Genetic expression of complement factors and alpha 1-acid glycoprotein by liver tissue during senescence

The effect of age on several messenger RNAs coding for non-specific immune factors were determined in liver RNA isolated from 6-, 12-, 24-, 29- and 37-month-old male Fischer Rats. The levels of complement factors C3 and C4, complement protein factor B, and alpha 1-acid glycoprotein were determined by dot blot hybridization using cDNA probes. All four mRNAs increased slightly between 6 and 29 months of age. Only the mRNAs coding for complement factors C3 and C4 decreased significantly after 29 months of age. In addition, Northern blot analysis of the RNA preparations showed that the size of the four mRNA species did not change with increasing age. There was no evidence for age-related changes in the post-transcriptional processing or degradation of the mRNA species coding for complement factors C3 and C4, complement protein factor B, and alpha 1-acid glycoprotein.