Microelectrode studies of Necturus antral mucosa. II. Equivalent circuit analysis

Area of Science:

• Physiology
• Biophysics
• Epithelial Transport

Background:

• Understanding Necturus antral mucosa's electrical properties is crucial for studying gastric physiology.
• Previous research has utilized microelectrode techniques to investigate epithelial tissues.

Purpose of the Study:

• To determine the equivalent circuit parameters of Necturus antral mucosa.
• To calculate electrical resistances and electromotive forces (EMF) of apical and basolateral membranes and the shunt pathway.

Main Methods:

• Intracellular microelectrode impalements (15-50 MΩ) were used in Necturus antral mucosa.
• Transepithelial and cellular potentials were measured.
• Voltage deflections from transepithelial current pulses were analyzed to calculate circuit parameters.

Main Results:

• Apical membrane resistance: 7,300 ± 1,900 Ω×cm², Basolateral membrane resistance: 3,990 ± 1,170 Ω×cm², Shunt resistance: 710 ± 40 Ω×cm².
• Measured potentials: Epithelia -4.1 ± 0.8 mV, Apical -41.8 ± 5.1 mV, Basolateral -45.9 ± 5.0 mV.
• Calculated cell membrane EMFs: Apical -1.2 ± 9.7 mV, Basolateral -69.7 ± 11.3 mV, indicating interior negativity.

Conclusions:

• A low-resistance shunt pathway influences electrical parameters, with current flow from serosa to mucosa.
• The shunt causes hyperpolarization of the apical membrane and depolarization of the basolateral membrane.
• Equivalent circuit parameters provide insights into the electrical behavior of Necturus antral mucosa.