Sympathetic influence on sodium-potassium activated adenosine triphosphatase activity of rabbit and rat choroid...

Ouabain-sensitive Na+-K+-ATPase was measured spectrophotometrically in the lateral choroid plexuses of rabbit and rat. In the rabbit, a significant increase in the enzyme activity was seen at one week after unilateral sympathectomy (removal of the superior cervical ganglion), but not at three days or two weeks postoperatively, as compared with the intact, contralateral plexus. Unilateral sympathetic denervation of the rat's choroid plexus induced a nearly 40% decrease in Na+-K+-ATPase activity at 6 days after the operation, while no effect was seen after 12 days. The results agree with a local sympathetic inhibition of CSF production in rabbit (corresponding studies on rat have not been performed), and favor the assumption that the adrenergic nerves in the choroid plexus mediate direct effects on transport functions in the plexus epithelium.