Regulation of Ca45 transfer in rat salivary and lacrimal glands in vitro

Abstract

The transfer in vitro of Ca⁴⁵ either into or out of rat salivary and lacrimal glands is stimulated by sympathetic and parasympathetic agents. The transfer of Sr⁸⁵ in both directions is also similarly stimulated by acetylcholine. The stimulation of Ca⁴⁵ transfer in both directions by acetylcholine is inhibited by Na lack and by metabolic inhibitors such as azide, dinitrophenol, cyanide, mercuric ion, fluoride in absence of Ca and Mg, lack of oxygen, iodoacetate, and low temperatures. The acetylcholine effect on inward transfer is also reduced or inhibited by increased Ca or Sr, or by EDTA, but is apparently not affected by altered concentrations of K or Mg. In contrast, the acetylcholine effect on outward transfer is not affected by altered Ca concentration or addition of EDTA. Exogenous substrate is not necessary for stimulation of movement in either direction.