When the secretion of gastric juice is deficient it may be excited by gastric tonics, such as ten grains of bicarbonate of soda and a drachm of compound tincture of gentian in water shortly before meals, and may be supplemented by the administration of pepsin and hydrochloric acid after meals.
It is not quite certain whether a true pepsin exists in plants, but many trypsins have been discovered, and one form of erepsin, at least, is very widespread.
This amyloid substance is slowly and imperfectly digested by pepsin - digestion being more complete with trypsin and by autolytic enzymes.
Such an enzyme is the pepsin of the stomach of the higher animals.
It is much more powerful than carbolic acid in its inhibitory action upon unorganized ferments such as pepsin or ptyalin.
A third enzyme, the trypsin of the pancreas, possesses the power of both pepsin and erepsin.