Abstract:
Aiming to investigate the effect mechanism of hypoxia-inducible factor-1α(HIF-1α) on glycolysis capacity of postmortem bovine muscle, the bovine M. Longissimus dorsi was selected as the experimental material, the cellular aggregation and nuclear migration of HIF-1α, expression of HIF-1α and glycogen transporter-1, glycolysis rate-limiting enzymes activities, glycolytic potential, and pH values were determined at different time points of postmortem aging(0 h, 6 h, 12 h, 24 h, and 48 h) in the control group and 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole(YC-1)-treated group. The results showed that HIF-1α was aggregated and translocated to the cell nucleus in bovine muscle at the early stage of postmortem aging. The expression levels of HIF-1α were increased by 1.20-fold at 0~6 h(P<0.05), which were significantly higher than those in the YC-1-treated group at 6~48 h(P<0.05). With the steady accumulation of HIF-1α, the expression levels of GLUT-1 were significantly increased by 1.91-fold within 0~6 h in the control group(P<0.05). The hexokinase(HK) and phosphofructokinase(PFK) activities were significantly elevated to 197.43 U/g protein and 27.33 U/g protein at 0~6 h and 0~12 h, respectively(P<0.05). As for the glycolysis capacity, the glycogen consumption and lactate accumulation rates were significantly higher in the control than those in the YC-1-treated group(P<0.05). The glycolytic potential was significantly increased by 1.10-fold at 0~12 h(P<0.05) and was significantly higher than that of YC-1 treatment from 6 h to 24 h(P<0.05). Meanwhile, pH values in the control group were significantly decreased to the ultimate pH(pHu) at 0~12 h(P<0.05), which was 12 h earlier than that in the YC-1-treated group. The results indicated that HIF-1α played an important role in enhancing the glycolytic capacity of bovine muscle by inducing GLUT-1 expression and elevating the activities of glycolysis rate-limiting enzymes at the early stage of postmortem aging.