Role of endogenous peripheral opioid mechanisms in renal function.

The role of endogenous peripheral opioid mechanisms in renal function was evaluated in normotensive and hypertensive rats. Intravenous naloxone methylbromide, a quaternary opioid antagonist with limited ability to cross the blood-brain barrier, was used to inhibit endogenous peripheral opioid mechanisms. In normotensive rats, the opioid antagonist impaired the normal renal adaptive response to dietary sodium restriction. In spontaneously hypertensive rats, the opioid antagonist did not affect the renal functional responses to acute environmental stress. These data indicate that, depending on the nature of the intervention, a role for endogenous peripheral opioid mechanisms in the renal function responses may be identified.