Can naloxone inhibit the cardiovascular effect of acupuncture?

Effect of Moxibustion Stimulation of Various Skin Areas on Cortical Cerebral Blood Flow in Anesthetized Rats

The effect of moxibustion stimulation of various skin areas (cheek, forepaw, upper arm, chest, back, lower leg, hindpaw and perineum) on cerebral blood flow (CBF) of the parietal cortex was examined in anesthetized rats after eliminating emotional influences. Moxibustion stimulation was performed by burning a moxa cone of about 4 mg weight placed on the shaved skin. CBF of the parietal cortex was measured using a laser Doppler flowmeter. Stimulation of the cheek, forepaw, upper arm and hindpaw produced significant increases in CBF, but stimulation of the other areas did not produce significant responses. Moxibustion stimulation of the forepaw and hindpaw produced an increase in the mean arterial pressure (MAP), while stimulation of the other areas did not. After spinal transection at the 2nd thoracic level, the MAP response to stimulation of the forepaw was abolished, whereas the CBF response to stimulation of the forepaw remained. The CBF response in spinalized rats was not affected by cutting cervical sympathetic and facial parasympathetic nerves, while it was almost abolished by intravenous administration of muscarinic and nicotinic cholinergic blocking agents. The CBF response was abolished by crushing the brachial plexus ipsilateral to the stimulated side. It is suggested that the increase in CBF, independent of MAP and emotional responses, elicited by moxibustion stimulation is a reflex response whose afferent pathway is composed of somatic afferent nerves, and whose efferent pathway involves intracerebral cholinergic nerves. A contribution of endogenous opioids in the present CBF responses was neglected, because naloxone did not influence the CBF responses.

Effects of electroacupuncture on intraocular pressure and hemodynamic parameters in isoflurane anesthetized dogs

The effects of electroacupuncture (EA) on intraocular pressure (IOP) and hemodynamic parameters were evaluated in isoflurane anesthetized 10 (5 males, 5 females) normal mongrel dogs (8.1-9.8 kg, 6-8 years old). After determination of baseline IOP and hemodynamic parameters (cardiac index, systolic arterial pressure, diastolic arterial pressure, heart rate and systemic vascular resistance index), EA was applied at 3 acupoints (LI-4, LIV-3 and GB-37) for 20 min. After the EA treatment, IOP was significantly decreased in the both eyes (p<0.05). However, there were not significant differences in hemodynamic parameters between those of before and after EA treatment. From these results, the EA treatment at LI-4, LIV-3 and GB-37 would be considered one of the valuable methods for the IOP treatment in dogs.

Attenuation of the catecholamine responses by electroacupuncture on Jen-Chung point during postoperative recovery period in humans

In this study, Jen-Chung (J-C) point was stimulated by electroacupuncture (EA) in 10 patients, and by placebo treatment in 10 controls, immediately after termination of inhalation for 15 min. During the postoperative recovery period, plasma catecholamine (CA) levels were assessed before (0) and 15 and 30 min after treatment. The time from cessation of inhalation to the first eye opening and to extubation did not differ between groups. The plasma catecholamine levels increased by 30% from 0 to 15 min in the control group but decreased by 6% in the EA group. The levels at 30 min were approximately the same as at time 0. The change in catecholamine levels from 0 to 15 min was significantly lower (P < 0.02) in the EA groups than the control group.

Increased survival of ischaemic musculocutaneous flaps in rats after acupuncture

The effects of acupuncture on survival of ischaemic musculocutaneous flaps were investigated in the rat. A dorsal cranially based standard flap (2 X 7 cm) was elevated and sutured back in position. The percentage survival of the flaps was estimated after 6 days. Manual acupuncture, electro-acupuncture but not superficial acupuncture significantly increased the survival of the flaps compared to untreated controls. The highest flap survival (92%) was obtained with repeated post-operative high-intensity electro-acupuncture. It is concluded that acupuncture treatment markedly increases experimental flap survival and may be of clinical importance for treatment of local ischaemia.

Failure of narcotic antagonist to alter electroacupuncture modification of halothane anaesthesia in the dog

Sixteen dogs were used to study the analgesic effects of electroacupuncture. Electroacupuncture lowered halothane MAC significantly (1.21 +/- 0.04 to 1.05 +/- 0.05 per cent, p less than 0.005). Reversibility of this effect by narcotic antagonist was then studied, using naltrexone 5 mg . kg-1 injected intravenously (10 dogs) or 0.5 mg . kg-1 intrathecally (3 dogs). We failed to see any reversal of the effect of electroacupuncture on MAC. Narcotic antagonist reversibility of acupuncture effect is taken currently to imply endorphin mediation. Possible explanation for our result include an electroacupuncture analgesia not mediated by endorphins.