ULTRAFILTRATION OF URINE FOR COLLECTION AND BIOLOGICAL ASSAY OF EXCRETED HYPOPHYSEAL HORMONES

Abstract

A simplified method for concn. and assay of excreted protein hormones has been developed and is described in detail. Urine or aqueous solns. of gonadotrophic hormones are ultrafiltered through a collodion membrane under pressure. The membrane is dissolved in alc.-ether in a centrifuge tube and the ultrafiltered residue is freed from traces of collodion by alternate fresh washes of alcohol-ether and centrifugation. The dried residue is extracted twice with water and the combined extracts are bioassayed. Normal [male] urines so processed and assayed for gonadotrophin in 24-day old [female] mice gave values of 5 to 15 mouse-uterus units/24 hrs. Conditions for greatest rapidity of filtration and completeness of recovery have been worked out and are discussed in detail. In critical tests complete retention by the collodion membrane has been found for known solns. of chorionic gonadotrophin, pregnant mare serum gonadotrophin, and normal [male] urinary gonadotrophin. In preliminary expts. applicability of this technique to the study of other excreted hypophyseal hormones is indicated.