[Effect of microinjection of adrenaline (E) into the rostral ventrolateral medulla on the parameters of the hemorrheology].

Experiments were performed on SD rats. It was found that hyperviscosity could be induced by restrained conscious rats. Microinjection of adrenaline (E) into the rostral ventrolateral medulla (rVLM) resulted in a facilitatory increase in blood viscosity, which was blocked by bilateral microinjection of alpha-adrenoceptor antagonist (phentola mine) into the same area, but not by beta-adrenocetor antagonist (propranolol). Pretreatment of rVLM area with 6-hydroxydopamine (6-OHDA) or microinjection of phentolamine abolished stress-induced hyperviscosity, while propranolol was without effect. Apparently the E caused increase of the blood viscosity or stress-induced hyperviscosity may be mediated by activation of alpha-adrenoceptor in the rVLM.