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A specific and sensitive radioimmunoassay for rat C-peptide

International Journal of Pancreatology volume 13, pages 87–95 (1993)Cite this article

Abstract

A sensitive and specific radioimmunoassay for rat serum C-peptide (RCP) has been developed and validated using a guinea pig anti-rat C-peptide antibody to synthetic rat C-peptide. Negligible crossreactivity (<0.01%) to human proinsulin was observed, whereas human insulin, human pancreatic polypeptide (hPP), porcine insulin, porcine C-peptide, bovine insulin, rat insulin, porcine-PP, and glucagon, respectively, did not produce measurable displacement of RCP tracer. Human C-peptide even in a supraphysiological concentration range crossreacted poorly (<0.1%). The sensitivity limit of the assay calculated at ±3 standard deviations was 24.2pM (0.07 ng/mL). RCP standard concentrations ranged from 25–1600pM. The intraassay-and between assay-coefficient of variations (CV) were 3.5–6.1% and 4.1–9.5%, respectively. The mean percentage recovery of RCP added to rat serum samples was 100.8±2%. Serum volume dilution from 25 to 100 μL did not significantly alter the expected RCP level. Migration of rat serum C-peptide and that of synthetic RCP were identical in a Sephadex G-50 chromatographic analysis. The mean fasting and postprandial plasma RCP levels in normal rats were 102±15pM and 485±75pM, respectively. RCP levels following intravenous glucose tolerance test in diabetic and nondiabetic rats were consistent with expected patterns.

In conclusion, we have developed and validated a rat C-peptide assay that is sensitive, simple, and specific for RCP in serum. The assay provides a reliable tool for studies of diabetes using rodent animal models.

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Author notes

  1. Ronald L. Gingerich

    Present address: Department of Pediatrics, Washington University, Box 8116, 63110, St. Louis, MO

Affiliations

  1. Department of Pathology, Washington University, 63110, St. Louis, MO

    Jones O. Akpan, Lamont G. Weide & Ronald L. Gingerich

  2. Department of Internal Medicine (Metabolism Division), Washington University, 63110, St. Louis, MO

    Jones O. Akpan, Lamont G. Weide & Ronald L. Gingerich

Authors
  1. Jones O. Akpan
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  2. Lamont G. Weide
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  3. Ronald L. Gingerich
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Akpan, J.O., Weide, L.G. & Gingerich, R.L. A specific and sensitive radioimmunoassay for rat C-peptide. International Journal of Pancreatology 13, 87–95 (1993). https://doi.org/10.1007/BF02786076

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  • DOI: https://doi.org/10.1007/BF02786076

Keywords

  • Pancreatology Volume
  • Gastric Inhibitory Polypeptide
  • Human Proinsulin
  • Beta Cell Activity