Abnormal heat stress gene hsp70 expression has been demonstrated in organs as well as in cultured cells from spontaneously hypertensive rats and mice. 2. The polymorphism of hsp70, which is localized in the major histocompatibility complex, appears to segregate with a significant portion of hypertension. 3. Abnormal hsp70 expression may lead to anomalies in its feedback regulation, particularly since the steady state level of heat stress protein HSP70 seems to be lower in hypertensive than in normal animals. 4. Another biological consequence could be a modification of the effectiveness of cortisol, which may be involved in metabolic components of the pathogenesis of hypertension.
