Biomaterial Database

Cerebral blood flow and oxygen consumption in the rat in hypoxic hypoxia. 1975

H Jóhannsson, and B K Siesjö

In order to measure cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRo(2)) at pronounced degrees of hypoxic hypoxia the Pao(2) of artificially ventilated and normocapnic rats was reduced to between 47 and 22 mm Hg for 15-25 min with subsequent measurements of CBF, using a -133Xenon modification of the Kety and Schmidt technique, and of the arteriovenous difference in oxygen content, the venous blood being obtained from the superior sagittal sinus. When the Pao(2) was reduced to minimal values of 22 mm Hg CBF increased 4- to 6-fold, the increase in CBF being unrelated to changes in blood pressure or Paco(2). The CMRo(2) remained unchanged at all levels of hypoxia. It is concluded that the maintenance of a normal, or near-normal, cerebral energy state even at extreme degrees of hypoxic hypoxia depends solely on a homeostatic increase in CBF.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010313	Partial Pressure	The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Partial Pressures,Pressure, Partial,Pressures, Partial
D001769	Blood	The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D002560	Cerebrovascular Circulation	The circulation of blood through the BLOOD VESSELS of the BRAIN.	Brain Blood Flow,Regional Cerebral Blood Flow,Cerebral Blood Flow,Cerebral Circulation,Cerebral Perfusion Pressure,Circulation, Cerebrovascular,Blood Flow, Brain,Blood Flow, Cerebral,Brain Blood Flows,Cerebral Blood Flows,Cerebral Circulations,Cerebral Perfusion Pressures,Circulation, Cerebral,Flow, Brain Blood,Flow, Cerebral Blood,Perfusion Pressure, Cerebral,Pressure, Cerebral Perfusion
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia