RESUMO
<p><b>AIM</b>To investigate the possible role of rate-limiting enzyme of heme metabolism and globin in the development of the low hemoglobin (Hb), red blood (cell) count (RBC) and hematocrit (Hct) after long-term exercise, and effect of nutrition supplement on sports anemia.</p><p><b>METHODS</b>Male Wistar rats were randomly assigned to three groups (n = 10): control (C), exercise (P) and exercise + nutrition (G). Animals in the P and G groups started treadmill running at 30 m/min, 0% grade, 1 min/time. Running time was gradually increased with 2 min/time during initial 5 weeks and final 4 weeks. In addition, running frequency was 2 times/day except initial 2 weeks. At the end of eleventh week, gene expression of 5-aminolevulinate synthase (ALAS), ferrochelatase, alpha-globin and beta-globin in bone marrow were measured with RT-PCR. Mean-while heme oxygenase 1 (HO-1) activity in liver was measured with immunohistochemical method.</p><p><b>RESULTS</b>Eleven weeks of exercise induced a significant increase in HO-1 and a significant increase in gene expression of beta-globin (P < 0.01, P < 0.05, respectively). Treatment with anti-sports anemia compound dosage led to no significant differences in rate-limiting enzyme of heme metabolism and globin in the exercised rats. The G group had a significantly higher HO-1 level in liver than the C group (P < 0.01). These finds showed that exercise was associated with no significant difference in heme synthetase and alpha-globin gene expression, and significant difference in heme catabolic enzyme and beta-globin gene expression.</p><p><b>CONCLUSION</b>The increase of HO-1 activity in liver might be one of the causes of the lower Hb, RBC and Hct status in exercised rats.</p>