Hypotensive effects of pentobarbital and diuretics on sympathectomized spontaneously hypertensive rats.

The upper abdominal sympathetic chain with the splanchnic nerve was removed bilaterally in spontaneously hypertensive rats(Okamoto-Aoki). After recovery from the operation, the sympathectomized spontaneously hypertensive rats were as hypertensive as intact or sham operated ones. However, anesthesia with pentobarbital or administration of diuretics induced a significantly greater fall of pressure in the sympathectomized hypertensive rats. The hypotensive effect of either drug was insignificant or considerably small, if present at all, in sympathectomized normotensive control rats. It seems that, in intact spontaneously hypertensive rats, the hypotensive effects of pentrobarvital and diuretics are compensated for by a reflex activation of the abdominal sympathetic nerves.