Localization and characterization of renal calcitonin receptors by in vitro autoradiography

Journal Article · Mon Nov 30 23:00:00 EST 1987 · Kidney Int.; (United States)

DOI:https://doi.org/10.1038/ki.1987.287· OSTI ID:5437844

Sexton, P M; Adam, W R; Moseley, J M; Martin, T J; Mendelsohn, F A

Calcitonin receptors were identified in renal cortex and medulla using the radioligand /sup 125/I-salmon calcitonin. Microscopic localization of these receptors revealed binding over medullary and cortical thick ascending limb of the loop of Henle and in distal convoluted tubule. A number of receptor positive cells in the inner medulla were also identified. Characterization of the binding demonstrated a single class of high-affinity binding sites in both the medulla and the cortex with affinity constants of 0.74 +/- 0.09 x 10(9) M-1 and 0.32 +/- 0.05 x 10(9) M-1, respectively, and receptor concentrations of 205 +/- 45 fmol/mg protein and 453 +/- 54 fmol/mg protein, respectively. Competition for /sup 125/I-salmon calcitonin binding by a wide range of calcitonin analogs revealed a close correspondence between the reported biological potencies and activities in the current system. The localization of binding sites within the nephron corresponds to the reported localization of calcitonin-stimulated adenylate cyclase activity and suggests that the receptor mediated actions of calcitonin in the kidney utilize cyclic AMP as a second messenger. In addition, the microscopic identification of specific calcitonin receptors helps the delineation of direct actions of this hormone from those which are indirect.

• Research Organization: Univ. Department of Medicine, Heidelberg, Victoria (Australia)
• OSTI ID: 5437844
• Journal Information: Kidney Int.; (United States), Journal Name: Kidney Int.; (United States) Vol. 32:6; ISSN KDYIA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
AMP
ANADROMOUS FISHES
ANIMALS
AQUATIC ORGANISMS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL LOCALIZATION
BODY
CALCITONIN
CHEMICAL COMPOSITION
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FISHES
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KIDNEYS
KINETICS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SALMON
VERTEBRATES