Synthesis and Secretion of Plasma Proteins by Isolated Hepatocytes of Analbuminemic Rats

The synthesis and secretion of plasma proteins by isolated hepatocytes from the liver of Nagase analbuminemia rats (NAR) were investigated. NAR hepatocytes did not synthesize any albumin, but showed enhanced synthesis and secretion of several other plasma proteins, including transferrin, hemopexin, ceruloplasmin and fibrinogen. The lag period before the secretion of transferrin in NAR hepatocytes decreased. These findings indicate that the increased concentration of plasma globulins in NAR may be due to their enhanced synthesis and secretion in the liver. Nagase analbuminemia rats (NAR) are a mutant strain established from Sprague-Dawley rats (7). The strain is characterized by the nearly total absence of albumin in the serum. Neither albu-min nor albumin mRNA is detectable in the liver of NAR (2, 3). However, the total serum protein concentration in NAR is almost equal to that in normal rats (/), since the contents of serum glob