Abstract
BACKGROUND:
The authors examined the effect of ketamine and its S(+) isomer on isolated human myocardium submitted to hypoxia-reoxygenation in vitro.
METHODS:
The authors studied isometric contraction of human right atrial trabeculae suspended in an oxygenated Tyrode's modified solution at 34 degrees C. Ten minutes before a 30-min hypoxic period followed by a 60-min reoxygenation, muscles were exposed for 15 min to racemic ketamine and its S(+) isomer at 10, 10, and 10 m alone or in the presence of 8.10 m 5-hydroxydecanoate, 10 m HMR 1098 (sarcolemmal adenosine triphosphate-sensitive potassium channel antagonist), 10 m phentolamine (alpha-adrenoceptor antagonist), and 10 m propranolol (beta-adrenoceptor antagonist). Force of contraction at the end of the 60-min reoxygenation period was compared between groups (mean +/- SD).
RESULTS:
Ketamine (10 m: 85 +/- 4%; 10 m: 95 +/- 10%; 10 m: 94 +/- 14% of baseline) and S(+)-ketamine (10-6 m: 85 +/- 4%; 10 m: 91 +/- 16%; 10 m: 93 +/- 14% of baseline) enhanced recovery of force of contraction at the end of the reoxygenation period as compared with the control group (47 +/- 10% of baseline; P < 0.001). Ketamine-induced preconditioning at 10 m was inhibited by 5-hydroxydecanoate (60 +/- 16%; P < 0.001), HMR 1098 (60 +/- 14%; P < 0.001), phentolamine (56 +/- 12%; P < 0.001), and propranolol (60 +/- 7%; P < 0.001).
CONCLUSIONS:
In vitro, ketamine preconditions isolated human myocardium, at least in part, via activation of adenosine triphosphate-sensitive potassium channels and stimulation of alpha- and beta-adrenergic receptors.
Lingua originale | Inglese |
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pagine (da-a) | 1190-1196 |
Numero di pagine | 7 |
Rivista | Anesthesiology |
Volume | 102 |
Stato di pubblicazione | Pubblicato - 2005 |
Keywords
- Adenosine Triphosphate
- Aged
- Aged, 80 and over
- Heart Atria
- Humans
- In Vitro Techniques
- Ischemic Preconditioning, Myocardial
- Ketamine
- Middle Aged
- Myocardial Contraction
- Potassium Channel Blockers
- Potassium Channels
- Propranolol
- Receptors, Adrenergic