Prostanoids and thromboxane production by renal brush border membrane

Abstract

It has been estimated that proximal tubule are responsible for about 7.5% of total kidney prostaglandin PGE₂ production. In the present report we investigated the production of prostanoids and thromboxane by rabbit renal proximal tubule brush border membrane. PGF_2α was the major endogenous prostaglandin produced under basal condition. The addition of exogenous arachidonic acid increased only PGE₂ production. No PGE₂ production was found when vesicles were incubated with indomethacin or at 4 °C, suggesting the involvement of the PGH₂ synthase and PGE₂ isomerase enzymes. Addition of angiotensin II at 10^-6 and 10^-9 mol I^-1 did not affect the endogenous PGE₂ production by brush border membrane. Thus, results of our study demonstrates that the renal proximal tubule brush border membrane has the capacity to produce prostanoids and thromboxane.

Key Words:

• arachidonic acid
• brush border membrane
• prostaglandins
• thromboxane B₂