ABSTRACT
A RIA method for determining human plasma parathyroid hormone (hPTH1-34) was established. This was possible mainly by the production of an antiserum of high liter raised in rabbit against hPTH1-34. The methodological investigation data were listed below: the affinity constant, Ka= 1,95?1010 mol/L; the cross reactivity with each of the three analogous peptides, i.e., hACTH1-34, hCT and hPTH44_68, being all less than 0.005%; the intra- and inter-batch coefficients of variation being 6.0% and 13.0% respectively; the recoveries for different levels of hPTH1_34 being ranged within 83.1 - 102.6%; and the sensitivity being 1.1 pmol/L. The reference value obtained by testing 50 male and 50 female normal adults was 11.7 ?4.4 pmol/L. It has been applied clinically for patients with various endocrine diseases including hyper- and hypoparathyroidisms and metabolic bone diseases especially in the aged population and the results fitted well with clinical diagnosis.