The action of lindane in accelerating the spontaneous release of transmitter at the frog neuromuscular junction

Lindane (5 x 10(-5) M) causes a progressive and marked rise in MEPP frequency at the frog neuromuscular junction. Concentrations over a range of 5 x 10(-6) M to 5 x 10(-4) M were tested. The results suggest that it has two actions in promoting this effect. Its major effect is probably to cause an increase in Ca2+-permeability and a rise in Ca2+ entry. Its second, smaller effect, which persists in the absence of extracellular Ca2+, is probably also because of a rise in [Ca2+]i. The ways in which these effects might be produced and the significance of these findings for explaining the known pharmacological actions of lindane are discussed.