Effects of exposure to high potassium concentration on the longitudinal muscle-myenteric plexus preparation from guinea-pig.

The effect of potassium on the longitudinal muscle-myenteric plexus (LM-MP) preparation from guinea-pig was studied. The strips were exposed to elevated K+ (30 mM, 60 mM, 90 mM, 120 mM or 150 mM). A phasic contraction of the LM-MP was caused by 10 mM K+ or 15 mM K+ followed by an increase of the contractile activity probably due to the increase in acetylcholine release. A higher molarity of K+ produces more marked depolarization in the LM-MP and above 22 mM K+ tetanizing effects were observed. We attempted to demonstrate that opiate-like material could be released when the tissue was exposed to more than 30 mM K+ even though several different neurotransmitters could be liberated by elevated K+ molarities.

An operative system for treatment of electropharmacological signals with a microprocessor.

We describe an operative system in BASIC language for data acquisition, storage and treatment of biological signals (action potential and transmembrane currents) in cardiac electropharmacology/physiology. The hardware includes a digital oscilloscope, a microprocessor, a X-Y Plotter and a disc unit. The operative system includes a main menu from which one can go directly to whatever program for data acquisition, storage, treatment and graphing.