Metabolic dependence of the electromyogram of the cat colon

Strips of colon muscle (1 x 10 cm) were exposed to alterations of temperature, to 2,4-dinitrophenol, and were deprived of O2. Cooling reduced slow-wave frequency in proximal colon from 5.2 at 37 degrees C to 3.9, 2.7, 1.2 and 0.5 cycle/min at 34, 30, 25, and 20 degrees C, respectively; all changes were significant (P < 0.05). Heating also reduced slow-wave frequency in proximal colon from 5.2 at 37 degrees C to 5.1, 4.8 (P < 0.05), and 3.3 (P < 0.05) cycle/min at 39, 41, and 43 degrees C, respectively. Hypoxia reduced slow-wave frequency from 4.6 at 95% O2 to 2.8 cycle/min at 0% O2 (P < 0.05). 2,4-Dinitrophenol (10(-4) M) reduced frequency from 5.3 to 2.7 cycle/min (P < 0.05). The results of studies of distal colon were similar. In distal colon cooling reduced the time occupied by migrating spike bursts from 20.7% at 37 degrees C to 11.1% at 25 degrees C, and 7.9% at 20 degrees C (P < 0.05). Hypoxia also reduced the time occupied by migrating spike bursts from 16.7% at 95% O2 to 5.9% at 0% O2 (P < 0.05).