5-2.5 mg/kg did not inhibit the spike discharges from the amygdala, but did inhibit the discharges from other sites as well as clonic convulsions. When the dosage of diazepam was increased to 4.5 mg/kg, the spike discharges from the amygdala were also inhibited. The above findings indicate that the site of origin of anisodamine seizure discharges in rabbits is the amygdala. The seizure discharges then spread to the mesencephalic reticular formation, the hippocampus, the caudate nucleus and the cortex. Diazepam was shown to be an effective antagonist against central stimulation induced by anisodamine.

Learning deficits induced by 4 belladonna alkaloids are preferentially attenuated by tacrine.

AIM: To examine the antagonism of tacrine on the amnesic effects of scopolamine (Sco), anisodine (AT3), atropine (Atr), and anisodamine (Ani). METHODS: Cognitive functions and locomotor activities were determined using two sessions of step-through and open-field tests, respectively. Mice were injected with one of the belladonna alkaloids (0.05-50 mumol.kg-1, i.p.) and tacrine (50 mumol.kg-1, s.c.) 30 min before the first session. RESULTS: Tacrine completely blocked the avoidance-learning deficit caused by Sco 0.5 mumol.kg-1, AT3 and Atr 5 mumol.kg-1, or Ani 50 mumol.kg-1. But tacrine partly antagonized the learning deficit induced by Sco 5-50 mumol.kg-1 or Atr and AT3 50 mumol.kg-1. The avoidance-memory deficit caused by Sco 0.05-5 mumol.kg-1 or Atr 5 mumol.kg-1 was completely or partly attenuated by tacrine, which did not antagonize the memory deficit elicited by Sco and Atr 50 mumol.kg-1, AT3 5 and 50 mumol.kg-1, and Ani 50 mumol.kg-1. During the acquisition, the locomotor activity of the mice was inhibited by tacrine. This reduction was completely antagonized by Sco 0.5-50 mumol.kg-1, AT3 5-50 mumol.kg-1, Atr 5-50 mumol.kg-1, and only partly antagonized by AT3 and Atr 0.5 mumol.kg-1 or Ani 50 mumol.kg-1. CONCLUSION: Compared with the avoidance-memory deficit, the avoidance-learning deficit caused by belladonna alkaloids is more preferentially attenuated by tacrine.