AN IMPROVED RADIOIMMUNOASSAY FOR THE DETERMINATION OF CANINE GROWTH-HORMONE BASED ON COMMERCIALLY AVAILABLE REAGENTS

Determination of canine growth hormone (cGH) is of importance when eva luating the growth hormone status in dogs, for instance when diagnosin g pituitary dwarfism and acromegaly. At present, analysis for the cGH content in canine blood has mainly been restricted to specialized labo ratories which have had the capacity to develop suitable methods. We t herefore formulated the objective of the present study to be the devel opment of a generally accessible method utilizing commercially availab le reagents. We describe a radioimmunoassay (RIA) for the determinatio n of cGH which was based on reagents developed for the determination o f porcine growth hormone (pGH), thereby drawing benefit from the simil arity between growth hormones from the two species. The RIA method was characterized by satisfying precision and accuracy parameters: intra- and inter-assay coefficients of variation (CV%) were 4-27 % and 4-20 %, respectively, depending on the cGH concentration of the samples. Re covery of added cGH and parallelism between standard curve and sample dilutions were acceptable, thus indicating identity between the calibr ator system and the material under investigation (i.e. plasma samples) . When measuring individual plasma samples or samples taken during clo nidin response tests from normal dogs, dogs suffering from pituitary d warfism and from dogs suffering from acromegaly, the results were comp arable with previous findings.