Properties and localization of endothelin-1-specific receptors in rat testicles.
The characterization and localization of rat testicular endothelin receptors were studied. Receptor binding assay with radiolabeled members of the endothelin family revealed that endothelin-1-specific receptors were present in rat testes; a maximal binding capacity of 250 +/- 62 fmol/mg protein and a dissociation constant value of 0.35 +/- 0.06 nM were calculated from the Scatchard plot. The affinities for endothelin analogues were endothelin-1 = endothelin-2 much greater than endothelin-3 much greater big endothelin-1 for the membrane-bound receptors. Receptors of endothelin-1 were localized in peritubular myoid cells and interstitial cells of rat testis by 125I-labeled endothelin-1 autoradiography; the receptors were undetectable in spermatogenic cells. The presence of endothelin-1 receptors in the rat testis raises the possibility that one or more of the endothelins may play a physiological role in the regulation of testicular function.
Sakaguchi
H
H
Department of Biological Sciences, Tokyo Institute of Technology, Japan.
Kozuka
M
M
Hirose
S
S
Ito
T
T
Hagiwara
H
H
D000818:Animals; D001667:Binding, Competitive; D016232:Endothelins / Q000378:metabolism; D008024:Ligands; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017466:Receptors, Endothelin; D013737:Testis / Q000378:metabolism*; D014018:Tissue Distribution
D016232:Endothelins; D008024:Ligands; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin