Contributions of nitric oxide and prostaglandins to the local increase in muscle blood flow following manual acupuncture in rats

• Published in: Acupuncture in medicine : journal of the British Medical Acupuncture Society 2015-02, Vol.33 (1), p.65-71
• Main Authors: Shinbara, Hisashi, Okubo, Masamichi, Kimura, Keisaku, Mizunuma, Kunio, Sumiya, Eiji
• Format: Article
• Language: English
• Subjects: Acupuncture Points; Acupuncture Therapy; Animals; Enzyme Inhibitors - pharmacology; Indomethacin - pharmacology; Muscle, Skeletal - blood supply; Muscle, Skeletal - metabolism; Needles; NG-Nitroarginine Methyl Ester - pharmacology; Nitric Oxide - metabolism; Prostaglandins - metabolism; Rats, Sprague-Dawley; Regional Blood Flow
• ISSN: 0964-5284; 1759-9873
• DOI: 10.1136/acupmed-2014-010634

Objective To investigate the contributions of nitric oxide (NO) and prostaglandins (PGs) to the increase in local muscle blood flow (MBF) observed following manual acupuncture (MA). Methods Male Sprague-Dawley rats (n=112; 250–310 g) were injected intraperitoneally with a non-selective NO synthase inhibitor (NG-nitro-L-arginine methyl ester hydrochloride: L-NAME; 10, 50 or 500 mg/kg), a non-selective cyclo-oxygenase inhibitor (indomethacin; 10, 50 or 500 mg/kg), a combination of L-NAME and indomethacin (500 mg/kg each) or saline only under urethane anaesthesia (1.2 g/kg). We used the sparrow pecking technique for 1 min with a stainless steel acupuncture needle (0.20×30 mm) as the acupuncture stimulation method. The stimulus point was on the right tibialis anterior muscle. 51Chromium-labelled microspheres were used for MBF measurement. Results MA increased MBF in the saline-injected group (p0.05, p0.05). Conclusions These results suggest that NO is a major factor in the MA-induced increase in MBF, while PGs do not contribute significantly to this increase. As complete inhibition was not achieved by administration of L-NAME±indomethacin, it appears that non-NO and non-PG vasodilators are additionally involved.