[Changes of reactivity of rabbit femoral venous rings after 21 d simulated weightlessness].
OBJECTIVE
To study the effects of simulated weightlessness on reactivity of leg veins.


METHODS
Vascular bathing technique was used to measure the contractile responses of rabbit femoral venous rings to Ht, PE and KCl, and the dilatory responses to ACh and SNP after horizontal confinement or head-down tilt confinement for 21 d.


RESULTS
After simulated weightlessness for 21 d, the contractile response of rabbit femoral venous rings to higher concentrations of PE and KCl decreased significantly (P<0.05); the contractile response to Ht also decreased, but not significantly (P>0.05); the dilatory responses to ACh and SNP did not change significantly in both groups.


CONCLUSIONS
Contractile response of rabbit femoral vein decreased after simulated weightlessness for 21 d, which might partly explain the occurrence of orthostatic intolerance in men after space flight.
Liang
Wen-bin
WB
Institute of Space Medico-engineering, Beijing, China.
Jiang
Shi-zhong
SZ
Shen
Xian-yun
XY
Dong
Jian-wen
JW
Ma
Tie-min
TM
Sun
Lei
L
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001835:Body Weight; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005268:Femoral Vein / Q000187:drug effects / Q000502:physiology*; D010656:Phenylephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D012701:Serotonin / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*; D014666:Vasomotor System / Q000187:drug effects / Q000502:physiology*; D018474:Weightlessness Simulation
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D010656:Phenylephrine; D012701:Serotonin; D011189:Potassium Chloride; D000109:Acetylcholine