Gastric acid
The main constituent of gastric acid is hydrochloric acid which is produced by parietal cells (also called oxyntic cells) in the gastric glands in the stomach. Its secretion is a complex and relatively energetically expensive process. Parietal cells contain an extensive secretory network (called canaliculi) from which the hydrochloric acid is secreted into the lumen of the stomach. The pH of gastric acid is 1.5 to 3.5 in the human stomach lumen, the acidity being maintained by the proton pump H/K ATPase. The parietal cell releases bicarbonate into the bloodstream in the process, which causes a temporary rise of pH in the blood, known as an alkaline tide.
Feline lower urinary tract disease
Urine pH can be made more acid by increasing protein intake from animal and fish sources. Examples include human table scraps such as beef (steak/hamburger) and fish. Low cost urine test for humans can be used for monitoring and verifying that a cat's pH is below 6.8. A syringe can be used to suck up the urine from the floor when a cat urinates inappropriately and then squirted onto the test strip.