Effects of muscimol (A; Group 3, n=5) and baclofen (B; Group 4, n=5) on the renal nerve-stimulation (RNS)-induced changes in perfusion pressure (PP) and noradrenaline efflux (NA Efflux) in the isolated pump-perfused rat kidney. Δ, changes from basal values in response to RNS. Muscimol (3, 10 and 100 μM) and baclofen (3, 10 and 100 μM) were infused into the perfusate at 0.05 ml min−1. *P<0.05, **P<0.01 compared with each control value.