Functional integrity of fetal rat liver explants cultured in a chemically defined medium

Abstract

A technique is described for the rapid preparation of large numbers of fetal rat liver explants for the study of developmental changes. Uniform pieces (1 mm 3) of liver at 16 and 20 days of gestation were cultured for 3 days in a chemically defined medium in the absence of serum or exogenous proteins. Explants of both gestational ages appeared morphologically normal at the end of 3 days. Net uptakes of glucose remained relatively constant over the culture period. There was an initial loss of protein and DNA which could be largely accounted for by loss of erythropoietic cells. After the first or second day in culture, the DNA content of the explants remained constant. The amount of nonsedimentable protein (nonerythrocyte) released into the medium was 16 to 20 μ per explant per day. Between 40 and 50% of this protein was identified as albumin and α-fetoprotein by immunologic and electrophoretic techniques. A minor protein component was identified as transferrin. These proteins, normally secreted into amniotic fluid, were released in amounts that markedly exceeded their concentrations in the explant. This release was blocked by the presence of cycloheximide in the culture medium. This technique provides a simple method for maintaining viable fetal liver explants in a chemically defined medium, and should be useful for studying metabolic development in antenatal liver.