title: Blood pressure and mesenteric resistance arterial function after spaceflight.
abstract: Ground studies indicate that spaceflight may diminish vascular contraction. To examine that possibility, vascular function was measured in spontaneously hypertensive rats immediately after an 18-day shuttle flight. Isolated mesenteric resistance arterial responses to cumulative additions of norepinephrine, acetylcholine, and sodium nitroprusside were measured using wire myography within 17 h of landing. After flight, maximal contraction to norepinephrine was attenuated (P < 0.001) as was relaxation to acetylcholine (P < 0.001) and sodium nitroprusside (P < 0.05). At high concentrations, acetylcholine caused vascular contraction in vessels from flight animals but not in vessels from vivarium control animals (P < 0.05). The results are consistent with data from ground studies and indicate that spaceflight causes both endothelial-dependent and endothelial-independent alterations in vascular function. The resulting decrement in vascular function may contribute to orthostatic intolerance after spaceflight.
authors.affiliation: Department of Nephrology, Hypertension, and Clinical Pharmacology, Oregon Health Sciences University, Portland, Oregon 97201, USA. hattond@ohsu.edu
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Hatton
authors.forename: Qi
authors.initials: Q
authors.lastname: Yue
authors.forename: Justin
authors.initials: J
authors.lastname: Chapman
authors.forename: Hong
authors.initials: H
authors.lastname: Xue
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Dierickx
authors.forename: Chantal
authors.initials: C
authors.lastname: Roullet
authors.forename: Sarah
authors.initials: S
authors.lastname: Coste
authors.forename: Jean Baptiste
authors.initials: JB
authors.lastname: Roullet
authors.forename: David A
authors.initials: DA
authors.lastname: McCarron
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D008297:Male; D008638:Mesenteric Arteries / Q000033:anatomy & histology / Q000502:physiology*; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D013026:Space Flight; D013152:Splanchnic Circulation / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine