Pressure-distension relationship in arteries and arterioles in response to 5 wk of horizontal bedrest

被引:22
作者
Eiken, Ola [1 ]
Kolegard, Roger [1 ]
Mekjavic, Igor B. [2 ]
机构
[1] Karolinska Inst, Swedish Def Res Agcy, SE-17177 Stockholm, Sweden
[2] Jozef Stefan Inst, Dept Automat Biocybernet & Robot, Ljubljana, Slovenia
来源
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY | 2008年 / 295卷 / 03期
关键词
gravity; microgravity; vascular compliance; vascular deconditioning; vascular stiffness;
D O I
10.1152/ajpheart.00576.2008
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
We hypothesized that exposure to prolonged recumbency (bedrest), and thus reductions of intravascular pressure gradients, increases pressure distension in arteries/arterioles in the legs. Ten subjects underwent 5 wk of horizontal bedrest. Pressure distension was investigated in arteries and arterioles before and after the bedrest, with the subject seated or supine in a hyperbaric chamber with either one arm or a lower leg protruding through a hole in the chamber door. Increased pressure in the vessels of the arm/leg was accomplished by increasing chamber pressure. Vessel diameter and flow were measured in the brachial and posterior tibial arteries using Doppler ultrasonography. Electrical tissue impedance was measured in the test limb. Bedrest increased (P < 0.01) pressure distension threefold in the tibial artery (from 8 +/- 7% to 24 +/- 11%) and by a third (P < 0.05) in the brachial artery (from 15 +/- 9% to 20 +/- 10%). The pressure-induced increase in tibial artery flow was more pronounced (P < 0.01) after (50 +/- 39 ml/min) than before (13 +/- 23 ml/min) bedrest, whereas the brachial artery flow response was unaffected by bedrest. The pressure-induced decrease in tissue impedance in the leg was more pronounced (P < 0.01) after (16 +/- 7%) than before (10 +/- 6%) bedrest, whereas bedrest did not affect the impedance response in the arm. Thus, withdrawal of the hydrostatic pressure gradients that act along the blood vessels in erect posture markedly increases pressure distension in dependent arteries and arterioles.
引用
收藏
页码:H1296 / H1302
页数:7
相关论文
共 29 条
[1]   Hip, thigh and calf muscle atrophy and bone loss after 5-week bedrest inactivity [J].
Berg, Hans E. ;
Eiken, Ola ;
Miklavcic, Lucijan ;
Mekjavic, Igor B. .
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY, 2007, 99 (03) :283-289
[2]   Vascular adaptation to deconditioning and the effect of an exercise countermeasure: results of the Berlin Bed Rest study [J].
Bleeker, MWP ;
De Groot, PCE ;
Rongen, GA ;
Rittweger, J ;
Felsenberg, D ;
Smits, P ;
Hopman, MTE .
JOURNAL OF APPLIED PHYSIOLOGY, 2005, 99 (04) :1293-1300
[3]  
Blomqvist C.G., 1983, HDB PHYSL, P1025, DOI [10.1002/cphy.cp020328, DOI 10.1002/CPHY.CP020328]
[4]   PSYCHOPHYSICAL BASES OF PERCEIVED EXERTION [J].
BORG, GAV .
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, 1982, 14 (05) :377-381
[5]   Orthostatic intolerance after spaceflight [J].
Buckey, JC ;
Lane, LD ;
Levine, BD ;
Watenpaugh, DE ;
Wright, SJ ;
Moore, WE ;
Gaffney, FA ;
Blomqvist, CG .
JOURNAL OF APPLIED PHYSIOLOGY, 1996, 81 (01) :7-18
[6]   Arterial morphology and blood volumes of rats following 10-14 weeks of tail suspension [J].
Chew, HG ;
Segal, SS .
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, 1997, 29 (10) :1304-1310
[7]  
Convertino V A, 1990, Exerc Sport Sci Rev, V18, P119
[8]   Vascular functions in humans following cardiovascular adaptations to spaceflight [J].
Convertino, Victor A. ;
Cooke, William H. .
ACTA ASTRONAUTICA, 2007, 60 (4-7) :259-266
[9]   Effects of head-up tilting on baroreceptor control in subjects with different tolerances to orthostatic stress [J].
Cooper, VL ;
Hainsworth, R .
CLINICAL SCIENCE, 2002, 103 (03) :221-226
[10]   Structural and functional remodeling of skeletal muscle microvasculature is induced by simulated microgravity [J].
Delp, MD ;
Colleran, PN ;
Wilkerson, MK ;
McCurdy, MR ;
Muller-Delp, J .
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 2000, 278 (06) :H1866-H1873