Different dynamics in the HSP70 concentration in
lymphocytes during gestation in primiparous and
pluriparous cows suggest that the occurrence of a
previous gestation may be a factor influencing how the
immune system of a cow handles pregnancy. The effect
of age on HSP expression has been studied in the serum
of nonpregnant women. Rea et al. [30] found that the
ability of cells to respond to stress and synthesize HSP
decreases with increasing age, whereas in a recent
study, Molvarec et al. [13] did not find a negative
correlation between age and HSP70 concentrations in
serum, perhaps due to the narrower age range in this
study. Furthermore, HSP concentrations in lymphocytes
and in serum cannot be directly extrapolated, because
there are, for example, indications that intracellular but
not extracellular concentrations of HSP72 increase in
physiologically stressed humans [8].