Effect of epinephrine on net lactate uptake by contracting skeletal muscle.
J Appl Physiol (1985)
; 91(6): 2635-41, 2001 Dec.
Article
en En
| MEDLINE
| ID: mdl-11717229
ABSTRACT
The purpose of this study was to determine the effect of epinephrine on net lactate (La(-)) uptake at constant elevated blood La(-) concentration and steady level metabolic rate (O(2) uptake) in the canine gastrocnemius-plantaris muscle in situ. Infusion of La(-)/lactic acid (pH 3.5) established a mean arterial blood La(-) concentration of ~10 mM while normal blood-gas and pH status were maintained as the gastrocnemius-plantaris was stimulated with tetanic trains at a rate of one contraction every 4 s. After steady-state control measures, epinephrine was infused for 35 min at rates that produced a high physiological concentration with (Pro; n = 6) and without (Epi; n = 6) beta-adrenergic-receptor blockade via propranolol. Net La(-) uptake values during the control conditions were not significantly different between trials (Epi 0.756 +/- 0.043; Pro 0.703 +/- 0.061 mmol. kg(-1). min(-1)). Steady level O(2) uptake averaged approximately 69.5 ml. kg(-1). min(-1) for both control conditions and did not significantly change over the course of the experiments in either set of trials. Epi experiments resulted in a significantly reduced net La(-) uptake (0.346 +/- 0.088 mmol. kg(-1). min(-1) after 5 min of infusion) compared with control value at all sample times measured. However, net La(-) uptake was not significantly different from control at any time during Pro (0.609 +/- 0.052 mmol. kg(-1). min(-1) after 5 min of infusion). When the change from the respective control values for net La(-) uptake was compared across time for both series of experiments, Epi resulted in a significantly greater change from control than did Pro. This study suggests that epinephrine can have a profound effect on net La(-) uptake by contracting muscle and that these effects are elicited through beta-adrenergic-receptor stimulation.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Epinefrina
/
Agonistas alfa-Adrenérgicos
/
Músculo Esquelético
/
Ácido Láctico
/
Contracción Muscular
Límite:
Animals
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos