Endothelin-1 receptors in rat renal glomeruli.
Renal glomeruli form a dynamic structure capable of regulating the glomerular filtration rate (GFR). To explore possible regulating effects of endothelin-1 (ET-1) upon glomerular functions, the presence of specific ET-1 receptors and the biological actions of ET-1 were studied in isolated rat renal glomeruli. The specific binding of [125I]ET-1 to glomeruli was time and temperature dependent. Scatchard analysis of the binding data indicated the presence of a single class of high-affinity binding sites with the apparent dissociation constant of 8.3 nM and the maximal binding capacity of 1.5 pmol/mg protein. ET-1 stimulated prostaglandin (PG) E2 production in glomeruli with the time course and the concentration dependency similar to those found in [125I]ET-1 binding to glomeruli. These results indicate the presence of high-affinity binding sites for ET-1 linked to PGE2 production in glomeruli, suggesting a possible role of ET-1 in the regulation of glomerular function.
Orita
Y
Y
Department of Medicine, Osaka University Medical School, Japan.
Fujiwara
Y
Y
Ochi
S
S
Takama
T
T
Fukunaga
M
M
Yokoyama
K
K
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D016232:Endothelins; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007678:Kidney Glomerulus / Q000378:metabolism*; D008297:Male; D010455:Peptides / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
D016232:Endothelins; D007457:Iodine Radioisotopes; D010455:Peptides; D011956:Receptors, Cell Surface