THE PRODUCTION OF 'SULPHATION FACTOR' BY RAT LIVER

Abstract

SUMMARY Rat liver when treated with bovine growth hormone produced a humoral factor ('sulphation factor') which stimulated cartilage growth directly; the results indicate that this humoral factor differs from growth hormone. Perfusion of rat liver and incubation of rat liver slices with bovine growth hormone stimulated the production of 'sulphation factor' as measured by the uptake of 35S into rat cartilage. The liver required a long exposure to the hormone before the 'sulphation factor' was produced and was still capable of 'sulphation factor' production after growth hormone treatment had ceased. The age and condition of the animal influenced the time necessary for growth hormone to act on the liver and the persistence of its effects. Disruption of liver slices by freezing and thawing, and by homogenization, destroyed their ability to produce 'sulphation factor' on addition of growth hormone.