Role of dorsal column in pathway of hypotensive effect of the somatic afferent inputs

Abstract

To investigate the role of the dorsal column (DC) in the inhibitory effect of somatic afferent inputs on the central pressor response. The femoral arterial pressure, mean arterial pressure (MAP), electrocardiogram (ECG) and heart rate (HR) of the male SD rats were recorded when the hypothalamic paraventricular nucleus (PVN) was electrically stimulated with or without destruction of DC. The inhibitory effect of the deep peroneal nerve (DPN) on the pressor response induced by stimulation of PVN was observed 20 min or 5 d after ipsilateral DC destruction. Stimulating DPN inhibited the pressor response elicited by electrical stimulation of PVN with an inhibitory rate of 43.29%. Twenty minutes after destroying the right DC, stimulation of the right or left DPN could inhibit the pressor response with an inhibitory rate of 38.64% and 39.97%, respectively (P>0.05); five days later the inhibitory rates remained as 33.87% and 36.86% respectively (P>0.05). The pain responses of both hindlimbs in the rats with the right DC destroyed showed no significant difference compared with the intact rats. DC is not involved in the inhibitory effect of DPN on the pressor response induced by PVN stimulation.