Stress-induced attenuation of the hypercapnic ventilatory response in awake rats.
نویسندگان
چکیده
To test the hypothesis that stress alters the performance of the respiratory control system, we compared the acute (20 min) responses to moderate hypoxia and hypercapnia of rats previously subjected to immobilization stress (90 min/day) with responses of control animals. Ventilatory measurements were performed on awake rats using whole body plethysmography. Under baseline conditions, there were no differences in minute ventilation between stressed and unstressed groups. Rats previously exposed to immobilization stress had a 45% lower ventilatory response to hypercapnia (inspiratory CO(2) fraction = 0.05) than controls. In contrast, stress exposure had no statistically significant effect on the ventilatory response to hypoxia (inspiratory O(2) fraction = 0.12). Stress-induced attenuation of the hypercapnic response was associated with reduced tidal volume and inspiratory flow increases; the frequency and timing components of the response were not different between groups. We conclude that previous exposure to a stressful condition that does not constitute a direct challenge to respiratory homeostasis can elicit persistent (> or =24 h) functional plasticity in the ventilatory control system.
منابع مشابه
Neonatal stress and attenuation of the hypercapnic ventilatory response in adult male rats: the role of carotid chemo- and baroreceptors
Neonatal maternal separation (NMS) is a form of stress which disrupts respiratory control development. Awake adult male rats previously subjected to NMS show a ventilatory response to hypercapnia (HCVR; FICO2 = 0.05) 47% lower than controls; however, the underlying mechanisms are unknown. To address this issue, we first tested the hypothesis that carotid bodies contribute to NMS-related attenua...
متن کاملNeonatal stress and attenuation of the hypercapnic ventilatory response in adult male rats: the role of carotid chemoreceptors and baroreceptors.
Neonatal maternal separation (NMS) is a form of stress that disrupts respiratory control development. Awake adult male rats previously subjected to NMS show a ventilatory response to hypercapnia (HCVR; Fi(CO(2)) = 0.05) 47% lower than controls; however, the underlying mechanisms are unknown. To address this issue, we first tested the hypothesis that carotid bodies contribute to NMS-related atte...
متن کاملNeonatal maternal separation induces sex-specific augmentation of the hypercapnic ventilatory response in awake rat.
Neonatal maternal separation (NMS) is a form of stress that exerts persistent, sex-specific effects on the hypoxic ventilatory response. Adult male rats previously subjected to NMS show a 25% increase in the response, whereas NMS females show a response 30% lower than controls (8). To assess the extent to which NMS affects ventilatory control development, we tested the hypothesis that NMS alter...
متن کاملNeonatal maternal separation alters development of the hypercapnic ventilatory response in awake adult rats
متن کامل
Ventilatory responses to hypercapnia and hypoxia in patients with eucapnic morbid obesity before and after weight loss.
1. To examine the relationship between eucapnic morbid obesity and ventilatory responsiveness to chemical stimuli, we measured hypercapnic and hypoxic ventilatory responses in 29 patients (26 women, three men) before and 3-6 months after gastroplasty. No subject demonstrated resting awake hypercapnia and non suffered from sleep-disordered breathing. 2. Mean weight fell significantly (122.8 +/- ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of applied physiology
دوره 90 5 شماره
صفحات -
تاریخ انتشار 2001