Purpose of OCT2?

Hey Guys;

Well, I understand the purpose of Organic Cation Transporters but, I don't understand what the OCT2 do...
I am probably overthinking it but this description is driving me mad..

"The OCTs translocate dopamine, choline and various drugs including vecuronium, quinine and procainamide. They are ‘uniporters’ (i.e. each protein transporter molecule binds one solute molecule at a time and transports it down its gradient). OCT2 (present in proximal renal tubules) concentrates drugs such as cisplatin (an important anticancer drug, see Ch. 56) in these cells, resulting in its selective nephrotoxicity; related drugs (e.g. carboplatin, oxaliplatin) are not transported by OCT2 and are less nephrotoxic; competition with cimetidine for OCT2 offers possible protection against cisplatin nephrotoxicity (Fig. 8.5)."

Thanks guys.

Don't you just love it when you have 3 days left to revise for an exam which is worth half of one of your modules... D=

Original post by Scienceisgood

Hey Guys;

Well, I understand the purpose of Organic Cation Transporters but, I don't understand what the OCT2 do...
I am probably overthinking it but this description is driving me mad..

"The OCTs translocate dopamine, choline and various drugs including vecuronium, quinine and procainamide. They are ‘uniporters’ (i.e. each protein transporter molecule binds one solute molecule at a time and transports it down its gradient). OCT2 (present in proximal renal tubules) concentrates drugs such as cisplatin (an important anticancer drug, see Ch. 56) in these cells, resulting in its selective nephrotoxicity; related drugs (e.g. carboplatin, oxaliplatin) are not transported by OCT2 and are less nephrotoxic; competition with cimetidine for OCT2 offers possible protection against cisplatin nephrotoxicity (Fig. 8.5)."

Thanks guys.

Don't you just love it when you have 3 days left to revise for an exam which is worth half of one of your modules... D=

What the figure effectively shows is that cisplatin accumulates in OCT2-, not OCT1-positive cells. Cimetidine dose-dependently reduces the risk of cisplatin-mediated apoptosis in OCT2-positive cells, but not in OCT1-positive cells, as cisplatin is not taken up to such a great extent in those cells in comparison to OCT2-positive cells.

Reply 2

Scienceisgood

OP

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Original post by thegodofgod

What the figure effectively shows is that cisplatin accumulates in OCT2-, not OCT1-positive cells. Cimetidine dose-dependently reduces the risk of cisplatin-mediated apoptosis in OCT2-positive cells, but not in OCT1-positive cells, as cisplatin is not taken up to such a great extent in those cells in comparison to OCT2-positive cells.