Cerebral blood flow is regulated by all except

Intracranial pressureMean aerial pressure at brain levelThe direct dilator action of CO2 is most pronounced in the skin and brainIf the cerebral blood flow is known, it is possible to calculate the consumption or production by the brain of O2, CO2, glucose- in other words, cerebral blood flow is regulated with the above factors which depend on the cerebral blood flowRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:575