What is coupled with glucose reabsorption using a symporter in the early part of the proximal tubule?

The correct answer will be- sodium ions

Explanation:

The absorption of glucose takes place as a result of the formation of urine in the kidney as a part of the nephron physiology. The absorption of glucose is important to the body as the loss of glucose with urine will cause disease.  

The glucose is absorbed in the proximal convoluted tubule of the nephron where the cotransporter channel called SGLT2 is embedded in the membrane. The SGLT2 symports the sodium along with the glucose where transport of sodium ions drives the process of reabsorption.

Thus, the sodium ion is the correct answer.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: