Neuromodulation in treatment of hypertension by acupuncture: A neurophysiological prospective

Abstract

Hypertension is a major public health problem affecting over one billion individuals worldwide. This disease is the result of complex interactions between genetic and life-style factors and the central nervous system. Sympathetic hy peractivity has been postulated to be present in most forms of hypertension. Pharmaceutical therapy for hypertension has not been perfected, often requires a multidrug regimen, and is associated with adverse side effects. Acupuncture, a form of somatic afferent nerve stimulation has been used to treat a host of cardiovascular diseases such as hypertension. It has long been established that the two major contributors to systemic hypertension are the intrarenal reninangiotensin system and chronic activation of the sympathetic nervous system. A number of important studies on the baroreflex response and its response to acupuncture are discussed. The inhibitory effects of acupuncture on the rostral ventrolateral medulla (rVLM) reduces sympathetic nerve activity and blood pressure suggesting overactivity of the angiotensin system in this nucleus may play a role in the maintenance of hypertension. Our experimental studies have shown that electroacupuncture stimulation activates neurons in the arcuate nucleus, ventro-lateral gray, and nucleus raphe to inhibit the neural activity in the rVLM in a model of visceral reflex stimulation-induced hypertension. The sig nificant role of spinal cord opioids and no ciceptin are also reviewed. Although clinical studies of acupuncture to date have met some success, they are rarely scientifically robust and do not feature randomization and long-term follow up. Based on a great deal of basic scientific evi dence, large trials are desperately needed to study the effects of acupuncture on the hyper ensive man.