The action of blood serum of the dog in a condition of tetania parathyreopriva on voluntary muscular tissue compared with that of normal serum

In a recent paper G. M. Wishart gives the results of an attempt to obtain a qualitative estimation of the guanidin in blood by immersing frog muscles in serum. He found that, of six cases observed, the serum of three dogs which had been subjected to parathyroidectomy produced tremors in the muscles of the frog: whereas in three other cases there were no tremors. In some there was prolongation of the normal contraction-an effect similar to that produced by guanidin alone. The serum of a cat affected by tetania parathyreopriva also caused tremors in frog muscle: the serum of normal animals (six dogs and four cats) always proved inactive. The conclusion he draws is that " in certain cases the serum of parathyroidectomnised dogs and cats acts upon the muscles of the frog in the same way as do dilute solutions of guanidin and methylguanidin. But the variations in the susceptibility of the muscles of different frogs renders this biological test unreliable. Fil: Houssay, Bernardo Alberto. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina Received for publication 25th October 1917 fondo