Role of Hypothalamic Peptides in the Development of Hypertension

Abstract

Hypertensive animals show remarkable changes in neurotransmitter activities in hypothalamus. The changes appear to have direct effects on the sympathetic nervous system and may have a causal relationship with most forms of hypertension. Although it is generally agreed that catecholamine-containing neurons are concentrated in specific nuclei in hypothalamus and project to preganglionic neurons of spinal sympathetic system, the precise mechanisms by which these neurons are modulated are less settled. Over the past two decades various reports suggest that peptides play major role in the development of hypertension by modulating catecholamine-containing neurons in specific areas of hypothalamus. Since an increased sympathetic activity is the hallmark of both animal and human forms of hyper-tension, a thorough knowledge of peptidergic control of hypothalamic catecholaminergic neurons is crucial. This article will briefly review some of the peptides (particularly neuropeptide Y) which take part in the activation of the sympathetic system through a common central circuitry resulting in the chronic elevation of blood pressure. Attempts will be made to implicate sodium as possible initiating mechanisms for such hypothalamic changes and hypertension.