Different affinities and selectivities of endothelin-1 and endothelin-3 binding to various rat tissues
Jeng, A.Y.; Savage, P.; Soriano, A.; Balwierczak, J.L.
Biochemistry International 22(4): 669-676
1990
ISSN/ISBN: 0158-5231 PMID: 2078195 Document Number: 360392
Inhibition of [125I]endothelin-1 ([125I]ET-1) binding to membrane fractions from various rat tissues by ET-1 and endothelin-3 (ET-3) was investigated. Brain tissue demonstrated a 37-fold higher affinity for ET-1 compared to lung, while a greater than 1000-fold difference in affinity for ET-3 was observed in these two tissues. Furthermore, the ratio of the IC50 value of ET-3 to that of ET-1 in each tissue varied from approximately 2 in brain, kidney and liver to greater than 100 in heart and spleen. These experiments show that the tissues examined have different affinities as well as different selectivities for ET-1 and ET-3.