Chinese Journal of Physiology

THE EPHEDRINES ON NASAL MUCOSA ~ 97

mucosa on repeated injections of the same dose were not identical. These variations might be due to delayed absorption of the drug from the circulation, or to varying reflex changes of nasal volume as a result of mechanical irritation of the artery when the drug was being injected. Consequently we adopted intravenous injections of the drugs. Three preliminary experiments were tried for establishment of the method by experimentation with the same and different doses of ephedrine in order to be sure whether the action upon nasal volume was proportionate to the dosage used. RESULTS

I. The effects produced by repeated doses of ephedrine.

In one experiment three repeated injections of 0.2 mg per kg at two hour intervals yielded approximately equal nasal responses. Another experiment upon a dog weighing 13.6 kg, was made with a larger doseand the following results were obtained.

B.P. N.V.

Ephedrine 2 mg 28 mm Hg 25 mm » 4 ,, 42. ,, 5l DB op 18 24 ,,

Both experiments clearly demonstrated increase of nasal volume to correspond almost exactly with the increase of the dosage of ephedrine, this is true although there is seen the usual marked differences in the

blood pressor effects (see table 1).

II. Comparison of ephedrine and ephetonin. Seven dogs, see fig. 1.

a» Nasal volume.

Dosage: 0.17 to 0.23 mg per kg of body weight.

Nasal volume increased simultaneously with shrinkage of the mucosa of the turbinated bodies, and the nasa] accessory sinuses. Nasal volume began to increase immediately after administration of each drug, In the case of ephetonin it reached the maximal effect in 35 to 80 sec., whereas in the case of ephedrine the maximal effect took place after 40 to 120 sec. The difference is due to the fact that while ephedrine in the same time may cause the same degree of shrinkage as ephetonin it is stronger and thus longer in reaching its maximal effect. The effects on blood pressure and shrinkage of mucosa did not go in parallel. The maximal rise of blood pressure was obtained 20 to 30 sec. after intravenous injection of ephedrine, and after