Alterations of Neurohumoral Response to Acute Stress in Spontaneously Hypertensive Rats Subjected to Long-Term Isolation

Hypertension is a serious disease characterized by a sustainedor recurrent increase in blood pressure, which can lead to variouscomplications. Here, we studied the effect of genetically determinedarterial hypertension in rats on their adaptation to long-term isolationand subsequent response to acute restraint stress. Male SHR ratswith spontaneous hypertension were maintained in individual cagesfor 14 weeks. The serum levels of corticosterone, glucose, and pro-and anti-inflammatory cytokines and salivary α-amylase activitywere studied, and the expression of genes associated with the regulationof steroidogenesis in the adrenal glands was evaluated. There wereno significant changes in the parameters of the hypothalamic–pituitary–adrenocorticaland sympatho-adrenal systems after isolation. Nevertheless, thepreliminary isolation significantly affected the response to moderaterestraint stress, including the expression of the regulatory genes Fkbp5 and Star inthe adrenal glands and the content of proinflammatory cytokinesIL-1β and IL-6 in the blood, although the changes in these indiceswere relatively subtle. This may reflect the predisposition of animalsin isolation to develop quite specific stress-related changes.