title: Increased lactate appearance and reduced clearance during hypoxia in dogs.
abstract: In order to assess the effects of severe hypoxia on whole body glucose and lactate kinetics, nine experiments were performed on anesthetized, ventilated mongrel dogs. [U-13C]glucose and [1-14C]lactate (n = 5), or [6-14C]glucose and [U-13C]lactate (n = 4) were infused using the primed-continuous infusion method. Cardiac output was measured by thermodilution. After a control period with 21% O2, inspired O2 was reduced for 90 minutes. Three of the experiments resulted in unstable hemodynamics and lactate levels, and are excluded from the mean data. Arterial PO2 fell from a control level of 106.8 +/- 11.9 to 24.2 +/- 3.5 mmHg during the last 45 minutes of hypoxia, and O2 transport fell to 52% of normoxic values. Arterial lactate concentration and the rate of appearance increased by 428% and 182%, respectively, from control to hypoxia. The metabolic clearance rate for lactate fell by 34%. Arterial glucose levels did not change significantly with hypoxia, but the rate of glucose disappearance rose by 70%, and the rate of glucose conversion to lactate increased 3-fold. It is concluded that acute severe hypoxia in anesthetized dogs causes 1) a large increase in arterial lactate levels, but no significant change in glycemia, 2) a large increase in the rate of lactate disappearance and only a small increase in the rate of glucose disappearance and 3) a fall in the metabolic clearance rate of lactate.
authors: Department of Medicine, University of California, San Francisco.
authors: W C
authors: WC
authors: Stanley
authors: C D
authors: CD
authors: Mazer
authors: R A
authors: RA
authors: Neese
authors: J A
authors: JA
authors: Wisneski
authors: B A
authors: BA
authors: Cason
authors: K A
authors: KA
authors: Demas
authors: R F
authors: RF
authors: Hickey
authors: E W
authors: EW
authors: Gertz
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D004285:Dogs; D005947:Glucose / Q000378:metabolism*; D000860:Hypoxia / Q000209:etiology / Q000378:metabolism*; D007773:Lactates / Q000097:blood / Q000493:pharmacokinetics*; D019344:Lactic Acid; D008657:Metabolic Clearance Rate; D013997:Time Factors
chemical_list: D007773:Lactates; D019344:Lactic Acid; D005947:Glucose