Progressive Withdrawal of Muscle Nerve Sympathetic Activity Preceding Vaso-Vagal Syncope during Lower-Body Negative Pressure

1996 ◽  
Vol 91 (s1) ◽  
pp. 50-51 ◽  
Author(s):  
Daniel Hayoz ◽  
Georg Noll ◽  
Claudio Passino ◽  
Roger Weber ◽  
Rene Wenzel ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Sympathetic Activity ◽  
Lower Body Negative Pressure ◽  
Lower Body ◽  
Muscle Nerve

Neurohormonal responses to oscillatory lower body negative pressure in healthy subjects

2021 ◽  
Author(s):  
Akanksha Singh ◽  
Shival Srivastav ◽  
Kavita Yadav ◽  
Dinu S. Chandran ◽  
Ashok Kumar Jaryal ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Healthy Subjects ◽  
Lower Body Negative Pressure ◽  
Lower Body

Bradykinin has no acute effect on the response of forearm blood flow to sympathetic stimulation in man

1990 ◽  
Vol 78 (4) ◽  
pp. 399-401 ◽  
Author(s):  
M. J. Cullen ◽  
J. R. Cockcroft ◽  
D. J. Webb
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Negative Pressure ◽  
Enzyme Inhibitor ◽  
Lower Body Negative Pressure ◽  
Acute Effect ◽  
Acute Administration ◽  
Lower Body ◽  
Resistance Vessels ◽  
Sympathetic Responses

1. Six healthy male subjects received 0.9% (w/v) NaCl (saline) followed by incremental doses of bradykinin (1, 3 and 10 pmol/min), via the left brachial artery. Blood flow and the response of blood flow to lower-body negative pressure were measured in both forearms during infusion of saline and each dose of bradykinin. 2. Bradykinin produced a moderate and dose-dependent increase in blood flow in the infused, but not the non-infused, forearm. Lower-body negative pressure produced an approximately 15–20% reduction in blood flow in both forearms, and this response was unaffected by local infusion of bradykinin. 3. Bradykinin, in contrast to angiotensin II, had no acute effect on peripheral sympathetic responses to lower-body negative pressure. We conclude that, in forearm resistance vessels in man, withdrawal of angiotensin II, rather than accumulation of bradykinin, is likely to account for the attenuation of peripheral sympathetic responses after acute administration of a converting-enzyme inhibitor.

The impact of menopausal status on cardiac responses to exercise training and lower body negative pressure

Maturitas ◽  
2017 ◽  
Vol 103 ◽  
pp. 91
Author(s):  
Amanda Q.X. Nio ◽  
Eric J. Stöhr ◽  
Samantha Rogers ◽  
Rachel Mynors-Wallis ◽  
Jane M. Black ◽  
...  
Keyword(s):  
Exercise Training ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Menopausal Status ◽  
Lower Body ◽  
Cardiac Responses ◽  
The Impact

VASOCONSTRICTOR RESPONSE TO LOWER BODY NEGATIVE PRESSURE DURING AUTONCMIC BLOCKADE

1986 ◽  
Vol 18 (supplement) ◽  
pp. S15
Author(s):  
H. L. Smith ◽  
D. L. Hudson ◽  
H. M. Graitzer ◽  
P. B. Raven
Keyword(s):  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Lower Body ◽  
Vasoconstrictor Response

Diaphragm afferent modulation of phrenic motor drive

1987 ◽  
Vol 62 (6) ◽  
pp. 2436-2441 ◽  
Author(s):  
D. L. Fryman ◽  
D. T. Frazier
Keyword(s):  
Negative Pressure ◽  
Phrenic Nerve ◽  
Lower Body Negative Pressure ◽  
Motor Drive ◽  
Lower Body ◽  
Inspiratory Time ◽  
Neural Drive ◽  
Dorsal Rhizotomy ◽  
Bilateral Vagotomy ◽  
Thiopental Sodium

Experiments were performed in eight lightly anesthetized thiopental sodium (Pentothal) cats to examine whether diaphragmatic afferents can significantly alter the neural drive to the diaphragm when the animal is exposed to lower body negative pressure. Moving-time-averaged diaphragmatic electromyograms (EMGma) were recorded and compared before and during exposure to lower body negative pressure in each of three consecutive conditions: C7 spinalization, bilateral vagotomy, and cervical dorsal rhizotomy. Application of lower body negative pressure in C7-spinalized animals resulted in a decrease in inspiratory time and peak diaphragmatic activity compared with control levels. After bilateral vagotomy, EMGma activity was prolonged with the application of lower body negative pressure. However, there was no increase in peak EMGma activity. After transection of the cervical dorsal roots subserving the phrenic nerve, the prolongation of diaphragmatic activity negative was eliminated. Therefore, we conclude that the significant increase in duration of inspiration in response to application of lower body negative pressure in the C7-spinalized, bilaterally vagotomized cat is mediated by phrenic nerve afferents.

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