title: Hyperthermia increases cerebral metabolic rate and blood flow in neonatal pigs.
abstract: We examined effects of hyperthermia on cerebral metabolic rate for oxygen (CMRO2) and cerebral blood flow (CBF) in anesthetized, newborn pigs (2-5 days old). CBF and CMRO2 were measured during normothermia (38 degrees C) and during hyperthermia induced by body heating (42 degrees C). During normothermia, total CBF was 32 +/- 3 ml.min-1.100 g-1 (n = 9), and CMRO2 was 1.34 +/- 0.08 ml O2.100 g-1.min-1 (n = 7). During hyperthermia, total CBF increased by 97 +/- 23% and CMRO2 by 65 +/- 24%. We also examined whether cerebral resistance vessels were responsive under these conditions. During hyperthermia, total CBF was 63 +/- 6 ml.min-1.100 g-1, and CMRO2 was 2.13 +/- 0.27 ml O2.100 g-1.min-1. During sustained hyperthermia, intravenous injection of 5 mg/kg of indomethacin decreased total CBF by 45 +/- 7% (n = 9), and CMRO2 fell by 55 +/- 10% (n = 5). We conclude that 1) hyperthermia increases CBF and CMRO2, and 2) the dilated cerebrovascular bed during hyperthermia still is responsive to a constrictor stimulus.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D002245:Carbon Dioxide / Q000097:blood; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D005334:Fever / Q000503:physiopathology*; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009928:Organ Specificity; D010100:Oxygen / Q000097:blood; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects; D013552:Swine
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen; D007213:Indomethacin