Abstract
Whether or not digitalis effects the epinephrine output rate in any way has been investigated by intravenous administrating digi-tamin, a commercial preparation, into 5 dogs without anaesthetizing, fastening or evoking any pain.
Suprarenal blood was collected by means of the lumbar route me-thod with the previous de-afferentation of the operation field. The epinephrine was determined by the rabbit intestine segment method. The blood sugar by the Hagedorn and Jensen method.
When 0.5 c.c. digitamin per kilo of body weight was applied, the digitalis slowing became manifest, and the blood sugar content was found reduced in a certain scale, which appeared somewhat later than the bradycardia and disappeared simultaneously with the latter, but the epinephrine output rate remained unaffected.
1 c.c. digitamin per kilo was applied, digitalis bradycardia appeared but only transitorily, and sooner or later was replaced by tachycardia. The epinephrine output rate increased decidedly, and hypoglycaemia occurred, but was never profound.
1.5 c.c. and 4 c.c. were dosaged, poisoning was too intensive, so that dogs died within a few minutes; the epinephrine output rate was estimated largely accelerated as 0.0034 mgrm. per kilo per minute from one side gland, that is 0.007 mgrm. from both glands. In a short period the blood sugar remained unchanged.
Briefly stated: So long as digitalis poisoning remains in the bradycardia stage, probably it may be fairly said in the therapeutic stage, the epinephrine output will not be affected at all, but if the poisoning progresses as to cause cardiac acceleration the epinephrine output is necessarily accelerated. And the poisoning more intensive, the acceleration greater.
The dose of slowing cardiac rhythm but of not accelerating the epine-phrine liberation is about one third of the minimum fatal dose.
Digitalis acts to reduce the blood sugar concentration, but never excessively.
