Kokoro Hino

The Effects of Sacral Acupuncture on Acetic Acid-induced Bladder Irritation in Conscious Rats

OBJECTIVES To investigate the effects of sacral acupuncture on acetic acid-induced bladder irritation using cystometry in conscious rats, with particular focus on effects on afferent fibers of the bladder. METHODS A total of 40 female Sprague-Dawley rats weighing 200-270 g were used. The animals were divided into 5 groups: (1) rats with bladder overactivity induced by acetic acid, without sacral acupuncture stimulation (irritated bladder group); (2) rats treated with sacral acupuncture stimulation after induction of bladder overactivity by acetic acid (acupuncture stimulation group); (3) rats treated with sacral acupuncture stimulation after capsaicin desensitization (capsaicin-desensitized group); (4) rats treated with atropine (atropine injection group); and (5) rats treated with sacral acupuncture stimulation after nonacetic acid infusion (nonirritated bladder group). Cystometry was carried out without anesthesia, and the following variables were measured in all animals: intercontraction interval (ICI), basal pressure, threshold pressure, and micturition pressure. RESULTS In the acupuncture stimulation group, sacral acupuncture stimulation resulted in a 140.1 +/- 5.9% increase in ICI after acetic acid-induced irritation to an interval similar to baseline (P = .072). A significant difference in the percent of ICI increase was observed between the acupuncture stimulation and irritated bladder groups (P < .01). In the capsaicin-desensitized groups and acupuncture stimulation groups, no significant differences in ICI occurred, before and after acupuncture. CONCLUSIONS Sacral acupuncture could contribute to improve acetic acid-induced bladder irritation through inhibition of capsaicin-sensitive C-fiber activation.

Contributions of ADP and ATP to the increase in skeletal muscle blood flow after manual acupuncture stimulation in rats

Objective To investigate the contributions of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to the increase in skeletal muscle blood flow (MBF) observed following manual acupuncture (MA) stimulation in rats. Methods Male Sprague-Dawley rats were used as experimental animals (300–370 g, n=40). MA was applied to the right tibialis anterior muscle (TA) for 1 min using a stainless steel acupuncture needle. In eight rats, high-performance liquid chromatography with the microdialysis technique was used to measure local extracellular concentrations of ATP, ADP, adenosine monophosphate (AMP), and adenosine in the TA. In the remaining 32 rats, fluorescent microspheres (15 µm in diameter) were used to measure MBF in the TA following pre-treatment with either the P2 receptor antagonist suramin (100 mg/kg intra-arterially) or saline (control) (n=16 each). Rats receiving MA (Suramin+MA and Saline+MA groups, n=8 each) were compared with untreated rats (Suramin and Saline groups, n=8). Results MA significantly increased the local extracellular concentration of ATP, ADP, and adenosine (p<0.05, before MA vs 30 min after MA). In addition, MA significantly increased MBF in rats pre-treated with saline or suramin (p<0.01, Saline vs Saline+MA; p<0.05, Suramin vs Suramin+MA, respectively). However, suramin significantly suppressed this MA-induced increase in MBF (p<0.05, Saline+MA vs Suramin+MA). Conclusions These results suggest that both ATP and ADP partially contribute to the MA-induced increase in MBF via P2 receptors. However, further studies are needed to clarify the contributions of other vasodilators.