title: Repeated exposures to moderately increased intravascular pressure increases stiffness in human arteries and arterioles.
abstract: OBJECTIVE
  The aim was to investigate whether repeated exposures to moderate pressure elevations in the blood vessels of the arms (pressure training) affect pressure distension in arteries/arterioles of healthy individuals.
  
  
  METHODS
  Pressure training and vascular pressure-distension determinations were conducted with the participant (n = 11) seated in a pressure chamber with one arm slipped through a hole in the chamber door. Intravascular pressure was increased by elevating chamber pressure. Before pressure training, one arm was investigated (control arm) during stepwise increases in chamber pressure to 180 mmHg. Diameter and flow were measured in the brachial artery using ultrasonography/Doppler techniques. Thereafter, the contralateral arm underwent pressure training consisting of fifteen 40-min sessions during 5 weeks; local intravascular pressures were elevated by 65-105 mmHg during the sessions. After pressure training, pressure-distension relationships were examined in both the trained arm and the control arm.
  
  
  RESULTS
  Pressure training reduced (P < 0.01) arterial pressure distension by 46 ± 18%. Likewise, the pressure-induced increase in arterial flow was less after (350 ± 249%) than before (685 ± 216%) pressure training. The pressure training-induced reductions in arterial/arteriolar pressure distension were reversed 5 weeks after pressure training.
  
  
  CONCLUSIONS
  Thus, the in-vivo wall stiffness in arteries and arterioles increases markedly in response to intermittent, moderate increments of transmural pressure during 5 weeks. The findings are compatible with the notion that local load serves as 'a prime mover' in the development of vascular changes in hypertension.
authors.affiliation: Department of Environmental Physiology, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden. ola.eiken@sth.kth.se
authors.forename: Ola
authors.initials: O
authors.lastname: Eiken
authors.forename: Roger
authors.initials: R
authors.lastname: Kölegård
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001132:Arm / Q000098:blood supply; D001160:Arterioles / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology; D008297:Male; D018608:Ultrasonography, Doppler; D059289:Vascular Stiffness / Q000502:physiology*; D014664:Vasodilation / Q000502:physiology; D055815:Young Adult