Restraint stress caused tachycardia and pressor responses that were greater in spontaneously hypertensive rats compared with normotensive rats, indicating an impaired coping mechanism in hypertension.
Does restraint stress affect cardiovascular regulation differently in spontaneously hypertensive rats compared to normotensive rats?
Spontaneously hypertensive rats exhibit an impaired coping mechanism to restraint stress compared to normotensive rats, suggesting that a reduced capacity to cope with stress may affect cardiovascular regulation in hypertension.
With the use of a restraint stress paradigm, both normotensive Wistar-Kyoto (WKY ) rats and spontaneously hypertensive rats (SHR) underwent acute (1-hour restraint in a Perspex tube), chronic (1-hour restraint for 10 consecutive days), or no-restraint (control) stress. Rats experiencing chronic restraint were previously implanted with telemetric probes to measure heart rate and blood pressure. Basal (prestress session) cardiovascular variables did not change during the course of the study (SHR: mean arterial pressure 129+/-1 mm Hg, heart rate 288+/-4 bpm; WKY rats: mean arterial pressure 103+/-1 mm Hg, heart rate 285+/-3 bpm). Restraint caused tachycardia and pressor responses in the WKY rats and SHR, but these effects were greater in the hypertensive strain. The duration of restraint-induced tachycardia did not change in the WKY rats between acute and chronic stress; however, a graded reduction in the duration of restraint-induced tachycardia occurred in the SHR, decreasing to WKY rat levels by day 7 of the 10-day regimen. These data indicate that although the WKY rats can effectively "cope" within a single period of restraint, the coping mechanism is apparently impaired in the SHR compared with the WKY rats. A reduced capacity to cope with processive stressors may thus have an affect on cardiovascular regulation and represent an additional risk factor in hypertension.
McDougall et al. (Sat,) conducted a other in Hypertension. Restraint stress vs. No-restraint (control) was evaluated on Heart rate and blood pressure (tachycardia and pressor responses). Restraint stress caused tachycardia and pressor responses that were greater in spontaneously hypertensive rats compared with normotensive rats, indicating an impaired coping mechanism in hypertension.