what is the co-transporter of Glucose in proximal tubule in kidneys?

Na is co-transported with the glucose in the proximal tubule.

Sodium-dependent Glucose Transpoters (SGLT). Humans have at least three variants in the proximal tubule, SGLT1, SGLT2, and SGLT3. Because they transport both glucose and sodium, they are considered a type of 'co-transporter' or 'symporter.'

The GLUT proteins ARE NOT co-transporters, as they only transport sugars. The GLUTs are sometimes called 'sodium-indepedent' glucose transporters.

the protein glucose transporter - GLUT 1.

I can really only help with the first part, the composition of the blood and the glomerular filtrate are identical in terms of fluids and solutes, the major difference in a healthy individual is that no albumins, erythrocytes or leucocytes are ever found in the glomerular filtrate. Sorry I can't give you more than that. :(