title: Impaired blood pressure recovery to hemorrhage in obese Zucker rats with orthopedic trauma.
abstract: We have shown that obese Zucker rats with orthopedic trauma (OZT) exhibit a loss of arteriolar tone in skeletal muscle. We hypothesize that the loss of arteriolar tone in OZT blunts vasoconstrictor responses to hemorrhage, resulting in an impaired blood pressure recovery. Orthopedic trauma was induced with soft tissue injury and local injection of bone components in both hindlimbs in lean (LZT) and OZT (11-13 wk). One day after the orthopedic trauma, blood pressure responses following hemorrhage were measured in conscious control lean, control obese, LZT, and OZT. In another set of experiments, the spinotrapezius muscle of control and trauma animals was prepared for microcirculatory observation. Arteriolar responses to phenylephrine (PE) or hemorrhage were determined. Hemorrhage resulted in similar blood pressure responses in control animals and LZT, but the blood pressure recovery following hemorrhage was blunted in the OZT. In the spinotrapezius, OZT exhibited decreased arteriolar tone and blunted vasoconstrictor responses to PE and hemorrhage. Treatment with glibenclamide improved the blood pressure recovery in the conscious OZT and improved the arteriolar tone, and PE induced vasoconstriction in the spinotrapezius of the OZT. Thus, ATP-dependent K(+) channel-mediated loss of arteriolar tone in OZT blunts the arteriolar constriction to hemorrhage, resulting in impaired blood pressure recovery.
authors: Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, 39216-4505, USA. Lxiang2@umc.edu
authors: Lusha
authors: L
authors: Xiang
authors: Silu
authors: S
authors: Lu
authors: William
authors: W
authors: Fuller
authors: Arun
authors: A
authors: Aneja
authors: George V
authors: GV
authors: Russell
authors: Louis B
authors: LB
authors: Jones
authors: Robert
authors: R
authors: Hester
mesh_terms: D000818:Animals; D001160:Arterioles / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005264:Femoral Fractures / Q000150:complications* / Q000503:physiopathology; D005905:Glyburide / Q000494:pharmacology; D006339:Heart Rate; D006470:Hemorrhage / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D054086:KATP Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D008833:Microcirculation; D018482:Muscle, Skeletal / Q000098:blood supply*; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D010656:Phenylephrine / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D011924:Rats, Zucker; D020127:Recovery of Function; D017695:Soft Tissue Injuries / Q000150:complications* / Q000503:physiopathology; D013997:Time Factors; D014661:Vasoconstriction; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D054086:KATP Channels; D026902:Potassium Channel Blockers; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D005905:Glyburide