Sahoo Biswajit, Srivastava Medha, Katiyar Arpit, Ecelbarger Carolyn, Tiwari Swasti
Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India.
Department of Medicine, Georgetown University, Washington, DC 20057, United States.
World J Diabetes. 2023 Jul 15;14(7):1049-1056. doi: 10.4239/wjd.v14.i7.1049.
Gluconeogenesis is an endogenous process of glucose production from non-carbohydrate carbon substrates. Both the liver and kidneys express the key enzymes necessary for endogenous glucose production and its export into circulation. We would be remiss to add that more recently gluconeogenesis has been described in the small intestine, especially under high-protein, low-carbohydrate diets. The contribution of the liver glucose release, the net glucose flux, towards systemic glucose is already well known. The liver is, in most instances, the primary bulk contributor due to the sheer size of the organ (on average, over 1 kg). The contribution of the kidney (at just over 100 g each) to endogenous glucose production is often under-appreciated, especially on a weight basis. Glucose is released from the liver through the process of glycogenolysis and gluconeogenesis. Renal glucose release is almost exclusively due to gluconeogenesis, which occurs in only a fraction of the cells in that organ (proximal tubule cells). Thus, the efficiency of glucose production from other carbon sources may be superior in the kidney relative to the liver or at least on the level. In both these tissues, gluconeogenesis regulation is under tight hormonal control and depends on the availability of substrates. Liver and renal gluconeogenesis are differentially regulated under various pathological conditions. The impact of one source the other changes, based on post-prandial state, acid-base balance, hormonal status, and other less understood factors. Which organ has the oar (is more influential) in driving systemic glucose homeostasis is still in-conclusive and likely changes with the daily rhythms of life. We reviewed the literature on the differences in gluconeogenesis regulation between the kidneys and the liver to gain an insight into who drives the systemic glucose levels under various physiological and pathological conditions.
糖异生是从非碳水化合物碳底物产生葡萄糖的内源性过程。肝脏和肾脏都表达内源性葡萄糖生成及其输出到循环系统所需的关键酶。我们还应补充一点，最近在小肠中也发现了糖异生现象，尤其是在高蛋白、低碳水化合物饮食的情况下。肝脏葡萄糖释放，即净葡萄糖通量，对全身葡萄糖的贡献已经为人熟知。在大多数情况下，由于肝脏体积庞大（平均超过1千克），它是主要的贡献者。肾脏（每个肾脏刚超过100克）对内源性葡萄糖生成的贡献常常被低估，尤其是按重量计算时。葡萄糖通过糖原分解和糖异生过程从肝脏释放。肾脏葡萄糖释放几乎完全是由于糖异生，而糖异生仅发生在该器官的一部分细胞（近端小管细胞）中。因此，相对于肝脏，肾脏从其他碳源产生葡萄糖的效率可能更高，或者至少处于同一水平。在这两种组织中，糖异生的调节都受到严格的激素控制，并取决于底物的可用性。在各种病理条件下，肝脏和肾脏的糖异生受到不同的调节。一种来源对另一种来源的影响会根据餐后状态、酸碱平衡、激素状态以及其他不太清楚的因素而改变。在驱动全身葡萄糖稳态方面，哪个器官更具影响力仍尚无定论，并且可能随着日常生活节奏而变化。我们回顾了关于肾脏和肝脏糖异生调节差异的文献，以深入了解在各种生理和病理条件下是谁在驱动全身葡萄糖水平。
