[Hyperalaninaemia during acute hypoxia in the anesthetized rabbit (author's transl)]

Blood alanine (Ala), an important glucose precursor, has been demonstrated to result mainly from the transamination of pyruvate derived from glucose in muscle [10]. A positive relationship between blood pyruvate and blood alanine was reported during muscular exercise and fasting. The alanine/pyruvate relationship in arterial blood has been studied in male fasted anesthetized rabbits before, during and after a short term hypoxic stress (50 minutes). Three groups of animals were studied : normoxic control (FIO2 = 0.28 ; n = 3) (C), hypoxic hypoxia (FIO2 = 0.10 ; n = 4) (HH) and hypoxia induced by respiring the animals with a carbon monoxide containing gas mixture (FIO2 = 0.28, FICO = 0.002 ; n = 6) (HCO). The hypoxic stress was of similar magnitude in HH and HCO groups. During the hypoxic periods an increase of [Ala] was observed along with hyperlactatemia and hyperpyruvatemia. Hyperalaninemia and hyperlactatemia was higher in HH than in HCO groups and hyperglycemia was observed only in HH group (adrenergic stimulation). In normoxic conditions [Ala] correlates positively with pyruvate. This relationship vanishes during the hypoxic and post hypoxic periods. The percentage increase of [Ala] during hypoxia was larger than that of pyruvate. These data, as well as recent reports in the literature, suggest that elevated [Ala] during hypoxia may result from increased muscular production from glycolytic pyruvate and other amino acids and decreased hepatic utilization (gluconeogenesis).