A new radioimmunoassay for the midregion of canine parathyroid hormone.
A new radioimmunoassay for canine PTH employs a goat antiserum against native bovine and human PTHs, with either [125I]bPTH-(41-84) or [125I] [tyr43]-hPTH-(43-68) as Tracer. The assay is monospecific for the midregion (44-68) of PTH. Assay of 40-microliters aliquots allowed detection of PTH in 20 of 22 sera from normal dogs, with these normal iPTH levels inhibiting tracer binding by 19-68%. iPTH levels rose markedly after a decrease in serum calcium ion activity induced by intravenous injection of disodium EDTA; the rise could be detected at 3 min and showed two peaks, one at 3-6 min and one at 10-15 min. After parathyroidectomy, PTH immunoreactivity disappeared rapidly from serum. After nephrectomy, iPTH increased many-fold within 12 h. The assay has a similar specificity and sensitivity to our recently described midregion assay for human PTH and should prove useful in studies of normal parathyroid physiology.
D000818:Animals; D002118:Calcium / Q000097:blood; D002417:Cattle; D003429:Cross Reactions; D004285:Dogs / Q000378:metabolism*; D006801:Humans; D009392:Nephrectomy; D010280:Parathyroid Glands / Q000502:physiology; D010281:Parathyroid Hormone / Q000032:analysis* / Q000276:immunology; D010446:Peptide Fragments / Q000032:analysis*; D011863:Radioimmunoassay; D013045:Species Specificity
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D002118:Calcium