Abstract
The hydraulic conductivity and water driving forces of a rat submandibular gland were measured by the pressure-metric method. A polyethylene tube was inserted into a main duct of a rat submandibular gland and connected to a narrow vertical tube. The level of fluid was monitored by a pressure transducer. Differentiation of the pressure curve with respect to time gave the volume flow curve. A part of relationship between flow and pressure was linear, and its slope gave the hydraulic conductivity of a gland. We compared the values of hydraulic conductivity under three conditions : 1) secretion of the perfused gland evoked by acetylcholine, 2) secretion evoked by Phenylephrine, 3) passive absorption of fluid performed with 0.15 MNaCl+Amiloride 10-5 M. The values of hydraulic conductivity were very high with little difference between the stimulating and resting phases, and their values were about 2.4-2.6 × 10-10 1 sec-1 Pa-1 kg-1.
