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Scientific Proceedings (131) 



The circulatory depression was due to direct action on cardiac 

 muscle; the depressant material was precipitated by mercury. 

 The residue contained sugar, which was removed by glacial 

 acetic acid. From this residue crystals were obtained which 

 were powerful stimulants to smooth muscle of uterus, intestine, 

 and arteries, caused constriction, followed by dilatation of kid- 

 ney vessels, with slight diuresis and a prolonged rise in blood 

 pressure, from peripheral constriction. In the dog, 0.5 to 5 mg. 

 caused contraction of the uterus, pregnant or non-pregnant; in 

 the rabbit, similar results were obtained with 0.1 to 0.4 mg. 

 Intestinal muscle was affected also, but larger doses were re- 

 quired. Isolated rabbit uterus was strongly stimulated by one 

 part in two millions of this material ; strips of human uterus re- 

 sponded to one part in one million; isolated rabbit gut showed 

 an increase in rhythmic movement and in tone, but never a tonic 

 spasm, and the effect was not influenced by atropine ; in all these 

 preparations, the effect disappeared on substituting fresh solu- 

 tion, and could be brought out repeatedly by adding more of the 

 drug. The physiologic effects were very similar to those of 

 pituitary extract, but, unlike pituitary, could be brought out re- 

 peatedly without weakening or reversal. 



The nature of these crystals remains undetermined. They 

 are organic, are non-nitrogenous, non-glucosidal, freely soluble 

 in water, and melt at 52-58°C. We believe that they are respon- 

 sible for the therapeutic smooth muscle effects of Tang Kuei. 



Other constituents of the drug include (a) a yellowish brown 

 volatile oil, probably identical with the lactone of Sakai (2) 

 which causes contraction of the dog's uterus and intestine, but 

 also produced cardiac depression and severe renal irritation ; 

 (b ) cane sugar of which the root contains about 40 per cent., and 

 which, together with irritation by volatile material, is probably 

 responsible for most of the diuretic effects produced by the drug, 

 though the crystalline material is weakly diuretic; (c) cardiac 

 depressant material, of undetermined nature. 



The crude drug contains volatile oils which act on smooth 

 muscle and produce renal lesions like the emmenagogue oils ; the 

 crystalline active principle is water soluble, and therefore this 

 drug may be more effective, though the volatile material makes 

 it little, if any, safer than the emmenagogue group. 



