Experimental Hyperthyroidism and Sympathetic Irritability.

Abstract

The object of this experiment was to make a study of the results of Goetsch's “Epinephrin Hypersensitiveness Test” upon dogs rendered experimentally hyperthyroid by feeding desiccated thyroid.

Goetsch's 1 test is based upon the theory that an oversecretion of the thyroid hormone renders the sympathetic nervous system more sensitive to the action of epinephrin. His method is as follows: In a patient at rest such subjective and objective manifestations as nervous symptoms, temperature, pulse, size of pupil, blood pressure, respiration, etc., are noted. Five-tenths cc. of 1-1000 epinephrin is then injected subcutaneously and deeply and the same observations are repeated. Goetsch states that there is usually an early rise in systolic and fall in diastolic pressure, a rise in pulse rate, and an increase of subjective symptoms, if the patient is hyperthyroid. There is no reaction whatever in other patients. Tests were made upon patients with known exophthalmic goitre to test the method, and the results were positive, parallel to the severity of the cases. Saline injections gave no reaction.

Luckhardt and Koppányi, 2 working with dogs, found that subcutaneous injections of epinephrin caused a rise in blood pressure in normal animals if massage of the area followed injection. The reaction was decreased by deep anesthesia and increased by peripheral dilatation (as from local injection of Na No₂). Light paraldehyde anesthesia or deep morphine analgesia did not interfere. These facts were made use of in our experiment.

The present experiments were performed in two series. In Series 1, 28 small dogs were used: 14 normal and 14 dogs previously made hyperthyroid by feeding desiccated thyroid-1 gm. per kilo body weight per day for one week. The dogs were lightly anesthetized with paraldehyde and the blood pressure recorded from the carotid upon a smoked drum.