Tachykinin P-type Binding Sites in Dog Kidney

Substance P (SP) has potent natriuretic and diuretic properties, increases renal blood flow and decreases renin release in dog kidney [1–3]. It has been suggested that some of the effects of SP in kidney result from bradykinin release [3] or increases in renal cAMP levels [4]. More recently it has been shown that SP mediated vasodilatation in renal arteries is endothelium-dependent [5] and is probably mediated by release of endothelium-derived relaxing factor (EDRF) [5,6]. In this study autoradiographic techniques with [ 125I] Bolton-Hunter substance P (BHSP) have been used to determine the localization of BHSP binding sites in dog kidney sections.