title: Effect of electroacupuncture on pressor reflex during gastric distension.
abstract: The effect of electroacupuncture (EA) on the reflex cardiovascular response induced by mechanical distension of the stomach was studied in ventilated male Sprague-Dawley rats anesthetized by ketamine and alpha-chloralose. Repeated balloon inflation of the stomach to produce 20 mmHg tension on the gastric wall induced a consistent rise in mean arterial pressure, while heart rate (372 +/- 22 beats/min) was unchanged. This response was reversed by transection of the splanchnic nerves. Bilateral application of EA (1-2 mA, 2 Hz) at Neiguan-Jianshi acupoints (pericardial meridian, Pe 5-6) over the median nerve for 30 min significantly decreased the pressor response from 33 +/- 6 to 18 +/- 4 mmHg (n = 7, P < 0.05). This effect began after 10 min of EA and continued for 40 min after termination of EA. EA at Zusanli-Shangquxu acupoints (stomach meridian, St 36-37) over the deep peroneal nerve similarly inhibited the pressor response. The effect lasted for 10 min after EA was stopped (n = 6, P < 0.05), while EA at Guangming-Xuanzhong acupoints (gallbladder meridian, GB 37-39) over the superficial peroneal nerve did not inhibit the pressor response. Naloxone injected intravenously (n = 6) immediately after termination of EA or administered by microinjection into the rostral ventrolateral medulla (rVLM) 25 min after initiation of EA (n = 6) reversed the inhibition by EA, suggesting an opiate mechanism, including the rVLM, was involved.
authors.affiliation: Department of Internal Medicine, College of Medicine, University of California, Irvine, California 92697-4075, USA. pengli@uci.edu
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Kasra
authors.initials: K
authors.lastname: Rowshan
authors.forename: Melissa
authors.initials: M
authors.lastname: Crisostomo
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Tjen-A-Looi
authors.forename: John C
authors.initials: JC
authors.lastname: Longhurst
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D003714:Denervation; D015671:Electroacupuncture; D006339:Heart Rate / Q000502:physiology; D008297:Male; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010543:Peroneal Nerve / Q000502:physiology; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects / Q000502:physiology*; D013153:Splanchnic Nerves / Q000502:physiology; D013270:Stomach / Q000294:innervation* / Q000502:physiology*
chemical_list: D009292:Narcotic Antagonists; D009270:Naloxone