AJP - Gastrointestinal and Liver Physiology, Vol 245, Issue 3 364-G368, Copyright © 1983 by American Physiological Society
Cholinergic stimulation of ouabain-sensitive respiration in rat submandibular gland
D. J. Stewart, D. J. Pon and A. K. Sen
Oxygen consumption of slices of rat submandibular gland was monitored with
an oxygen electrode method. Carbachol stimulated an immediate increase in
tissue respiration that was inhibitable by ouabain. The stimulation
required the presence of calcium in the incubation medium and was blocked
by atropine. The calcium ionophore A23187 also stimulated ouabain-sensitive
oxygen consumption in the tissue slices. The results show that the
mechanism using the extra energy during cholinergic stimulation is the
sodium pump. Amiloride at a 1, 10, or 100 microM concentration had no
effect on stimulation of ouabain-sensitive respiration by carbachol. Since
amiloride, which is known to block the sodium reabsorption process in the
ductal segment, has no effect on the stimulation, the increased sodium pump
activity is probably located in the acinar region and is associated with
the primary fluid secretion process.
