Altered expression of alpha-fetoprotein and albumin in early embryonic rat liver upon heat shock.

During rat liver development alpha-fetoprotein (AFP) and albumin (alb) are differentially regulated. Alpha-fetoprotein synthesis starts soon after fertilization whereas the earliest time albumin could be detected is day 17-18. However during normal development trace amounts of albumin mRNA could be detected on day 14 or 15. When 12-13 day old embryonic rat liver cells are given heat shock at 42 degrees C, there is an enhanced expression of albumin mRNA as well as protein. Under heat shock conditions, unlike albumin mRNA, there is specific degradation of alphafetoprotein mRNA. Western blot analysis indicated that AFP that was already present is not affected by heat shock whereas alpha-fetoprotein mRNA is degraded.