A Case of Ovarian Dysplasia and a Vaginal Fibroleiomyoma in a Young Golden Retriever.

This case demonstrates a unique ovarian congenital anomaly that likely contributed to the development of a rare fibroleiomyoma in the cranial vagina of a young bitch. A 13 month old intact female Golden Retriever presented to the veterinary teaching hospital for urinary incontinence, hematuria, and persistent vaginal discharge. Physical examination revealed a mucopurulent serosanguinous malodorous vulvar discharge, and after further diagnostics was reclassified as persistent estrus. Abdominal palpation and ultrasound revealed uterine thickening and poorly visualized ovaries. The reproductive tract was removed during an ovariohysterectomy, revealing small ovaries and a white anterior vaginal mass. Histopathology revealed dysplastic ovaries with hyperplastic granulosa cells and a benign vaginal fibroleiomyoma. These morphologic changes are consistent with elevated estrogen levels. It was thus concluded that her persistent estrus and the fibroleiomyoma were both secondary to persistent estrogen production by the hyperplastic granulosa cells.

Ki-67 antigen expression in the mammary epithelium of female rats in persistent estrus treated with anastrozole.

OBJECTIVES: To evaluate Ki-67 antigen expression in mammary epithelium of female rats in persistent estrus treated with anastrozole. MATERIALS AND METHODS: Twenty-eight Wistar-Hanover female rats in persistent estrus induced by subcutaneous injection of 1.25 mg of testosterone propionate in the second day of life were randomly divided into two groups, control and experimental, with 14 animals each. The animals of control group received only the vehicle (propyleneglycol) and the animals of group experimental received 0.125 mg daily of anastrozole by gavage during 28 days. After 28 days of treatment, all animals were sacrificed and the first pair of abdominal-inguinal mammary glands was removed and fixed in 10% buffered formalin to investigate Ki-67 antigen expression by immunohistochemistry. RESULTS: The mean percentage of Ki-67-stained nuclei per 500 cells in the mammary epithelium was 76.97 ± 0.76 and 14.44 ± 2.02 [mean ± standard error of the mean (SEM)] in the control and experimental groups, respectively (p < 0.0001). CONCLUSIONS: Anastrozole treatment significantly reduced Ki-67 expression in the mammary epithelium of rats in persistent estrus.

Enhancement of Uterine Cancer Development after Oocyte Depletion by Juvenile Exposure to Gamma Radiation in Rats: - A Comparative Study on Sensitivity of Damage to Female Reproductive Organs by Radiation between Juvenile and Adulthood Using a Rat Model.

To clarify sensitivities of juvenile exposure to radiation on uterine carcinogenesis, female Donryu rats, a high yield strain of uterine corpus cancer, were exposed to 0.2 and 1.0 Gy of gamma radiation at postnatal day 14. Sequential changes in their reproductive organs and hematology, and the effects on uterine tumor development were compared to those in adult rats exposed to the same doses. Half number of the rats in each group was treated with N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) after the radiation to accelerate the development of uterine cancer. Severe apoptosis and depletion of oocytes in the primordial/primary follicles were immediately induced after juvenile exposure at 1.0 Gy only. The ovaries in rats exposed to 1.0 Gy at juvenile showed severe atrophy characterized by the loss of all types of follicles and a lack of corpora lutea by 2 months of age, and all rats elicited an early onset of persistent estrus corresponding to the atrophy. At the termination of 9 months of age, juvenile 1.0 Gy exposure with ENNG treatment increased the incidence of endometrial adenocarcinoma and the multiplicities of combined endometrial adenocarcinomas and their precancerous lesions. Enhancement of uterine cancer development was not apparent at the same exposure without ENNG. In comet assays, neither 0.2 nor 1.0 Gy juvenile exposure induced direct DNA damage to uteri though the damage was found in the ovary at 1.0 Gy. The present results indicated that juvenile exposure to gamma radiation indirectly enhanced uterine cancer development in rats through direct damage to oocytes resulting in serious atrophy of the ovary accompanying early onset of persistent estrus. The damage to ovary was more sensitive at juvenile than adults. The result in comet assay suggested that direct DNA damage to the uterus by radiation was excluded.

Effect of a gel containing pilocarpine on vaginal atrophy in castrated rats

OBJECTIVES: To evaluate the effect of Carbopol gel formulations containing pilocarpine on the morphology and morphometry of the vaginal epithelium of castrated rats. METHODS: Thirty-one female Wistar-Hannover rats were randomly divided into four groups: the control Groups I (n=7, rats in persistent estrus; positive controls) and II (n=7, castrated rats, negative controls) and the experimental Groups, III (n=8) and IV (n=9). Persistent estrus (Group I) was achieved with a subcutaneous injection of testosterone propionate on the second postnatal day. At 90 days postnatal, rats in Groups II, III and IV were castrated and treated vaginally for 14 days with Carbopol gel (vehicle alone) or Carbopol gel containing 5% and 15% pilocarpine, respectively. Next, all of the animals were euthanized and their vaginas were removed for histological evaluation. A non-parametric test with a weighted linear regression model was used for data analysis (p<0.05). RESULTS: The morphological evaluation showed maturation of the vaginal epithelium with keratinization in Group I, whereas signs of vaginal atrophy were present in the rats of the other groups. Morphometric examinations showed mean thickness values of the vaginal epithelium of 195.10±12.23 μm, 30.90±1.14 μm, 28.16±2.98 μm and 29.84±2.30 μm in Groups I, II, III and IV, respectively, with statistically significant differences between Group I and the other three groups (p<0.0001) and no differences between Groups II, III and IV (p=0.0809). CONCLUSION: Topical gel formulations containing pilocarpine had no effect on atrophy of the vaginal epithelium in the castrated female rats.