Dorsal column is not involved in the mechanism of the hypotensive effect by simulating acupuncture on rat hindlimb.

The present study investigated the role of the dorsal column (DC) in the mechanism of the hypotensive effect induced by simulating acupuncture on rat hindlimb. The femoral arterial pressure and electrocardiogram (ECG) of rats were recorded when the hypothalamic paraventricular nucleus (PVN) was electrically stimulated with or without DC lesion. Stimulation of the deep peroneal nerve (DPN) decreased the pressor response elicited by electrical stimulation of the PVN. Thirty minutes after micro-dissection of the right DC, the inhibitory effect of stimulating the right or left DPN on the pressor response induced by stimulation of the contralateral PVN was not altered. Of 6 rats tested, the inhibitory effect of stimulating the right or left DPN could still be observed five days after the right DC was destroyed. The pain responses of both hindlimbs of the rats with the right DC destroyed showed no obvious difference when compared with the sham control rats. These data suggest that the DC is not involved in the inhibitory effect of stimulating the DPN on the pressor response induced by the PVN activation.