Alteration of murine serum lipase activity after allogeneic bone marrow transplantation

Applying a sensitive colorimetric method for serum lipase activity in murine serum, BALB/c were found to have high levels. By contrast. B6 mice and mice of several other strains studied showed low serum lipase activity. Selecting BALB/c and B6 mice for analysis, we studied the influence of genetic crossing and bone marrow transplantation to investigate mechanisms involved in control of serum lipase activity. Compared to BALB/c, F₁ hybrids of these two strains exhibited decreased serum lipase activity, as did B6 mice, suggesting that serum lipase levels may be genetically determined. High levels of serum lipase behaved as an apparent autosomal recessive trait; an autosomal codominant inheritance could not be ruled out, however. Bone marrow transplantation, using a method based on immunologic elimination of post-thymic cells to prevent graft-vs-host disease, showed that B6→ BALB/c, B6→B6, and BALB/c→B6 had low lipase levels, while BALB/c→ BALB/c had high lipase levels. These findings suggest that transplanted marrow cells can influence the level of serum lipase activity if the marrow comes from a donor bearing an apparent genetically dominant trait, even though bone marrow cells themselves, or their descendents, do not exhibit lipase activity or generate lipase.