[Mechanisms of the increased resistance to blood flow in the spontaneously hypertensive rat].

Limb perfusion in spontaneously hypertensive rats demonstrated increased vascular resistance at maximum vasodilatation which may be related to structural specifics: the development of smooth muscle hypertrophy in resistive vessels and, obviously, decreased total number of functioning arterioles. The obtained "perfusion pressure - noradrenaline dosage" curves provide further evidence to this effect. The shift to the left shown by these curves and their greater steepness in spontaneously hypertensive rats are due to increased vascular reactivity to pressor effects.