24 Itagaki 



Summary. 



1. Extract of corpus luteum generally produces a distinct increase of 

 tone in the surviving uterus of the rat, rabbit, cat, dog, and guinea-pig. 

 Rarely, however, the opposite effect is produced. 



2. This difference of effect is not due to the condition of pregnancy 

 or non-pregnancy, nor to varying strengths of the extract, but apparently 

 to a difference in different samples of corpus luteum. It would appear, 

 therefore, that there are two principles in the corpus luteum having an 

 antagonistic action upon the contractions of the uterus. 



3. These principles can sometimes be separated by alcohol, the 

 inhibitory material going into alcoholic solution. But this chalonic 

 substance (17), which is soluble in water, is very small in amount. The 

 hormonic substance, on the other hand, which is generally much larger 

 in amount, is not soluble in alcohol nor in chloroform and ether, but 

 is soluble in water. 



4. If we compare the action of corpus luteum extract upon the uterus 

 with its effect upon other forms of plain muscular tissue, we find that it 

 generally produces relaxation of the muscular tissue of the intestine and 

 of the bladder of the rat, but contraction of the whole intestinal tube of 

 the rabbit and kitten ; although, when isolated strips of either the longi- 

 tudinal or circular intestinal muscle of these animals were taken, they 

 showed relaxation. Upon the iris of the frog no change could be observed. 



5. Injection of coi-pus luteum extract into a vein produces but little 

 effect upon the blood-pressure ; if anything, there is a slight fall. 



6. A free secretion of milk is caused from the cut nipple of a lactating 

 animal. 



7. Urinary secretion is not appreciably affected. 



8. I have been unable to obtain any definite proof that the action of 

 corpus luteum upon the uterus is efiected through the nerve-endings either 

 of the sympathetic or of the pelvic nerve. 



The expenses of this investigation and of those described in the two 

 succeeding papers have been assisted by grants from the Carnegie and 

 Moray Research Funds. 



BIBLIOGRAPHY. 



(1) Prenant, Rev. g6n. d. sci., 1898, t. ix. p. 646. 



(2) Stickel, Arch. f. Physiol., 1913, p. 259. 



(3) FucHS, Zeitschr. f. Geb. u. Gyn., 1914, Bd. Ixxv. p. 653. 



(4) GuGGiSBEHG, ibid., p. 231. 



(5) Ott and Scott, Monthly Cyclopaedia and Med. Bull., 1911 and 1912, 

 p. 207; Proc. Soc. Exper. Biol, and Med., 1911-12, vol. ix. p. 64; contrib. from 

 Physiol. Lab., Med.-Chir. Coll., Philadelphia, 1912. 



(6) Magnus, Pfliiger's Arch., 1904, Bd. cii. p. 123. 



(7) Kbhrer, Arch. f. Gyn., 1907, Bd. Ixxxi. p. 160. 



