Putative thyroid hormone receptors in red blood cells of some reptiles.
Putative triiodothyronine (T3) receptors have been detected in the nuclei of red blood cells (RBC) in a number of reptile species. The binding characteristics of T3 receptors in vitro were dissociation constant (Kd) 9.1 to 28.58, 36.8 and 40, and 11.12 and 11.36 pM, and binding capacity (Bmax) 0.12 to 0.37, 0.17 and 0.24, and 0.19 and 0.28 fmol per million cells in the rat snake (Ptyas korros), soft-shelled turtle (Trionyx sinensis), and tokay gecko (Gekko gecko), respectively. These data were obtained in all species using in vitro incubation of whole cell according to current receptor studies on living cells. With modified technique in subsequent experiments, these values of the binding characteristics were seemingly low. The discrepancy was ascribed to the assessment of "free" fraction of hormone which would be used in subsequent calculation.
D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000648:ultrastructure; D004912:Erythrocytes / Q000648:ultrastructure*; D005260:Female; D007457:Iodine Radioisotopes; D008297:Male; D011485:Protein Binding; D011988:Receptors, Thyroid Hormone / Q000032:analysis*; D012104:Reptiles / Q000097:blood*; D012911:Snakes / Q000097:blood; D014426:Turtles / Q000097:blood
D007457:Iodine Radioisotopes; D011988:Receptors, Thyroid Hormone