Influence of spaceflight, hindlimb suspension, and venous occlusion on alpha 1-adrenoceptors in rat vena cava

Sayet, I.; Neuilly, Ghislaine; Mironneau, Jean; Mironneau, C.

doi:10.1152/jappl.1995.78.5.1882

Cited by 26 publications

(23 citation statements)

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“…Purdy et al (1998) reported no significant effect of rat hindlimb suspension on maximal vein response to noradrenaline (jugular and femoral). However, Sayet et al (1995) revealed modifications in the properties of rat vena cava. Alterations to noradrenaline‐induced contraction by decreased affinity to α 1B adrenoreceptors was observed after hindlimb suspension.…”

Section: Discussionmentioning

confidence: 98%

Calf venous volume during stand‐test after a 90‐day bed‐rest study with or without exercise countermeasure

Chantemèle

Pascaud

Custaud

et al. 2004

The Journal of Physiology

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The objectives to determine both the contribution to orthostatic intolerance (OI) of calf venous volume during a stand-test, and the effects of a combined eccentric-concentric resistance exercise countermeasure on both vein response to orthostatic test and OI, after 90-day head-down tilt bed-rest (HDT). The subjects consisted of a control group (Co-gr, n = 9) and an exercise countermeasure group (CM-gr, n = 9). Calf volume and vein cross-sectional area (CSA) were assessed by plethysmography and echography during pre-and post-HDT stand-tests. From supine to standing (post-HDT), the tibial and gastronemius vein CSA increased significantly in intolerant subjects (tibial vein, +122% from pre-HDT; gastronemius veins, +145%; P < 0.05) whereas it did not in tolerant subjects. Intolerant subjects tended to have a higher increase in calf filling volume than tolerant subjects, in both sitting and standing positions. The countermeasure did not reduce OI. Absolute calf volume decreased similarly in both groups. Tibial and gastrocnemius vein CSA at rest did not change during HDT in either group. During the post-HDT stand-test, the calf filling volume increased more in the CM-gr than in the Co-gr both in the sitting (+1.3 ± 5.1%, vs. -7.3 ± 4.3%; P < 0.05) and the standing positions (+56.1 ± 23.7% vs. +1.6 ± 9.6%; P < 0.05). The volume ejected by the muscle venous pump increased only in the CM-gr (+38.3 ± 21.8%). This study showed that intolerant subjects had a higher increase in vein CSA in the standing position and a tendency to present a higher calf filling volume in the sitting and standing positions. It also showed that a combined eccentric-concentric resistance exercise countermeasure had no effects on either post-HDT OI or on the venous parameters related to it.

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Section: Discussionmentioning

confidence: 98%

Calf venous volume during stand‐test after a 90‐day bed‐rest study with or without exercise countermeasure

Chantemèle

Pascaud

Custaud

et al. 2004

The Journal of Physiology

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“…Numerous investigators (6,25,27) have used the HU model to simulate cardiovascular deconditioning in rats. A study by Murison (23) argued that the effects of HU are not a result of an increase in stress due to HU treatment.…”

Section: Discussionmentioning

confidence: 99%

“…Direct evidence for reduced vascular responsiveness has come from animal studies using real and simulated microgravity. Sayette and co-workers (27) found that the sensitivity of the vena cava to norepinephrine (NE) was reduced in rats exposed to microgravity during spaceflight or simulated microgravity in the form of hindlimb unweighting (HU). Delp and co-workers (5,6) found that the maximal contractile response of the isolated rat aorta to several vasoconstrictor agents was reduced by HU.…”

Section: Rats; Blood Vessels; Norepinephrine; In Vivomentioning

confidence: 99%

Vascular hyporesponsiveness in simulated microgravity: role of nitric oxide-dependent mechanisms

