Role of presympathetic C1 neurons in the sympatholytic and hypotensive effects of clonidine in rats

Ann M. Schreihofer and Patrice G. Guyenet . American Journal of Physiology - Regulatory, Integrative and Comparative Physiology Published 1 November 2000Vol. 279no. R1753-R1762. The rostral ventrolateral medulla (rvlm) is important to control of blood pressure (BP) and sympathetic nerve activity (SNA). Clonidine is an antihypertensive medication that acts as an agonist for α1 adrenergic receptor on axons and terminals of rvlm neurons. The purpose of this paper was to determine whether clonidine acted on spinally projecting c1 or no c1 in the rvlm in order to lower SNA and BP. What they found was that after injecting DβH- saporin the response to clonidine. This finding along with previous data from other labs that showed that injections of clonidine into the nucleus tractus solitarius (NTS) and in the intermediolateral cell column (IML) demonstrates that clonidine may act on several areas in the brain in order to have the antihypertensive affect that is known for.-MD