Continuous intramuscular pH measurement during the recovery from brief, maximal exercise in man

Abstract

Muscle pH and temperature were measured before, and continuously for 30 min after, a 30-s maximal sprint exercise in ten subjects. These measurements were made with a needle-tipped pH electrode and a thermocouple placed in vastus lateralis. Venous blood samples were collected for pH, lactate and catecholamine estimations and measurements were also made of the arterial blood pressure and heart rate. The muscle and venous pH decreased from 7.17 +/- 0.01 (mean +/- SEM) and 7.39 +/- 0.01 to 6.57 +/- 0.04 and 7.04 +/- 0.03, respectively, in response to the exercise. No significant recovery occurred in either pH measurement for 10 min, after which muscle pH increased to 7.03 +/- 0.03 and venous pH to 7.29 +/- 0.01 by 30 min. Muscle temperature increased by 2.1 degrees C with exercise and also failed to return to pre-exercise values by 30 min. Blood lactate concentration increased from 0.75 +/- 0.04 mmol l-1 before exercise to a peak value of 15.76 +/- 0.35 mmol l-1 5 min after completion of the exercise, and then declined slowly to 10.30 +/- 0.61 mmol l-1 by 30 min. Arterial blood pressure increased transiently with exercise but recovered rapidly, whereas the exercise-induced tachycardia was sustained throughout the recovery period. The recovery from the metabolic and cardiovascular responses to maximal sprint exercise in man is incomplete 30 min after cessation of the exercise.

Real time measurement of intramuscular pH during routine knee arthroscopy using a tourniquet

“…McKinley et al 13 used an invasive fibre-optic pH probe to observe a reduction in the pH of the quadriceps muscle of a 37-year-old road traffic accident victim with haemorrhagic shock. Allsop et al 16 directly measured muscle pH using a needle-tipped probe in the vastus lateralis for 30 minutes following a 30-second sprint in ten active subjects. Street et al 17 directly measured pH in the vastus lateralis during a five-minute period of exercise using an invasive microdialysis catheter and the pH-sensitive fluorescent dye 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF).…”

Effects of Lactate on One Class of Group III (CT3) Muscle Afferents

“…We studied a smaller, more physiological range, as the intramuscular increases in temperature, as a result of exercise is typically in the range of 2–3°C (Graven-Nielsen, 2006 ). In humans, the intramuscular temperature increased from 35 to 38°C during exercise (Allsop et al, 1990 ; Ferguson et al, 2006 ). Our results were consistent with previous reports that some muscle afferents decrease firing above 35°C (Ottoson, 1965 ; Hertel et al, 1976 ; Fischer and Schäfer, 1999 ).…”