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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-8-5
pubmed:abstractText
The modulation of beta-adrenoceptor signaling in the hearts of hindlimb unweighting (HU) simulated weightlessness rats has not been reported. In the present study, we adopted the rat tail suspension for 4 wk to simulate weightlessness; then the effects of simulated microgravity on beta-adrenoceptor signaling were studied. Mean arterial blood pressure (ABP), left ventricular pressure (LVP), systolic function (+dP/dtmax), and diastolic function (-dP/dtmax) were monitored in the course of the in vivo experiment. Single rat ventricular myocyte was obtained by the enzymatic dissociation method. Hemodynamics, myocyte contraction, and cAMP production in response to beta-adrenoceptor stimulation with isoproterenol or adenylyl cyclase stimulation with forskolin were measured, and Gs protein was also determined. Compared with the control group, no significant changes were found in heart weight, body weight and ABP, while LVP and +/-dP/dtmax were significantly reduced. The ABP decrease, LVP increase, and +/-dP/dtmax in response to isoproterenol administration were significantly attenuated in the HU group. The effects of isoproterenol on electrically induced single-cell contraction and cAMP production in myocytes of ventricles in the HU rats were significantly attenuated. The biologically active isoform, Gsalpha (45 kDa) in the heart, was unchanged. Both the increased electrically induced contraction and cAMP production in response to forskolin were also significantly attenuated in the simulated weightlessness rats. Above results indicated that impaired function of adenylyl cyclase causes beta-adrenoceptor desensitization, which may be partly responsible for the depression of cardiac function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
569-74
pubmed:meshHeading
pubmed-meshheading:18511523-Adenylate Cyclase, pubmed-meshheading:18511523-Adrenergic beta-Agonists, pubmed-meshheading:18511523-Anesthesia, pubmed-meshheading:18511523-Animals, pubmed-meshheading:18511523-Body Weight, pubmed-meshheading:18511523-Cyclic AMP, pubmed-meshheading:18511523-Electric Stimulation, pubmed-meshheading:18511523-Forskolin, pubmed-meshheading:18511523-Heart, pubmed-meshheading:18511523-Hindlimb Suspension, pubmed-meshheading:18511523-Isoproterenol, pubmed-meshheading:18511523-Male, pubmed-meshheading:18511523-Muscle Contraction, pubmed-meshheading:18511523-Myocardial Contraction, pubmed-meshheading:18511523-Myocytes, Cardiac, pubmed-meshheading:18511523-Organ Size, pubmed-meshheading:18511523-Rats, pubmed-meshheading:18511523-Rats, Sprague-Dawley, pubmed-meshheading:18511523-Receptors, Adrenergic, beta, pubmed-meshheading:18511523-Signal Transduction, pubmed-meshheading:18511523-Weightlessness Simulation
pubmed:year
2008
pubmed:articleTitle
Modulation of {beta}-adrenoceptor signaling in the hearts of 4-wk simulated weightlessness rats.
pubmed:affiliation
Department of Emergency, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't