390 EXPERIMENTAL PHARMACOLOGY 



EXPERIMENT CXIII. 

 Pituitrin. (Guinea Pig, Cat, Dog, Rabbit: Uterine Strip.) 



1. Cats or guinea pigs are preferred. Prepare a uterine 

 strip and record its contractions. (See Experiment CV1, 

 also Figs. 292 and 316.) After the strip is properly 

 weighted and a short record has been taken add to the solu- 

 tion surrounding the strip one cubic centimeter of pituitrin 

 (1 to 20). Do you get a satisfactory contraction! Wait a 

 while, the drum runs at a very slow speed. If after some 

 minutes no change has been produced replace the salt solu- 

 tion with a fresh supply and inject a larger dose of pituitrin. 

 Could you standardize the size of the dose by the size of 

 the contraction the uterine strip gives :' If you had a 

 standard preparation of pituitary extract could you coin- 

 pare with this the strength of an unknown sample? If one- 

 half as large a dose of the unknown sample were required to 

 give a tracing three inches high, as was required of the 

 standard preparation, what could you say of the relative 

 strengths of the two samples? How much would you dilute 

 the unknown preparation to bring it to the same strength 

 as the standard? This is essentially the method commonly 

 used to standardize (assay) pituitary preparations for the 

 market. (For literature, see Dale and Laidlaw: Journal 

 of Physiology, 1910-11, xli, p. 318; Dale and Dixon: ibid, 

 1909, xxxix, p. 25; Dale and Laidlaw: Journal of Pharma- 

 cology and Experimental Therapeutics, 1912, iv. p. 75: 

 Hamilton, H. C. : Journal American Pharmaceutical Asso- 

 ciation, 1912 ; Roth, G. "\V. : Bulletin Hygiene Laboratory, 

 No. 100; also Journal Pharmacology and Experimental 

 Therapeutics, 1914, v. p. 557; Fenger: Journal Biologic 

 Chemistry, 1916, xxv, p. 417; Frankl-Hochwart und Froh- 

 lich: Archiv fur experimentelle Pathologie und Pharma- 

 kologie, 1910, Ixiii, p. 347 ; Hamilton and Rowe : Journal of 

 Laboratory and Clinical Medicine, 1916, ii, p. 120.) 



