Department of Morphophysiological Sciences, State University of Maringá, Maringá, PR, Brazil.
J Diabetes Complications. 2010 Sep-Oct;24(5):301-5. doi: 10.1016/j.jdiacomp.2009.07.003. Epub 2009 Sep 11.
The acute effect of oral administration of isolated or combined glycerol, pyruvate, and L-lactate on glycemia recovery (GR) during long-term, insulin-induced hypoglycemia (IIH) was compared.
Glycemia of 24 h-fasted rats that received intraperitoneal injection (1.0 U/kg) of regular insulin (IIH group) or saline (COG group) and, 15, 150, or 165 min later, oral saline (control IIH), glycerol (100 mg/kg), pyruvate (100 mg/kg), L-lactate (100 mg/kg), or combined glycerol+pyruvate+L-lactate (each 33.3 or 100 mg/kg) was compared. In addition, for comparative purposes, a group that received glucose (100 mg/kg) was included. Glycemia was measured 180 min after insulin or saline injection. To investigate the participation of the hepatic availability of gluconeogenic substrates to GR, livers from IIH and COG rats that received physiological or supraphysiological concentrations of isolated or combined glycerol, pyruvate, and L-lactate were compared. Liver experiments were done 180 min after insulin or saline injection.
Oral glycerol, pyruvate, and L-lactate (isolated or combined) or glucose promoted GR. Moreover, the best GR was obtained with combined glycerol+pyruvate+L-lactate (100 mg/kg). In agreement, livers that received supraphysiological concentrations of glycerol, pyruvate, and L-lactate (isolated or combined) showed higher glucose release than livers that received physiological concentrations of these substances (isolated or combined).
The best GR obtained with combined administration of glycerol, pyruvate, and L-lactate (100 mg/kg) during long-term IIH was a consequence of the higher liver availability of these substances associated with a maintained liver ability to produce glucose from gluconeogenic substrates.
比较口服甘油、丙酮酸和 L-乳酸单独或联合给药对长期胰岛素诱导低血糖（IIH）期间血糖恢复（GR）的急性影响。
24 小时禁食的大鼠接受腹腔注射（1.0 U/kg）普通胰岛素（IIH 组）或生理盐水（COG 组），然后在 15、150 或 165 分钟后口服生理盐水（对照 IIH）、甘油（100mg/kg）、丙酮酸（100mg/kg）、L-乳酸（100mg/kg）或联合甘油+丙酮酸+L-乳酸（每种 33.3 或 100mg/kg）。此外，为了进行比较，还包括了一组接受葡萄糖（100mg/kg）的大鼠。在胰岛素或生理盐水注射后 180 分钟测量血糖。为了研究肝内糖异生底物对 GR 的可用性的参与，比较了接受生理或超生理浓度的单独或联合甘油、丙酮酸和 L-乳酸的 IIH 和 COG 大鼠的肝脏。肝实验在胰岛素或生理盐水注射后 180 分钟进行。
口服甘油、丙酮酸和 L-乳酸（单独或联合）或葡萄糖均可促进 GR。此外，联合使用甘油+丙酮酸+L-乳酸（100mg/kg）可获得最佳的 GR。同样，接受超生理浓度的甘油、丙酮酸和 L-乳酸（单独或联合）的肝脏比接受这些物质生理浓度（单独或联合）的肝脏释放出更高的葡萄糖。
在长期 IIH 期间，联合使用甘油、丙酮酸和 L-乳酸（100mg/kg）进行最佳的 GR 是由于这些物质在肝脏中的可用性更高，同时肝脏保持从糖异生底物产生葡萄糖的能力。
