Effect of Ergotamine Tartrate on the Heat Production of Normal and Thyroidectomized Rabbits.

Abstract

There are available in atropine and pilocarpine a good paralyzing and a good stimulating drug for the parasympathetic nervous system. For the sympathetic nervous system we have in adrenalin a powerful stimulant, but as yet no proven drug which paralyzes the sympathetic or neutralizes the action of adrenalin.

Recently through the work of Stoll 1 a very promising drug, ergotamine (ergotoxin of Dale 2 ), has become available in sufficient amounts and purity to work with. This drug has been shown to have many activities opposite to those of adrenalin. For example, it lowers blood sugar, 3 body temperature and heat production, especially in case of exophthalmic goiter.

The only observations on the effect of ergotamine on heat production in animals which we have been able to find are those of Bouckaert, 4 who noted a rapid fall in heat production following the injection of ½ mg. of ergotamine tartrate in a thyroidized dog from +26.4 to −19 per cent. This same observer was unable to obtain a reduction in a normal dog. It seemed so unlikely that a drug which lowers metabolism in thyroidized animals should not also lower metabolism of normal animals that we were led to repeat this experiment, using rabbits and doses of 1/8, 1/4 and 1/2 mg. of ergotamine tartrate∗ given subcutaneously. In the control rabbits 1 cc. of 0.9 salt solution was injected subcutaneously. The results are given in the following table :

Ergotarnine tartrate in the doses used causes a striking fall in heat production in normal rabbits without the occurrence of detectable untoward effects. The metabolism lowering effect of ergotamine tartrate was evident within an hour after its injection (the exact time of onset was not determined as our shortest observation period was 1 hour) and may last more than 8 hours.