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Decreased myogenic reactivity in skeletal muscle arterioles after hypothermic cardiopulmonary bypass.
- Source :
-
The Journal of surgical research [J Surg Res] 1997 Apr; Vol. 69 (1), pp. 40-4. - Publication Year :
- 1997
-
Abstract
- Cardiopulmonary bypass (CPB) is associated with a generalized defect in the intrinsic control of vascular smooth muscle. To determine if myogenic reactivity of skeletal muscle arterioles was altered by CPB, sheep (n = 7) were placed on hypothermic CPB (27 degrees C) for 90 min and hearts were arrested by cold blood cardioplegia ([K+] = 25 mM) for 60 min. Arterioles (70-180 microns) were isolated from the gracilis muscle before (control) and 15 min after CPB. In vitro arteriolar responses were studied with video-microscopy. Myogenic reactivity was examined to stepwise increases in intraluminal pressure from 10 to 100 mm Hg. Mean arterial pressure was decreased from 80 +/- 15 prior to CPB to 55 +/- 4 mm Hg (P < 0.01) 15 min after CPB. Myogenic contraction was observed in control vessels and was markedly attenuated by the protein kinase C inhibitor staurosporine (P < 0.01). CPB decreased myogenic contraction and shifted the pressure-diameter relation upward, suggesting a decrease in the intrinsic tone (both P < 0.05 vs control). CPB reduced contractile responses to the alpha 1-adrenoceptor agonist phenylephrine from -43 +/- 7% to -23 +/- 5% (P < 0.01) and the protein kinase C activator 12-deoxyphorbol 13-isobutyrate 20-acetate (phorbol ester) from -64 +/- 6% to -38 +/- 16% (P < 0.01). CPB-associated decrease in myogenic reactivity of skeletal muscle arterioles is likely due to alterations in protein kinase C and/or downstream signal transduction. This may account in part for reduction in systemic vascular resistance and hypotension associated with CPB.
- Subjects :
- Adrenergic alpha-Agonists pharmacology
Animals
Arterioles drug effects
Arterioles growth & development
Arterioles physiopathology
Enzyme Activation
Enzyme Inhibitors pharmacology
Female
In Vitro Techniques
Muscle, Smooth, Vascular drug effects
Muscle, Smooth, Vascular physiopathology
Phenylephrine pharmacology
Phorbol Esters pharmacology
Protein Kinase C antagonists & inhibitors
Protein Kinase C drug effects
Protein Kinase C metabolism
Sheep
Staurosporine pharmacology
Vasoconstriction
Coronary Artery Bypass
Hypothermia, Induced
Muscle Development
Muscle, Skeletal blood supply
Muscle, Smooth, Vascular growth & development
Subjects
Details
- Language :
- English
- ISSN :
- 0022-4804
- Volume :
- 69
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- The Journal of surgical research
- Publication Type :
- Academic Journal
- Accession number :
- 9202644
- Full Text :
- https://doi.org/10.1006/jsre.1997.5020