Hypochlorite radioiodination of parathyroid peptides (hPTH1-34, [Tyr43]hPTH44-68)

Parathyroid hormone (PTH) radioimmunoassays have conventionally utilized [125I]bPTH1-84 as a radioligand, but more region-specific PTH assays are now possible with the use of recently available synthetic PTH peptides as standards and radioligands. A radioiodination procedure has been developed that utilizes hypochlorite as an oxidant and that is capable of producing PTH tracers of high specific activity (200 to 250 microCi/micrograms), prolonged stability, and excellent immunologic potency. Radioiodinated hPTH1-34 and [Tyr43]hPTH44-68 produced by hypochlorite iodination techniques can be used to develop sensitive and region-specific PTH assays of use in clinical and research situations.