Hemodynamic and neuroendocrine predictors of lower body negative pressure (LBNP) intolerance in healthy young men

• Autorzy: Gasiorowska A. , Nazar K. , Mikulski T. , Cybulski G. , Niewiadomski W. , Smorawinski J. , Krzeminski K. , Porta S. , Kaciuba-Uscilko H.
• Języki publikacji: EN

Abstrakty

EN

Exposure to LBNP results in body fluid shift to lower extremities similarly as under influence of orthostatic stress. In susceptible persons it leads to syncope. For better understanding why certain individuals are more susceptible to orthostatic challenges it seemed necessary to collect more data on hemodynamic and neuroendocrine adjustments occurring before onset of presyncopal symptoms Accordingly, in this study heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (CO), hematocrit, plasma catecholamines, adrenomedullin, ACTH and plasma renin activity (PRA) were measured in 24 healthy men during graded LBNP (-15, -30 and -50 mmHg). Thirteen subjects completed the test (HT group) whereas 11 had presyncope signs or symptoms at -30 mmHg or at the beginning of -50 mmHg (LT group). Comparison of these groups showed that LT subjects had lower baseline total peripheral resistance and higher plasma adrenomedullin. During LBNP plasma catecholamine and PRA increases were even greater in LT than in HT group while plasma adrenomedullin elevations were similar in both groups. Plasma ACTH increased only in LT group following presyncope symptoms. Low tolerant group showed more rapid decline of SV and CO than HT subjects from the beginning of LBNP. It is suggested that measurements of SV at the level of LBNP which did not evoke any adverse symptoms may be of predictive value for lower orthostatic tolerance.

Słowa kluczowe

EN

orthostatic tolerance; catecholamine; hemodynamic response; adrenomedullin; plasma renin

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2005
• Tom: 56
• Numer: 2
• Opis fizyczny: p.179-193,fig.,ref.

Twórcy

autor

Gasiorowska A.

• Polish Academy of Sciences, 5 Pawinskiego str., 02-106 Warsaw, Poland

autor

Nazar K.

autor

Mikulski T.

autor

Cybulski G.

autor

Niewiadomski W.

autor

Smorawinski J.

autor

Krzeminski K.

autor

Porta S.

autor

Kaciuba-Uscilko H.