Vascular reactivity to norepinephrine and acetylcholine after chronic intermittent hypoxia in mice.
This study assessed the early vascular reactivity changes in mice after exposure to 14 days intermittent hypoxia (IH) with active or inactive sympathetic nervous system (SNS). Hindquarters of mice exposed to 14 days of IH, sham exposed mice or unhandled mice were perfused at constant flow with Krebs-Albumin (5%). Changes in perfusion pressure were assessed after injection of several doses of norepinephrine in anaesthetized mice (active SNS) or in euthanized mice (inactive SNS). Response to several doses of acetylcholine was recorded after precontraction of hindquarter vascular bed by methoxamine in euthanized mice. Vasoconstrictor response was increased after IH for high dose of NE (50 microg) in euthanized mice and for all doses of NE (2-10-50 microg) in anaesthetized mice, but no change in vasodilatation was observed. These findings suggest that 14 days of IH altered vascular reactivity of mice hindquarter in an early pattern. Vasoconstriction was enhanced, particularly with active SNS, while there was no dysfunction of endothelium-relaxation.
Julien
C
C
Laboratoire Hypoxie: Physiopathologie, Faculté de Médecine, 38700 Grenoble, France. cecile.julien@ujf-grenoble.fr
Bayat
Sam
S
Sam
Bayat
B
Lévy
Patrick
P
Patrick
Lévy
L
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001808:Blood Vessels / Q000187:drug effects* / Q000502:physiology; D001835:Body Weight; D004305:Dose-Response Relationship, Drug; D005065:Euthanasia; D006614:Hindlimb / Q000098:blood supply / Q000187:drug effects; D000860:Hypoxia / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009638:Norepinephrine / Q000494:pharmacology*; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects
D000109:Acetylcholine; D009638:Norepinephrine