AORTIC CROSSTRANSPLANTATION BETWEEN YOUNG AND OLD RATS - EFFECT UPON THE HEAT-SHOCK PROTEIN-70 STRESS-RESPONSE

In previous studies we demonstrated that restraint, or immobilization stress, resulted in the induction of HSP70 mRNA in the vasculature of rats. This response was confined to the vascular smooth muscle, was as sociated with alpha(1)-adrenergic receptor stimulation, and was attenu ated with age. In the present study, we examined the; influence of tra nsplanting aged vessels into young animals and young vessels into aged animals to determine if this age-related diminution was due to change s intrinsic to the aorta or the result of alterations in the environme nt in which the aorta resides. We demonstrate that restraint-induced H SP70 expression in transplanted vessels is influenced to a greater deg ree by the age of the recipient than by the age of the transplanted ve ssel. Transplantation of aged vessels into young animals leads to pres ervation of the response, whereas transplantation of young vessels int o aged animals leads to attenuation. These findings indicate that the environment in which the vessel resides is a major factor in determini ng this molecular response to stress.