Changes of Functional and Biochemical Blood Parameters in Wistar Rats and in Spontaneously Hypertensive Rats of the SHR Line during Short-Term and Long Tredmill Running
Previous studies of the influence of physical exercise on erythrocyte 2,3-DPG have shown conflicting results, including that exercise induces increase, decrease or no changes in 2,3-DPG. Assuming that the interplay between the factors governing 2,3-DPG metabolism may change considerably during the early phase of recovery after exercise, the level of erythrocyte 2,3-DPG was examined over a prolonged period of time after heavy exercise in five healthy men, on 3 separate days, the duration of exercise being 6 min, 6 min+6 min with 1 h of rest between, and 60 min, respectively. The short exercise periods were accompanied by a substantial lactate acidosis, whereas the 60 min work was essentially aerobic. With the 6 min work, the erythrocyte 2,3-DPG was unchanged or sligthly reduced immediately after and 15 min after the end of exercise, then rose to a new level, 8% above the initial level, 30 min after the exercise (P<0.001). With the 6+6 min work, the pattern of change followed both bouts of exercise, resulting in a two-step increase of 2,3-DPG, to a new level 12% above its initial value (P<0.001). With the 60 min work, 2,3-DPG was increased after 30 min of exercise, and rose continuously during the early recovery phase, to a new level, 10% above initial value, 45 min after the exercise (P<0.001). With all three types of exercise 2,3-DPG remained unchanged during the following 4 h. Thus, heavy exercise is followed by a definite, slowly developing increase in erythrocyte 2,3-DPG, reaching a new level 30–45 min after exercise.