Sangha

Vaziri

Ding

et al. 2000

Journal of Applied Physiology

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Simulated microgravity depresses the ability of arteries to constrict to norepinephrine (NE). In the present study the role of nitric oxide-dependent mechanisms on the vascular hyporesponsiveness to NE was investigated in peripheral arteries of the rat after 20 days of hindlimb unweighting (HU). Blood vessels from control rats and rats subjected to HU (HU rats) were cut into 3-mm rings and mounted in tissue baths for the measurement of isometric contraction. Mechanical removal of the endothelium from carotid artery rings, but not from aorta or femoral artery rings, of HU rats restored the contractile response to NE toward control. A 10-fold increase in sensitivity to ACh was observed in phenylephrine-precontracted carotid artery rings from HU rats. In the presence of the nitric oxide synthase (NOS) substrate L-arginine, the inducible NOS inhibitor aminoguanidine (AG) restored the contractile responses to NE to control levels in the femoral, but not carotid, artery rings from HU rats. In vivo blood pressure measurements revealed that the peak blood pressure increase to NE was significantly greater in the control than in the HU rats, but that to AG was less than one-half in control compared with HU rats. These results indicate that the endothelial vasodilator mechanisms may be upregulated in the carotid artery, whereas the inducible NOS expression/activity may be increased in the femoral artery from HU rats. These HU-mediated changes could produce a sustained elevation of vascular nitric oxide levels that, in turn, could contribute to the vascular hyporesponsiveness to NE.

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“…These results are consistent with a previous observation of diminished ␣-receptor density in the vena cava of rats following spaceflight (59) as a potential mechanism for the diminished venoconstriction. Several studies using HU rats have likewise reported a decreased venoconstriction to NE in the vena cava and mesenteric veins (13,18,59,60), but not in jugular and femoral veins (46). Similar to mesenteric arteries, another potential mechanism for spaceflight-associated impairment of venoconstriction is a blunting of intracellular Ca 2ϩ release through the down-regulation of ryanodine receptors (61 The primary unanswered question regarding vascular alterations associated with spaceflight is the stimulus for the change.…”

Section: Mechanistic Basis For Diminished Venous Constrictionmentioning

confidence: 99%

Effects of spaceflight and ground recovery on mesenteric artery and vein constrictor properties in mice

Behnke¹,

Stabley²,

McCullough³

et al. 2012

The FASEB Journal

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Following exposure to microgravity, there is a reduced ability of astronauts to augment peripheral vascular resistance, often resulting in orthostatic hypotension. The purpose of this study was to test the hypothesis that mesenteric arteries and veins will exhibit diminished vasoconstrictor responses after spaceflight. Mesenteric arteries and veins from female mice flown on the Space Transportation System (STS)-131 (n=11), STS-133 (n=6), and STS-135 (n=3) shuttle missions and respective ground-based control mice (n=30) were isolated for in vitro experimentation. Vasoconstrictor responses were evoked in arteries via norepinephrine (NE), potassium chloride (KCl), and caffeine, and in veins through NE across a range of intraluminal pressures (2-12 cmH(2)O). Vasoconstriction to NE was also determined in mesenteric arteries at 1, 5, and 7 d postlanding. In arteries, maximal constriction to NE, KCl, and caffeine were reduced immediately following spaceflight and 1 d postflight. Spaceflight also reduced arterial ryanodine receptor-3 mRNA levels. In mesenteric veins, there was diminished constriction to NE after flight. The results indicate that the impaired vasoconstriction following spaceflight occurs through the ryanodine receptor-mediated intracellular Ca(2+) release mechanism. Such vascular changes in astronauts could compromise the maintenance of arterial pressure during orthostatic stress.

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Influence of spaceflight, hindlimb suspension, and venous occlusion on alpha 1-adrenoceptors in rat vena cava

Cited by 26 publications

References 0 publications

Calf venous volume during stand‐test after a 90‐day bed‐rest study with or without exercise countermeasure

Calf venous volume during stand‐test after a 90‐day bed‐rest study with or without exercise countermeasure

Vascular hyporesponsiveness in simulated microgravity: role of nitric oxide-dependent mechanisms

Effects of spaceflight and ground recovery on mesenteric artery and vein constrictor properties in mice

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