194 
Journal of Agricultural Research voi. xxvm, No. 2 
The other investigators reported a low digestibility of the protein in cottonseed 
as measured by fecal nitrogen. The smallness of the increase found in the present 
investigation may be due to the manner of administering the gossypol. Perhaps 
it did not come in close enough contact with the meat protein of the cat’s food. 
Moreover, the experiments herein reported were conducted so that absorption 
was favored by cutting the diet down to a low level and by checking the tendency 
to diarrhea with bone ash. In an experiment conducted without bone ash and 
with a large dose of gossypol the diarrhea was marked and the fecal nitrogen was 
high. 
PARALYSIS FROM GOSSYPOL 
When the gossypol content of the rabbits’ diet was adjusted to between 225 
and 450 parts per million, two of the rabbits which retained a fairly good appetite 
developed spastic paralysis of the hind legs within two months. The hind legs 
were stiff and protruded forward upon the abdomen (similar to cat shown in 
PL 2, B). The anogenital region became edematous and ulcerated and there was 
dribbling of urine. Paralysis also occftrs in cats (PI. 1 and 2), the hind legs being 
more often affected. In several cases in which only the fore legs seemed to be 
affected there was reason to suspect that the hind legs were also involved, although 
not enough to be apparent. The paralytic condition may become progressively 
worse for a time after the gossypol diet is discontinued or may improve while 
the gossypol diet is being continued. The kangaroo hop (PL 2, C and D) illus¬ 
trates the effort of the animal to compensate for the paretic condition. Even the 
tail is brought into play as an accessory organ of locomotion. 
Paralysis was observed not only in rabbits continuously fed gossypol but also 
in one rabbit which survived intraperitoneal injection of 5 mgm. of gossypol per 
kilo dissolved in peanut oil, and in one receiving orally 50 mgm. of gossypol per 
kilo dissolved in peanut oil. Only these two individuals out of a large number of 
rabbits which were injected showed paralysis. The paralysis developed within 
10 to 20 days, being preceded only by weakness. Within several more days the 
hind legs became spastic and extended. The hind legs were affected unequally. 
The inequality was especially well shown in the behavior of the tail, which turned 
to one side. Almost complete recovery occurred within two months. 
Although on injecting other animals the paralysis could not be reproduced, 
it is believed that the paralysis of the two rabbits described was due to gossypol, 
for among the several thousand rabbits observed in the pharmacological 
laboratory of this Bureau spontaneous paralysis has never been encountered. 
Moreover, the paralysis resembled exactly that found on feeding gossypol. It 
is believed that these observations on the feeding or injection of gossypol are 
the first recorded instances of a paralysis in rabbits which is attributable to 
gossypol or to* cottonseed products. 
Gossypol has a paralytic effect not merely upon the neuromuscular apparatus 
of striated muscle but also upon that of smooth muscle. At any rate it produces 
definite paralysis of the isolated rabbit intestines in concentration of about 1 to 
5,000 within about 15 minutes. With more dilute solutions, such as 1 to 100,000, 
he effect was not so certain. Post-mortem examination of rats dead of intra¬ 
peritoneal injection of gossypol frequently reveals a condition resembling para¬ 
lytic ileus. As cottonroot bark which contains gossypol is-regarded as an aborti- 
facient, some effect upon the smooth muscle of the uterus might be anticipated. 
However, while no experiments were made upon the isolated uterus, abortion 
could not be effected in pregnant cats or rabbits by poisoning them with gossypol. 
The few fetuses which were born succumbed and presumably would have been 
born anyway. In one case only part of the litter was born. When pregnant 
animals poisoned by gossypol were sacrificed, live fetuses were found and no 
separation of placentae was observed. 
