CENTRAL IMIDAZOLINE RECEPTORS AS A TARGET FOR CENTRALLY ACTING ANTIHYPERTENSIVE DRUGS

Imidazoline (I-1)-receptors in the central nervous system play a role in the central regulation of blood pressure and heart rate. Stimulatio n of these receptors in the rostral ventrolateral medulla induces peri pheral sympathoinhibition, and hence a reduction of elevated blood pre ssure. The imidazoline derivatives moxonidine and rilmenidine are mode rately selective I-1 receptor stimulants which have been introduced as centrally acting antihypertensives. Since they have little affinity f or alpha(2)-adrenoceptors, they may be expected to cause less sedation and dry mouth than the alpha(2)-adrenoceptor agonists clonidine and m ethyldopa. The concept of I-1 receptors and their agonists therefore o ffers the possibility to develop centrally acting antihypertensives wi th a more favourable profile of adverse reactions than the classical a lpha(2)-adrenoceptor stimulants such as clonidine and methyldopa.