Calcitonin and calcium ionophores: cyclic AMP responses in cells of a human lymphoid line.

Abstract

Receptors for calcitonin, as assayed by the specific binding of 'SI-labeled salmon calcitonin and stimulation of cyclic AMP formation, were found in 886 cels derived from a human lymphoid line. The affinity of calcitonin from different species and of various analogues of human calcitonin for the binding sites and their ability to stimulate cyclic AMP formation were closely related to their hypocalcemic activity and presumably reflected biological properties of the hormones. Cell Culture, Isolation, and Incubation. The 8866 cells were derived from a patient with chronic myelogeneous leukemia (6) and were generously provided by S. J. Marx (NIAMDD). They were cultured in RPMI 1640 medium with 2 mM L-glutamine, supplemented with 10% fetal calf serum (vol/vol; Gibco, Glasgow, Scotland) and 0.5 ,ug of neomycin sulfate per ml, under a humid atmosphere of 95% air/5% CO2 at 370. Cells were fed two to three times weekly by 1:3 dilution in fresh growth medium. The cells were harvested at the late phase of exponential growth by sedimentation for 10 min at 300 X g at 40, washed three times in the incubation medium, and resuspended to a density of 107 cells per ml.The incubation medium contained 25 mM The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

Human placental calcitonin receptors

“…Like the CT receptor of other target cells or tissues, the placental CT receptor has a high affinity for salmon CT, the relative binding potencies of CTs derived from other species are maintained and non-related peptides do not bind. Furthermore, the placental receptor displays poorly reversible binding, characteristic of CT binding in all tissues studied [7,10,20,39,40].…”

“…Subsequent investigations have shown that the osteoclast [2][3][4][5] and renal tubular cells [6][7][8][9] are major target cells. Nevertheless, a number of other tissues possess CT receptors, including brain [10][11][12], lung [13], testes [14], and trout gill [15] as well as cell lines derived from a wide range of neoplasias including human breast [16], lung [17], and renal carcinoma [18], leukaemia [19,20], teratocarcinoma [21] and osteogenic sarcoma [22]. However, none of these has provided a substantial source of receptor because of either low specific binding activity, scarcity of tissue, or both.…”

Converting the Highly Amyloidogenic Human Calcitonin into a Powerful Fibril Inhibitor by Three-dimensional Structure Homology with a Non-amyloidogenic Analogue

“…After being washed, cells were incubated for 15 min at 310 K in the presence of peptide solutions. After aspiration of the medium, cAMP was extracted from the monolayers with 500 ml of icecold 95% ethanol, 1 mM HCl for 1 h at 283 K. Extracts were then concentrated in a SpeedVac and reconstituted, and cAMP was determined by radioimmunoassay as described (28).…”

Studies of the mechanism by which 3,5,3'- triiodothyronine stimulates 2-deoxyglucose uptake in rat thymocytes in vitro. Role of calcium and adenosine 3':5'-monophosphate.

“…Many studies in cells from different tissues have indicated that thyroid hormones are inactive in this regard (28)(29)(30)(31)(32)(33). On the other hand, T3 in vitro has been found to increase the cAMP concentration in spermatozoa from Macaca mulatta (34), and thyroxine to act similarly in rat osteogenic sarcoma cells in culture (17).…”