This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The pancreas used in medicine is obtained from the pig, Sus scrofa, Linne (N.O. Ungulata).
The pancreas is a gland, weighing (in man) from 60 to 100 grammes, situated near the stomach in a depression formed by the duodenum to which it is closely attached, and into which it discharges its secretion, the pancreatic juice, by means of a principal branching excretory duct called the pancreatic duct. Immediately after the introduction of food into the stomach, the pancreas begins to produce its secretion, which in the case of man averages about 150 grammes a day. The epithelial cells of the small intestine produce a substance termed prosecretin which, when acted upon by dilute hydrochloric acid, yields a hormone, secretin; this passes into the blood and causes the stimulation of the pancreas. The pancreatic juice contains xanthine, guanine, leucine, sodium carbonate and other substances, together with the zymogens of four enzymes, but not the enzymes themselves, these being liberated from the zymogens by means of the enzyme, enterokinase, which is present in the duodenum.
The pancreatic digestion of food is effected by the following three enzymes which act best in neutral or slightly alkaline solution: (i) Trypsin, which digests proteids. (ii) Amylase (amylopsin), which digests starch by converting it into maltose, (iii) Lipase (steapsin), which digests fats by converting them into glycerin, and fat-acids, which unite with the alkalies to form soaps. Commercial pancreatin is a mixture of these enzymes with other substances.