Sham Feeding

Sham Feeding 

a method proposed by I. P. Pavlov in 1890 for investigating the role of the central nervous system in the regulation of gastric secretion; this method is also useful in studying other problems in neurophysiology, such as the blood glucose level, the state of food depots, and the distribution of water in the body when swallowed food or water do not enter the gastrointestinal tract.

Sham feeding, like sham drinking, consists in the swallowing of food (or liquid) by an animal whose esophagus has been surgically severed and its ends drawn out to the neck and healed into the skin (such a chronic operation is called an esophagotomy). The experiment is usually performed on a dog, to which a gastric fistula is first applied. Within a few minutes after the beginning of sham feeding, gastric juice begins to flow, secretion of which does not cease for 2–3 hours, even when the sham feeding is short. If sham feeding continues for several hours, one may obtain from the dog up to 1 liter of pure (that is, unmixed with food) gastric juice, which is used for therapeutic purposes.

As I. P. Pavlov and his associates demonstrated, when the vagus nerves—which convey central nervous system impulses to the stomach—are bilaterally severed, secretion of gastric juice during sham feeding is absent. This confirms the reflex nature of the first phase of gastric juice secretion, during which approximately one-fourth of the normal quantity of gastric juice (the so-called initiative juice) is secreted.

REFERENCE

Pavlov, I. P. Polnoe sobranie sochinenii, vol. 5. Moscow-Leningrad, 1952.

O. M. BENIUMOV