Developmental changes in endothelin A and endothelin B receptor subtypes in embryonic chick brains.
The kD and Bmax values for [125I]endothelin-1 ([125I]ET-1) binding to the brain membrane preparations of 3- to 20-day-old chick embryos were compared. The kD values differed only slightly during development. In contrast, the Bmax values varied six-fold during the embryonic stages examined and displayed two distinct peaks, on day 5 (204 +/- 13 fmol/mg protein, n = 3) and day 13 (110 +/- 4 fmol/mg protein, n = 7) of incubation. Displacement of [125I]ET-1 binding to 5- and 13-day-old embryonic brain membrane preparations was carried out using ET-3 and BQ-123, a selective ETA receptor antagonist, as competing ligands. The results suggest that the ETA receptor subtype is primarily synthesized at the beginning of development followed by the production of non-selective ETB receptor subtype at a later time.
Jeng
A Y
AY
Research Department, Ciba-Geigy Corp., Summit, NJ 07901, USA.
Wass
K S
KS
Hsu
L
L
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000254:growth & development* / Q000378:metabolism*; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology*; D017466:Receptors, Endothelin / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D019332:Endothelin-1; D017466:Receptors, Endothelin