Abstract
There has been a growing conviction among physiologists and pharmacologists that the reaction of an organ to stimulation will vary, within certain limits, with the state of tonus of the organ at the time of excitation. This conviction applies to drugs involving the autonomic nervous system, but by no means confined to them. A good part of the work has been done on strips of extirpated muscle, or the nerves of the organ have been cut, or numerous drugs influencing the autonomic system have been used in succession, so that, the results must be interpreted in the light of altered physiologic status.
Our work was done on a series of normal dogs trained to lie perfectly quiet under no restrain. A fine balloon at the end of a duodenal tube was passed by mouth (the dogs offer very little resistance after the first 3 or 4 times) and the duodenal tube was connected to a water manometer. The balloon was inflated with 100 cc. of air and the fluctuations of the manometer levels were recorded on a slowly revolving Kymograph. After a suitable control period an injection of 5 m. of 1:1000 Parke Davis Adrenalin was given intracutaneously, in the leg, forming a wheal. (Intracutaneous injection was chosen because a mild relatively prolonged action was desired.)
Controls. The animals' gastric functions were established over a period of one to two weeks under daily observation. They showed: (1) That hunger contractions in a starving animal last from 30 to 50 minutes, and periods of active motility are separated from each other by periods of relative quiescence. (2) These periods of quiescence last from 1 to 1½ hours. In a few instances, however, they were as short as 45 minutes. (3) There was at no time a complete relaxation of the stomach in a starving animal.
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