Effects of large intravenous electrolyte infusions on rat gastric secretion

Abstract

Gastric secretion was studied in pylorus-ligated rats following single large intravenous injections of electrolyte solutions of varying composition, volume, and tonicity. Single large injections of isotonic sodium chloride led to a volume-related increase in the volume and acid output of gastric secretion without any alteration in the acidity of the gastric juice. The tonicity of the injected fluid was a critical controlling factor and in one experiment marked alterations in tonicity exerted more effect on the subsequent secretory response than did simultaneous large alterations in the volume of fluid injected. The solute load per se was not as critical a factor as was the tonicity of the fluid containing it. It was shown that neither the sodium nor the chloride ion was specifically required in the injected fluid for production of this response and that injections of extremely anisotonic solutions caused profound gastric secretory depression. In view of these findings, it is suggested that care be taken to select appropriate control solutions for intravenous injection in experiments involving the pylorus-ligated rat.