The major histocompatibility complex (MHC) has been linked to encoding for
individual olfactory identity. Experiments in mice and rats proved that beh
avior and mating were, at least in part, determined by genes within the MHC
. This study was aimed at investigating whether sHLA are excreted in human
urine, saliva and sweat. In particular examination of the molecular forms i
n these fluids would give clues to whether break down forms of soluble MHC
molecules might participate in shaping behavior. Major bands of 45, 40, and
23 kD were detectable. Increased levels of sHLA were measured using a quan
titative ELISA in urine shortly before ovulation decreasing to normal level
s thereafter. In animal models strain specific MHC-linked odor cues have be
en detected in urine. Thus, excretion of sHLA in urine might indicate a sim
ilar role for these molecules in humans.