A new bioactive form of human calcitonin
Tobler, P.H.; Dambacher, M.A.; Born, W.; Heitz, P.U.; Maier, R.; Fischer, J.A.
Cancer Research 43(8): 3793-3799
1983
ISSN/ISBN: 0008-5472 PMID: 6861143 Document Number: 198295
Distinct immunoreactive forms of calcitonin (CT), extracted with 2 M acetic acid from two pancreatic tumors, were characterized and identified by gel permeation chromatography and by reverse-phase high-performance liquid chromatography. The extracted CT forms were compared to CT obtained from medullary thyroid carcinoma and from normal thyroid glands, and were, furthermore, analyzed in a rat hypocalcemic bioassay. On gel filtration analysis, two broad peaks coeluting with synthetic human CT-(1-32) and extracted dimeric CT, respectively, were found in variable amounts. An acetonitrile gradient high-performance liquid chromatography system revealed two to three predominant CT peaks. Biologically active monomeric and dimeric CT and the biologically inactive sulfoxide form of human CT-(1-32) have been identified. Moreover, we have detected for the first time a new biologically active CT-like component which was most prominently recognized in a benign pancreatic tumor.