Relation between plasma K+ and ventilation during incremental exercise after glycogen depletion and repletion in man.

AUTOR(ES)

Busse, M W

RESUMO

1. We have examined the relationship between expiratory ventilation (VE), plasma potassium concentration ([K+]P), blood lactate concentration ([Lac-]B), and plasma pH (pHP) in five trained men before and after glycogen depletion and repletion in two successive incremental bicycle ergometer tests (tests A and B). 2. Though pHP was significantly higher after glycogen depletion (in relation to normal or repleted conditions) VE and [K+]P also tended to be higher. 3. There was no constant relation between the magnitude or the direction of change in lactic acidosis, or VE and [K+]P, respectively. Instead, a close temporal relationship between changes in VE and [K+]P was found. 4. A non-linear increase in VE occurred independently of changes in pHP or [Lac-]B, but could be well predicted from a non-linear increase in [K+]P. 5. These findings indicate that lactic acidosis had no deciding effect on exercise ventilation in these experiments. They are consistent with the idea that the potassium increase may contribute to the ventilatory drive during exercise.

Documentos Relacionados

• Capillary pressure during and after incremental venous pressure elevation in man.
• Elevated muscle glycogen and anaerobic energy production during exhaustive exercise in man.
• Neural control of cardiovascular responses and of ventilation during dynamic exercise in man.
• Effect of muscle glycogen depletion on in vivo insulin action in man.
• Dissociation between lactate and proton exchange in muscle during intense exercise in man.