Characterization of Specific Receptors for Calcitonin in Porcine Lung

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 78; no. 6; pp. 3973 - 3975
• Main Authors: Fouchereau-Peron, M., Moukhtar, M. S., Benson, A. A., Milhaud, G.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01.06.1981; National Acad Sciences
• Subjects: Animals; Binding sites; Calcitonin - metabolism; Cell Membrane - metabolism; Cell membranes; Centrifugation; Hormones; Kinetics; Lung - metabolism; Lungs; Membranes - metabolism; P branes; Rats; Receptors; Receptors, Calcitonin; Receptors, Cell Surface - metabolism; Salmon; Swine; Ungulates
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.78.6.3973

The binding of salmon calcitonin was investigated in subcellular fractions obtained from normal porcine lung. Only the membrane fraction (density, 1.14 g/cm3) showed specific binding for calcitonin. Specific binding of125I-labeled salmon calcitonin was competitively inhibited by concentrations of unlabeled homologous hormone in the range 0.01-1 nM. Half-maximal inhibition of binding was observed with 0.12 nM salmon calcitonin. Scatchard analysis of the data suggested the presence of one class of binding sites with a mean affinity constant of 0.9× 1010M-1and a mean receptor number of 40× 108/mg of protein. The binding of salmon calcitonin was highly specific; half-maximal inhibition of binding was observed with 63.8 nM bovine calcitonin, the hormone corticotropin having no effect in this system.