Glascock (11), using tritiated hexestrol in lambs and goats, also reported measurable 
amounts of radioactivity in tissues after 24 hours and even after 48 hours. Many tissues 
were examined and accumulation was found in almost all tissues and organs. About 1.5 
percent of the administered activity remained in the body tissues after 24 hours and only 
about 0.8 percent after 48 hours. The use of this very high specific activity achieved by 
tritium labeling has resulted in the first confirmation of selective localization in repro- 
ductive organs, since the uterine endometrium, vagina, myometrium, oviducts, ovaries, 
and mammary glands were found to have higher relative concentrations than other 
tissues and organs. 
There have been numerous studies on the presence of hormone residues in poultry 
tissues. In 1947 Bird, etal. (3) found that when the dimethyl ethers of stilbestrol (dianisyl- 
hexene), hexestrol (dianisylhexane), and dienestrol (dianisylhexadiene) were fed for 7 to 
12 days the abdominal fat contained large quantities of estrogenic activity, 2.5 to 4.3 mg., 
5 mg. and 1.5 mg., respectively, per 100 gm. of adipose tissue. Estrogenic activity was 
found in all the extracts of tissues of the cockerels fed the ethers of the estrogens or 
injected subcutaneously with these compounds. The muscular tissues were low in activity 
but skin, liver, gizzard, and abdominal fat showed high potency. When liver or fat from 
treated birds was fed to postmenopausal women, estrous changes were observed in their 
vaginal smears, indicating the high estrogenic content of the tissues. The above com- 
pounds have not been used commercially. 
Tiger, Mitchell, and Goff (36) in 1956 found no detectable estrogen in extracts of 
skin, muscle, abdominal fat, and liver from chickens fed dienestrol diacetate (32 mg./1lb. 
of feed). In 1959 Umberger and Gass (40) reported results very similar to those obtained 
by Tiger, et al. (36). When dienestrol diacetate was fed at the rate of 32 mg./lb. feed for 
3 weeks and the estrogen feed replaced with a control mash 24 hours before killing, no 
estrogenic residues could be detected in muscle, abdominal fat, skin fat, heart, gizzard, 
or spleen. Estrogenic activity was found in liver (3 p.p.b.), kidney (12 p.p.b.) and small 
intestine (10 p.p.b.). The results suggested that dienestrol diacetate is not stored in the 
edible tissues, but a period of 24 hours off the estrogen feed is not sufficiently long to 
insure complete removal of the estrogen from the usual pathways of excretion. 
Gowe (13) reported estrogenic activity of not more than 14.5 Mg in the extracts of 
100 gm. of muscle and skin and 5 Mg in the extracts of 100 gm. of liver. No activity was 
found in turkey gizzards, hearts, and abdominal fat. In 1950 Colombel (5) reported large 
quantities of estrogen, 6,000 p.p.b. DES equivalents in chicken livers from birds castrated 
chemically with 15 mg. and 30 mg. pellets.of stilbestrol. Meyer (25) determined 13 p.p.b. 
estrone equivalents in extracts of chicken carcass and 24 p.p.b. estrone equivalents in 
extracts of chicken livers after 12 mg. stilbestrol pellet treatment. 
Campbell and Wick (4) in 1952 found no estrogenic activity in extracts of chicken 
carcass but determined 60 to 118 p.p.b. estrone equivalents in chicken livers after 
implantation of 12 mg. stilbestrol pellets. Turkey liver extracts from 12 mg. pellet 
implants also showed 50 p.p.b. estrone equivalents. Greenblatt and Brown (14), however, 
found no estrogenic activity in extracts of chicken fat from chickens treated with 15 mg. 
and 30 mg. pellet implants. Koch and Heim(18) found estrogenic activity in extracts from 
all tissues of chickens treated with 20 mg. stilbestrol pellet implants. Muscle, bones, 
skin, liver, and abdominal fat contained from 0.01 to 34 mg. per 2200 gm. bird. 
Jones and Deatherage (17), using a chemical method for determining stilbestrol, 
failed to detect estrogen in extracts of liver, breast muscle, or abdominal fat. The 
colorimetric method was not sensitive to small quantities of estrogen however, and the 
authors acknowledged the limits of sensitivity in the conclusions in their report. Swift 
in 1954 also used a chemical method for estimation of stilbestrol residues in poultry 
tissues. There was no evidence of estrogen in extracts of breast muscle, leg or back 
muscle but extracts of liver and skin from cockerels treated with a 15 mg. pellet of 
stilbestrol contained 37 Ug./gm. or approximately 0.25 percent of the amount implanted. 
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