Serum amyloid A proteins (SAAs) are a family of homologous apolipoproteins of high density lipoprotein (HDL). They can be divided into two groups. The first group consists of the acute phase SAA1 and SAA2 that associate with HDL during inflammation and remodel the HDL particle by displacing apolipoprotein A1. The second group consists of constitutively expressed SAA4 and SAA5 that exist as minor apolipoproteins on HDL but make up more than 90% of the total SAA during homeostasis.

Serum amyloid A proteins (SAAs) are a family of homologous apolipoproteins of high density lipoprotein (HDL). They can be divided into two groups. The first group consists of the acute phase SAA1 and SAA2 that associate with HDL during inflammation and remodel the HDL particle by displacing apolipoprotein A1. The second group consists of constitutively expressed SAA4 and SAA5 that exist as minor apolipoproteins on HDL but make up more than 90% of the total SAA during homeostasis.

Strain specific analysis of SAA1 mRNA expression in wild-type C57BL/6 mice and B-hSAA1 mice by RT-PCR. Liver RNA were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hSAA1 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human SAA1 primers. Mouse Saa1 mRNA was detectable only in wild-type C57BL/6 mice. Human SAA1 mRNA was detectable only in homozygous B-hSAA1 mice but not in wild-type mice.