Naloxone reverses inhibitory effect of electroacupuncture on sympathetic cardiovascular reflex responses.

Acupuncture and electroacupuncture (EA) have been used in traditional Chinese medicine to treat a wide range of diseases and conditions, including angina pectoris and myocardial infarction. In a feline model of reflex-induced reversible myocardial ischemia, electrical stimulation of the median nerves to mimic EA (Neiguan acupoint) significantly improved ischemic dysfunction, secondary to an inhibitory effect of EA on reflex pressor effects evoked by bradykinin (BK). The central mechanism of EA's inhibitory effect in this model is unknown. Accordingly, in alpha-chloralose-anesthetized cats, BK (10 micrograms/ml) was applied to the gallbladder to elicit a cardiovascular reflex response that significantly (P < 0.05) increased arterial blood pressure and heart rate; normalized systolic wall thickening (%WTh) of the left ventricle, measured by ultrasonic single-crystal sonomicrometer, increased by 31 +/- 11% (P < 0.05). After ligation of a side branch of the left anterior descending coronary artery, the reflex pressor response to BK resulted in a significant decrease of %WTh (-32 +/- 6%) in the ischemic region. When bilateral EA of the Neiguan acupoints was performed, the pressor response to BK was inhibited and regional myocardial function was significantly improved (+19 +/- 20%). The inhibitory effects of EA on blood pressure and %WTh were reversed by intravenous injection of naloxone (0.4 mg/kg; n = 9) or microinjection of naloxone (10 nM in 0.1 microliter/site; n = 14) into the rostral ventrolateral medulla (rVLM). Thus %WTh with intravenous naloxone was reduced to -13 +/- 29% (P<0.05) during stimulation of the gallbladder. Our results indicate that the inhibitory effect of EA on the BK-induced pressor response and the consequent improvement of ischemic dysfunction is dependent on the activation of opioid receptors, specifically receptors located in the rVLM.

[Inhibitory effect of electroacupuncture on the cardiovascular response evoked by applying bradykinin on the gallbladder].

The effects of electroacupuncture (EA) on the pressor response and reversible myocardial dysfunction induced by application of bradykinin (BK) on the gallbladder were studied in cats anesthetized with alpha-chloralose. The cardiovascular responses evoked by application of BK included a pressor response, an increase of LVP and its dP/dtmax, tachycardia and a decrease of local wall motion of the left ventricle with a supplying branch of the left anterior descending coronary artery ligated beforehand. Following EA of bilateral Neiguan acupionts, the pressor response of BK was inhibited, while the regional left ventricle myocardial dysfunction was alleviated significantly. The effects of EA were reversed by i.v. injection of naloxone (0.4 mg/kg). Our results indicate that EA has an inhibitory effect on the BK-induced pressor and ischemic dysfunction, which may be related with endogenous opioid peptide.

A simple, inexpensive apparatus for performance of preparative scale solution phase multiple parallel synthesis of drug analogs. II. Biological evaluation of a retrospective library of quinolone antiinfective agents.

A series of pure fluoroquinolone antiinfective agents was prepared by multiple parallel synthesis using a simple new apparatus. These compounds were evaluated biologically against Gram-positive and Gram-negative microorganisms and against a BCG strain transfected with luciferase in a fluorescence-based antitubercular assay. Activity against relatively fast growing, acid-fast Mycobacterium smegmatis was determined in part by agar-dilution streak assays. Data obtained against Escherichia coli-derived DNA gyrase does not correlate well with whole cell assays against E. coli. These compounds were assayed by a convenient glass-fiber filter binding method modified for high throughput screening. In these analogs, the results with a N-1 cyclopropyl substituent were often inferior to those obtained with a N-1 2',4'-difluorophenyl substituent. None of the new compounds prepared was superior in its antimycobacterial potency to ciprofloxacin or temafloxacin.

[Effect on electroacupuncture on experimental epilepsy--power spectrum analysis of EEG].

The present study was undertaken to investigate the effect of electroacupuncture (EA) on electroconvulsive shock (ECS) and penicillin-induced convulsions in rats, using power spectrum analysis technique. Under quiet state, delta and theta bands were found to be predominant in the power spectrum of spontaneous EEG's with the peak of the main power in the delta band. During ECS and penicillin-induced convulsions, the power percentage of the delta band decreased, while those of alpha and beta bands increased. The bands with the peak of the main power shifted to the right, and the total power was distinctly enhanced. No marked change in background EEG activity was observed during EA stimulation. In the case of EA plus ECS or penicillin-induced convulsions, the power percentage of the delta band increased, while those of alpha and beta bands decreased. The peak of the main power returned to the delta band with a decreased total power. The compressed power spectrum array showed distinct suppression of convulsions by EA audio-visually. These results suggest that EA enables the EEG to synchronize and enhances the inhibitory process of the brain, thereby plays its anticonvulsant role.