In a previous report, authors reported clinical findings of reproductive disorders which were caused in bulls by subcutaneous injection with diethyl-stilbestrol (DES).
The present report deals with the histopathological findings of testis of bulls when the semen quality became poor described in the previous report. Testicular specimens for histopathological examinations were harvested by means of biopsy. However, testicular biopsy specimens were unable to be harvested repeatedly so many times that supplemental examinations were carried out by use of male rats which were given DES to get more precise data of the effect of DES on bulls.
As described in the previous report, No. 1 bull received daily injections with 5 mg DES for 30 days. Testicular biopsy specimen was taken out next day after the last injection. Additional daily injections with 10 mg of DES started on the 33 rd day after harvesting tessticular biopsy specimen and continued for two weeks. The specimen was taken again 25 days after the last injection. No. 2 bull received a daily injections with 5 mg of DES for 35 days and then testicular biopsy specimen was taken out 9 days after the last injection. No. 3 bull recived a daily injection of 2. 5 mg of DES for 110 days, and then testicular biopsy specimens were taken out twice; 9 days and 35 days after the last injection.
Rats, 7-8-week-old, were divided into two groups by the difference of the period of subcutaneous injection with DES : for 10 days and for 20 days. Each group was divided into 5 subgroups by a daily dose of DES injected. Each subgroup consisted of each 5 rats, daily dose of DES were 0. 02 γ/0.1m
l in No. 1 subgroups, 0.2 γ/0.1 m
l in No. 2, 2 r/0.1 m
l in No. 3, 20 γ/0.1 m
l in No. 4, 200 γ/0.1 m
l in No. 5. In addition, a group which received no injection of DES was placed as control.
Testis were harvested from the rats of each group next day and 10 days after the last injection, The materials harvested were fixed in Bouin's solution and the sections were stained by H-E, Azan, . and Van Gieson stains. The results obtained are as follows:
1) In bulls tested, some of tubules showed atrophic degeneration. In most of tubules, many pres-permatids, some of spermatocytes and a few of Sertoli cells were sloughing off from seminiferous. epithelium. Multinucleated giant cells composing of prespermatids and prespermatids showing nucleo-picnosis or nucleohydrops were observed in tubules. In interstitial tissue, edema, enlargement of capi llary blood vessels and looseness of its wall were observed. Leydig cells were normal in number, but some of them showed a little atrophy. Examining interstitium one month after the last injection, a slight increase of intertubular connective tissue was observed.
2) In the rats, the atrophy of testis was observed both the weight of testis and diameter of semi-niferous tubules decreased. The histological findings of testis were severe in the groups of rats inje cted with more than 2. or of DES daily for either 10 days or 20 days. and the changes were just like those of bulls. In the groups of rats injected daily with more than 20 γ, Leydig cells showed atrophy with shrinked nuclei. In the groups of rats administered with a little dose, spermatogenesis was normal except the last stage. Therefor no spermatozoa was found in seminiferous tubules, but Leydig cells were normal or rather active. In cases examined 10 days after the last injection, it was noted that Leyding cells were normal, or increased slightly in their size and number, althogh the damage of germinal epithelium was severe and extensive.
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