Geer B W, McKechnie S W, Langevin M L
J Nutr. 1983 Aug;113(8):1632-42. doi: 10.1093/jn/113.8.1632.
Dietary sucrose and ethanol are potent modulators of sn-glycerol-3-phosphate dehydrogenase (GPDH) in the third instar larvae of Drosophila melanogaster. When added to modified Sang's medium C, 428 mM ethanol and 146 mM sucrose each increased the GPDH tissue activity more than 90% and GPDH cross-reacting material (CRM) more than 50% over the levels found in larvae fed the 14.6 mM sucrose control diet. When fed together, ethanol and sucrose exerted synergetic effects on GPDH activity and CRM. The activity of glycerol-3-phosphate oxidase was also stimulated by dietary ethanol and sucrose, indicating that the glycerol-3-phosphate cycle was operating in the larvae. Dietary ethanol caused similar shifts in the NADH:NAD+ ratio in wild-type and Gpdh null larvae, suggesting that the maintenance of the cofactor equilibrium is not the primary function of GPDH in larvae. Increases in triacylglycerol content associated with the administration of ethanol and sucrose to larvae suggested that the formation of glycerol-3-phosphate for use in lipid synthesis is an important function of GPDH in larvae. Because ethanol is a constituent of the natural diet of D. melanogaster, nutritional modulation of GPDH is postulated to be an important aspect of the adaptation of the species to its environment.
膳食中的蔗糖和乙醇是黑腹果蝇三龄幼虫中甘油-3-磷酸脱氢酶（GPDH）的有效调节剂。当添加到改良的桑氏培养基C中时，428 mM乙醇和146 mM蔗糖各自使GPDH组织活性比在喂食14.6 mM蔗糖对照饮食的幼虫中发现的水平增加超过90%，使GPDH交叉反应物质（CRM）增加超过50%。当一起喂食时，乙醇和蔗糖对GPDH活性和CRM产生协同作用。甘油-3-磷酸氧化酶的活性也受到膳食乙醇和蔗糖的刺激，表明甘油-3-磷酸循环在幼虫中起作用。膳食乙醇在野生型和Gpdh基因敲除幼虫中引起类似的NADH:NAD+比值变化，表明辅因子平衡的维持不是幼虫中GPDH的主要功能。给幼虫喂食乙醇和蔗糖后三酰甘油含量增加，表明用于脂质合成的甘油-3-磷酸的形成是幼虫中GPDH的重要功能。由于乙醇是黑腹果蝇天然饮食的成分，GPDH的营养调节被认为是该物种适应其环境的一个重要方面。
