THE PROSTATE GLAND AS AN ENDOCRIN ORGAN 533 



Effect of Prostatectomy on the Neuro muscular Efficiency of Rats. 



The author in collaboration with J. L. Ulrich (1921) has undertaken an 

 investigation to determine the effect of prostatectomy on the neuromuscu- 

 lar efficiency of rats. This investigation is still in progress but sufficient 

 data have already been accumulated to warrant certain tentative conclu- 

 sions. White rats were trained to run over a tightly stretched rope. This 

 is a rather difficult trick to learn but after repeated trials the animals can 

 run over the rope from one end of a room to the other without slipping 

 and at a very rapid gait. This performance requires a very accurate co- 

 ordination of the limbs and indeed of all the muscles of the body, as can 

 be noted by comparing trained rats with untrained ones. Two series of 

 experiments were made: In one series fully developed adult rats were 

 first trained to run on the rope and after they were perfectly accomplished 

 in this respect their prostate glands were completely extirpated. After 

 recovery from the operation the rats were retrained again and after a few 

 trials ran over the rope equally as well as before the operation. In a 

 second series a number of young rats were first prostatectomized and after 

 recovery from the operation the authors began to train them on the rope. 

 It was found that these rats could not learn the rope problem even after 

 a great many trials, whereas non-prostatectomized normal rats learned the 

 rope problem after a definite period of time. Prostatectomized animals 

 showed a distinct weakness of the muscles, especially those of the hind 

 limbs. This was not due to the operative technique inasmuch as other 

 rats on which laparotomy was performed, when, for instance, the testes 

 were excised, did not show such muscular incoordination and weakness. 



The authors then undertook to feed the prostatectomized rats on cer- 

 tain glandular tissues and the results obtained after feeding seemed to 

 show an improvement of their condition. These latter experiments, how- 

 ever, are still in progress and will not be described in detail in this place. 



Summary 



An examination of all the data concerning the prostate described above 

 reveals on the one hand certain negative results and on the other some 

 data which speak in favor of an internal secretion of that gland. It 

 will be noted that no relationship between a prostatic hormone and the 

 tonicity and contractions of the bladder and other genito-urinary organs 

 could be found. Again, it will be seen that the thromboplastic properties 

 of prostatic extracts are attributable to the presence of cephalin in that 

 gland and are not specific for that organ. Lastly, the experiments on 

 the rats in the circular maze seem to indicate pretty conclusively that 

 the extirpation of the prostate gland bears little or no relation to the 

 behavior of the animals. 



