Changes in arterial and cerebral venous blood gases, cerebral blood flow and cerebral oxygen consumption at different stages of thioacetamide-induced hepatogenic encephalopathy in rat.
Rats were subjected to repeated intraperitoneal administrations of thioacetamide (TAA) in order to produce the following stages of hepatogenic encephalopathy (HE): the early stage, characterized by activation of brain metabolism (Group 1), the precomatose stage with impairment of brain metabolism (Group 2) and the stage of recovery (Group 3). A decrease of cerebral blood flow (CBF) of 50%, related to a drop of systemic arterial pressure and to increased hematocrit, were observed in groups 1 and 2 but not in group 3. However, the cerebral oxygen consumption (CMRO2), calculated from arterial venous difference in oxygen content and taking into account CBF, was markedly decreased in group 2, but remained unchanged in group 1. This reflects the state of cerebral metabolism at these stages. The results underscore the necessity of simultaneous monitoring of CBF and blood gases for distinguishing between the particular stages of HE revealed by biochemical tests.
D000641:Ammonia / Q000097:blood; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002245:Carbon Dioxide / Q000097:blood; D002560:Cerebrovascular Circulation; D005260:Female; D006501:Hepatic Encephalopathy / Q000097:blood / Q000139:chemically induced / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains; D013853:Thioacetamide
D013853:Thioacetamide; D002245:Carbon Dioxide; D000641:Ammonia; D010100:Oxygen