Cardiovascular morbidity and mortality can be triggered by emotional stress: it can cause development of arterial hypertension. Development of hypertension is also dependent on genetic background. Borderline hypertensive rats (BHR) with respect to Wistar rats (WR) develop larger cardiovascular response to different stress models. Analysis of spontaneous fluctuations of systolic blood pressure (SBP) and pulse interval (PI) (spontaneous baroreceptor reflex, sBRR) permits an insight on baroreflex and central components of stress response. Effect of air-jet stress on cardiovascular mechanisms was evaluated in freely moving WR (nw=6) and BHR (nbhr=6). Experiments in this study conformed to ECC Directive (86/609/EEC). Under general anesthesia (halothane 4% induction, 2% via mask), rats were equipped by an arterial catheter and exposed to 2min stress. At the end of experiment rats were euthanized (thiopentone sodium, 200mg/kg, i.p.). For a time course analysis of cardiovascular response to stress, five regions of SBP/PI tracings were defined: baseline (BASELINE), air-jet stress (S), immediate recovery (IMMED. REC), and recovery period (REC). Concomitant SBP increases and PI shortenings during REC were analyzed separately (DEL RES). The sequence method revealed that in WR during S and IMMED. REC, sBRR sensitivity was maintained, baroreflex effectiveness (BEI) decreased, its operating range (OR) enlarged and the SBP set point was shifted towards higher values. In REC parameters regained baseline values. DEL RES occurred associated with the re-setting of sBRR (Bajić D et al., 2009). During S in BHR the sequence method revealed that sBRR sensitivity was preserved; BEI showed the tendency to increase (0.72±0.08 vs. 0.79±0.09, paired t-test, p=0.16), the set point was shifted towards higher SBP values (139.7±11.3 mmHg vs. 141.3±12.0 mmHg, paired t-test, p=0.009), while the OR increased (523.8±340.4 vs. 1304.4±550.2, paired t-test, p=0.02). During IMMED. REC BEI maintained the increasing tendency with respect to BASELINE (0.72±0.08 vs. 0.78±0.1, paired t-test, p=0.19), SBP set point decreased vs. S (139.7±11.3mmHg vs. 141.3±11.9mmHg, respectively; paired t-test, p=0.008) and returned to the BASELINE level. In REC BEI and OR returned to the BASELINE values. In DEL RES SBP set point and OR were at the BASELINE level. In WR air-jet stress modulates sBRR differentially during the time course of stress and recovery affecting linear and nonlinear BP and PI relationship. BHR manifested different cardiovascular response to stress with respect to WR. It shows different baroreflex engagement, faster recovery of SBP set-point and less prominent form of DEL RES. The baroreflex dominance in stress response can be compared by dominant baroreflex regulatory response to acoustic stimulation (Silvani et al., 2001).