- MeSH
- Medical History Taking MeSH
- Drug Therapy MeSH
- Disease Attributes MeSH
- Conservative Treatment methods utilization MeSH
- Craniocerebral Trauma * diagnosis classification complications MeSH
- Humans MeSH
- Vestibulocochlear Nerve Injuries diagnosis physiopathology MeSH
- Wounds and Injuries * classification complications therapy MeSH
- Rehabilitation methods MeSH
- Petrous Bone physiopathology injuries MeSH
- Somatosensory Disorders diagnosis complications physiopathology MeSH
- Temporal Bone physiopathology injuries MeSH
- Vertigo diagnosis etiology therapy MeSH
- Vestibule, Labyrinth * physiopathology injuries MeSH
- Check Tag
- Humans MeSH
Sustained orthostasis elicits the elevation of arterial blood pressure (BP) via sympathetic activation in conscious Wistar rats for at least 2 hours. We tested the hypothesis whether vestibular apparatus plays a role in BP and heart rate (HR) control in response to prolonged gravitational stress. BP and HR responses to 45? head-up for either 2 or 24 hours were monitored by telemetry. Vestibular lesions (VL) were performed by a modified microsurgical-chemical technique. Horizontal BP and HR were not influenced by VL preceding 2-hour tilt. VL abolished the sustained 2-hour BP response to head-up tilt (8.3+/-0.9 mm Hg relative to horizontal values) while suppressed HR transiently only. VL eliminated diurnal BP fluctuations and decreased HR in horizontal position for 24 hours. Head-up tilt for 24 hours increased BP and HR progressively in intact animals, raising their daily average value by 5.6+/-0.7 mm Hg and 22.2+/-6 BPM, respectively. VL resulted in an initial BP rise followed by progressive BP reduction in response to long-term head-up tilt (4+/-2.2 mm Hg) without eliminating the tachycardia (34.4+/-5.4 BPM). Thus, blockade of labyrinthine inputs attenuates the BP responses elicited by both intermediate and long-term gravitational stress of orthostatic type. However, other sensory inputs derived from non-vestibular cues (e.g. proprioceptive, visual, visceral, cutaneous etc.) seem to be effective enough to maintain BP normal.
- MeSH
- Time Factors MeSH
- Circadian Rhythm MeSH
- Financing, Organized MeSH
- Adaptation, Physiological MeSH
- Gravity, Altered MeSH
- Blood Pressure MeSH
- Rats MeSH
- Disease Models, Animal MeSH
- Neurosurgical Procedures MeSH
- Posture MeSH
- Rats, Wistar MeSH
- Reproducibility of Results MeSH
- Heart Rate MeSH
- Telemetry MeSH
- Vestibule, Labyrinth physiopathology injuries MeSH
- Dizziness etiology physiopathology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Comparative Study MeSH
