Serous cysts of the aging guinea pig ovary. II. Scanning and transmission electron microscopy

Updates on Cystic Ovarian Disease in Guinea Pigs

Cystic ovarian disease is the most common reproductive tract disorder in female guinea pigs, and concurrent uterine pathology may also be present. Nonspecific clinical signs include decreased appetite, lethargy, hunched posture, weight gain, palpable mass(es) in the midabdomen, and progressive abdominal distension. Additionally, bilateral, nonpruritic alopecia of the flank and ventral abdomen; hyperkeratosis, crusting, and/or hyperpigmentation of nipples; clitoral hypertrophy; reduced fertility; and behavioral changes may also be appreciated. Confirmation of disease is most often made with abdominal ultrasound but may also occur during exploratory abdominal surgery. Recommended treatment is surgical management with ovariohysterectomy or ovariectomy.

Ovarian cysts in the guinea pig (Cavia porcellus)

This article reviews ovarian cysts in the guinea pig (Cavia porcellus), a disease commonly associated with symmetric, nonpruritic alopecia of the dorsum and flanks. Relevant anatomy is discussed and current theories of pathogenesis are reviewed. Prevalence, predisposing factors, diagnosis, treatment, and prognosis are presented.

Ovarian Cysts in MRL/MpJ Mice Originate from Rete Ovarii

In MRL mice aged more than 1 year, but not in C57BL/6 mice, ovaries had grossly visible cysts presenting unilaterally or bilaterally. Postnatally, all MRL mice developed ovarian cysts by 8 months of age. Observations by light microscopy, including lectin histochemistry, indicated that the cysts sometimes included papillomatous tissues located at the hilar region and were similar to the rete ovarii system, but not to follicles. Two types of epithelial cells, ciliated and non-ciliated, were arranged on the cysts, in which both cell types had many microvilli projecting in various directions and random ramifications in the cystic lumen. These characteristics suggest that ovarian cysts developing in MRL mice originate mostly from the rete ovarii. Cysts derived from the rete ovarii at 8 months of age were histologically detected in all C3H mice as well as MRL mice, with variable incidence in ICR, AKR, CBA/N and ddY, and none in C57L/6, DBA/2, BALB and A/J mice. However, measurement of the maximum diameters of the ovarian cysts indicated that MRL mice regularly possessed the largest cysts visible to the naked eye. This is the first report of ovarian cysts in this inbred strain, suggesting that ovarian cysts in MRL mice appear with stable incidence and development.

Intraperitoneal serous adenocarcinoma: a critical appraisal of three hypotheses on its cause

OBJECTIVE

Serous ovarian, Fallopian tube, and peritoneal adenocarcinomas are remarkably similar, both in their morphology, as well as in their clinical behavior. Despite extensive clinical and fundamental research, controversy still exists on the origin of serous female adnexal tumors. Difficulties in identification of site of origin at late stage the of disease at detection, when ovary, Fallopian tube, and the abdominal cavity are usually all involved, in addition to their macroscopic and microscopic resemblance, are major causes of this debate. In 3 hypotheses, 3 possible tissues of origin are proposed: the ovarian surface epithelium, the Fallopian tube epithelium, and the secondary Mullerian system.

STUDY DESIGN

We searched for all peer-reviewed articles and reviews that examined "serous ovarian carcinoma," "Fallopian tube carcinoma," "Mullerian system," "ovarian surface epithelium," "tubal epithelium," and "peritoneal." We included only articles that could give information on the origin of serous carcinomas. Additional articles were added by examining references of overview articles in relevant fields.

RESULTS

Discussed are the experimental data underlying these hypotheses.

CONCLUSION

An attempt is made to integrate the 3 hypotheses into a comprehensive model of serous intraperitoneal adenocarcinogenesis. It can be concluded that the Fallopian tubes play a major role in the development of female serous cancer.

Ovarian cysts in guinea pigs: influence of age and reproductive status on prevalence and size

Forty-three guinea pigs presented as part of a screening programme were divided into six categories on the basis of age and reproductive history. Three age groupings were used: less than one year, one to two years, and over two years. Each age group was further divided into two categories: animals which had had single or multiple pregnancies, and animals which had never bred. Each animal received a clinical examination and was scanned using B-mode ultrasound for the presence of ovarian cysts. Possible relationships between reproductive history and the prevalence of cysts were investigated using Mantel-Haenzel analysis, and between prevalence, cyst size and age using linear regression analysis. Two out of the 43 animals (4.7 per cent) showed symmetrical alopecia. No statistically significant correlation between reproductive history and the prevalence of cysts was detected at the 95 per cent confidence level. A statistically significant relationship was found, however, between cyst size and age (P<0.01) and between cyst prevalence and age (P<0.02).

