Characterization and quantitative topographical distribution of salmon calcitonin-binding sites in rat kidney sections

AbstractRenal binding sites for labelled salmon calcitonin (sCT) were studied using cryostat sections and autoradiography. Increasing concentrations of unlabelled sCT inhibited 125I-sCT binding. 125I-sCT bound to a single site with a Kd of 2 nM and a number of sites of 220 fmolmg protein. Mammalian calcitonins had low affinities and peptides unrelated to CT were devoid of any significant affinity for 125I-sCT receptors. Auto-radiograms disclosed a high concentration of 125I-sCT receptors mainly located in the outer medulla and heterogeneously in the renal cortex. The distribution of specific binding sites is in agreement with the current concepts of renal action of calcitonin

Structure of chicken calcitonin predicted by partial nucleotide sequence of its precursor

AbstractDNA complementary to chicken ultimobranchial gland mRNA was cloned into the Pst I site of plasmid vector pBR322. A plasmid was selected by DNA-mRNA hybridization. We report here the partial nucleotide sequence of chicken calcitonin mRNA and the deduced complete amino acid sequence of chicken calcitonin