A mathematical model of cerebral blood flow chemical regulation. II. Reactivity of cerebral vascular bed

摘要

For pt.I see ibid., vol.36, no.2, p.183-91 (1989). A mathematical model of the chemical oxygen-dependent cerebral blood flow (CBF) regulation in the rat is proposed. The model assumes that oxygen acts on cerebral vessels through an indirect mechanism, mediated by the release of two metabolic substances (adenosine and H/sup +/) from tissue, and that any change in perivascular concentration of these substances affects the diameter of both the medium and small pial arteries as well as that of intracerebral arteriole. The model is composed of several submodels, each closely related to a different physiological event. Mathematical equations which describe the reaction of the vasoactive portion of the cerebral vascular bed are given. The model permits the simulation of the role played by chemical factors in the control of CBF under many different physiological and pathological conditions. Several events associated with an alteration in oxygen supply to tissue have been simulated. The results suggest that chemical factors, adenosine and H/sup +/ play a significant but not exclusive role in the regulation of the cerebral vascular bed. The action of other mechanisms must be hypothesized to explain completely the CBF changes occurring in vivo.