Observations on the solitary cilium of rabbit oviductal epithelium: its motility and ultrastructure

Solitary cilia have been observed on rabbit oviductal epithelial cells. In tissue cultures of fimbrial epithelium of 3- and 4-day-old animals observed by phase microscopy, most of these single cilia exhibited a vortical or funnel-type movement while others had the usual to-and-fro motility. Primary cilia are usually considered immotile. Transmission electron microscopy of specifically identified single cilia revealed differences between the ciliary shafts and basal bodies of the single cilia as compared to those of mature oviductal ciliated cells. The basal body of the solitary cilium often had at least two triangular, striated, basal foot processes, lacked electron-dense satellite material around its basal end, and occasionally had striated rootlets. In contrast, the cilia of mature ciliated cells had only one basal foot, exhibited much electron-dense satellite material, and lacked rootlets. Cross sections of the single cilia showed patterns of microtubules different from the usual 9 + 2 axonemal complexes of normal cilia and included 9 + 0, 10 + 2 singlets, 7 + 2 doublets, and 8 + 1 doublet and 2 singlets; one did have the usual 9 + 2 arrangement. We postulate that the presence of more than one basal foot process may be responsible for the vortical motility observed. The primary cilia are shorter than normal cilia; the longest one measured was 1.86 micron in length, 0.28 micron in width at its base, and 0.14 micron at its tip. Based on the light-microscopic, scanning-electron-microscopic and transmission-electron-microscopic observations, such solitary cilia were observed more frequently in the oviductal tissues of the 3- to 4-day postnatal rabbits grown in tissue culture and in ovariectomized and ovariectomized/progesterone-treated adult animals than in estrous, ovulatory, or ovariectomized/estradiol-treated rabbits.

Serous cysts of the aging guinea pig ovary. III. Permeability of the cyst epithelium to lanthanum and horseradish peroxidase

The permeability of the epithelium lining serous cysts of the guinea pig ovary was examined using lanthanum and horseradish peroxidase (HRP). Both lanthanum and HRP introduced at the luminal surface of the cyst penetrated to the basal region filling caveolae in both lateral and basal cell surfaces. Within three minutes of vascular infusion of HRP, the tracer was detected between epithelial cells and in caveolae on their lateral and basal surfaces but not associated with intracellular organelles. There was no change in the intracellular distribution of HRP after ten minutes. It was concluded that the epithelium was permeable to the tracers within this time period but that pinocytosis and transport of these tracers through the epithelial cell were not demonstrated.

Pattern of follicular growth and steroidogenesis in the ovary of aging cycling rats

Prior to the cessation of reproductive cycles, older female rats exhibit irregular and prolonged cycles due to alterations in the hypothalamic-pituitary-ovarian axis. In order to evaluate the age-related changes in the ovary, the histology, and estradiol, testosterone and progesterone concentrations within the ovaries of mature regular cycling (4--5 mo. old) and older irregular cycling (10--11 mo. old) rats were examined. At estrus, the number of non-atretic growing follicles (150--300u in diameter) was greater in the mature than in the older rats (18 +/- 1.5 vs 4.5 +/- 1.4). However, the number of preovulatory follicles on proestrus did not differ (6.0 +/- 1.2 vs 5.5 +/- 0.6). Estradiol, testosterone and progesterone concentrations on proestrus in mature rats averaged 38.8 pg, 56.1 pg, and 1.0 ng/ml of ovary, respectively. In the older proestrous rat, only estradiol was altered, increasing to 124.3 pg/mg. In addition, many of the preovulatory follicles within the aged ovary were larger (greater than 600u in diameter) than those within the mature ovary. On the day of estrus virtually all preovulatory follicles ovulated in the mature rat, whereas large follicles, less than or equal to 600u in diameter, remained in the older ovary. In addition, estradiol levels remained elevated and ovarian cysts were observed in the aged ovary. Thus, in the older irregular cycling rat, 1) pre-ovulatory follicles develop, but many do not ovulate; 2) these non-ovulatory follicles form ovarian cysts which remain within the ovary. The number of cysts may increase with age until a polycystic ovary develops and the rat enters a constant estrous state.