Dynamic pressures in the pial arterial microcirculation.

SHAPIRO, HARVEY M., DON D. STROMBERG, DENNIS R. LEE, AND CURT A. WIEDERHIELM. Dynamic pressures in the pial arterial microcirculation. Am. J. Physiol. 22 l(1) : 279-283. 197 1 .-Using a modified Wiederhielm servo-micropipet system with pipet tips of 0.5-l p diam, we measured and recorded dynamic arterial pressures in 42 arteries and arterioles of the pial vascular network on the surface of the parietal cortex of eight pentobarbitalanesthetized cats. Aortic pressure, mean central venous pressure, and end-tidal CO:! were also recorded. In branches of the middle cerebral artery as large as 455 p od, pressure was only 61 y0 of aortic pressure. Additional pressure-head loss from these major vessels across the pial arterial bed down to the penetrating arterioles (approx. 25 p od) was only 10 %. These results are compatible with the “pressure equalization reservoir” concept of the pial arterial network.