title: Short-duration increases in intraluminal pressure improve vasoconstrictor responses in aged skeletal muscle feed arteries.
abstract: OBJECTIVE
  We tested the hypothesis that exposure to a short-duration (1 h) increase in intraluminal pressure, to mimic pressure associated with a bout of exercise, would attenuate age-induced impairments of vascular smooth muscle (VSM) constrictor responses in soleus muscle feed arteries (SFA) via the Rho pathway.
  
  
  METHODS
  SFA from young (4 months) and old (24 months) Fischer 344 rats were cannulated and pressurized to 90 or 130 cmH2O for 1 h. Following the 1-h treatment, pressure in P130 arteries was lowered to 90 cmH2O for examination of vasoconstrictor responses to norepinephrine (NE), angiotensin II (Ang II), and phenylephrine (PE). To assess the role of the Rho pathway, vasoconstrictor responses were assessed in the absence or presence of a RhoA-kinase inhibitor (Y27632) or RhoA-kinase activator (LPA).
  
  
  RESULTS
  Vasoconstrictor responses to NE, Ang II, and PE were impaired in old P90 SFA. Pretreatment of old SFA with increased pressure improved vasoconstrictor responses to NE, PE and Ang II. The beneficial effect of the pressure pretreatment in old SFA was eliminated in the presence of Y27632. In the presence of LPA, vasoconstrictor responses to Ang II were improved in old SFA such that responses were not different than young P90 SFA.
  
  
  CONCLUSIONS
  These results indicate that a short-duration exposure to increased intraluminal pressure, to mimic pressure associated with a bout of exercise, attenuates or reverses the age-related decrement in VSM constrictor responses in SFA and that the beneficial response is mediated through Rho kinase.
authors.affiliation: Department of Health and Kinesiology, MS 4243, Texas A&M University, College Station, TX, 77843-4243, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Seawright
authors.affiliation: Department of Medical Physiology, Texas A&M University, College Station, TX, USA.|Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.
authors.forename: Andreea
authors.initials: A
authors.lastname: Trache
authors.affiliation: Department of Medical Physiology, Texas A&M University, College Station, TX, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Wilson
authors.affiliation: Department of Health and Kinesiology, MS 4243, Texas A&M University, College Station, TX, 77843-4243, USA. woodmanc@hlkn.tamu.edu.|Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA. woodmanc@hlkn.tamu.edu.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Woodman
mesh_terms: D000375:Aging / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000577:Amides / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011312:Pressure; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000378:metabolism
chemical_list: D000577:Amides; D011725:Pyridines; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; C108830:Y 27632; D010656:Phenylephrine; D054460:rho-Associated Kinases; D009638:Norepinephrine
keywords: Aging; Fischer 344 rats; Rho kinase; Vasoconstriction