Glutathione and 2,3-diphosphoglycerate in the blood of hypoxic ruminants

Two merino sheep and two angora goats were subjected to simulated altitudes of up to S500 m for about 10 h per day for 38 days. Packed cell volume (PCV), haemoglobin (Hb) concentration and red blood cell (RBC) levels of reduced glutathione (GSH) and 2,3-diphosphoglycerate (2,3-DPG) were measured at regular intervals. Mean PCV increased from 33 per cent to 60 per cent in the sheep and from 33 per cent to 45 per cent in the goats. Mean Hb concentration rose from 11·7 g/dl to 23·1 g/dl in the sheep, and from 11·4 g/dl to 16·0 g/dl in the goats. The level of GSH began to rise in the sheep only after the animals were no longer being subjected to the hypoxic stress, increasing by about 20 mg/dl RBC. In the goats, the levels of GSH rose during, as well as after, the period of hypoxic stress, also by about 20 mg/dl RBC. No change in 2,3-DPG levels was found in either species.