Cerebrospinal fluid pressure during cerebroventricular infusion of angiotensin and vasopressin

Rationale exists for suspecting that angiotensin (Ang) and arginine vasopressin (AVP) given by the intracerebroventricular (IVT) route can affect cerebrospinal fluid (CSF) pressure. This hypothesis was tested in conscious, unrestrained adult male Sprague-Dawley rats with IVT and left carotid arterial catheters. The rats were infused (IVT) for 30 min with artificial CSF followed by 30 additional minutes with CSF, Ang, (0.6 micrograms/h) AVP (5 or 50 ng/h), or AVP (5 or 50 ng/h) + Ang, (0.6 micrograms/h). Angiotensin evoked a central hypertensive effect (+ 16 mm Hg) and increased CSF pressure from 10 to 16 cm H2O (P less than 0.05). Neither dose of AVP affected blood or CSF pressures. The AVP (5 ng/h) prevented Ang-induced changes in blood and CSF pressures and AVP (50 ng/h) blocked only the Ang-induced rise in CSF pressure. These results raise the possibility that angiotensin and vasopressin participate in the regulation of CSF pressure.