Ultrastructural immunocytochemical localization of lysozyme in the mucociliary epithelium of the rabbit endocervix in different hormonal states

Reproductive Tract Infections in Horses

Diagnosis, treatment, and, ultimately, prevention of reproductive disease are vital components of equine veterinary medicine. A thorough understanding of anatomy and physiology is necessary to reconcile the pathologic findings of disease. Only then can a rational treatment plan be formulated. Many recent advances in knowledge about the reproductive system of multiple species have application to the mare and stallion.

Postnatal development of the cervical epithelium in the Mongolian gerbil

This study analyzes the postnatal development of the Mongolian gerbil's cervical epithelium, in relation to its future functions. In the newborn gerbil the outline of the cervical canal is smooth, showing hardly any signs of folding. The epithelium consists of 1 to 3 layers. The cervical cells have rounded apices of regular outline and contain a large amount of glycogen. The first secretory products of specific mucus type appear about day 23 postnatally (p.n.). Initially two types of vesicles can be identified, as compared with only one type in sexually mature animals. The process of mucification begins in the vagina and the external os of the cervix and spreads towards the cervical horns. The cervical canal, besides growing longer, becomes increasingly folded during development. At about day 50 p.n., with the onset of sexual maturity, an upper endocervix and a lower ectocervix can be distinguished within the cervical canal. In the fully mature animal, the endocervix consists of 4 to 5 layers, in which apical cells mucify and exfoliate. In the ectocervix, the epithelium can be divided into 4 to 5 basal layers and 5 to 7 upper layers which mucify, keratinize, and exfoliate, according to the cyclic phases of the vagina. Diapedesis of leucocytes through the epithelium starts around day 45 p.n.

Light and electron microscopic observations on the cervical epithelium of the rabbit: II

The endocervical epithelium of long-term ovariectomized rabbits treated for 1-10 days with 5 micrograms of estradiol benzoate every 12 hr has been studied by light and electron microscopy. In addition, morphometric data on ciliated and nonciliated cells of rabbits treated for 2, 6, and 10 days are compared to those on untreated ovariectomized, estrous, and ovulatory rabbits. The percentage of ciliated cells increases after ovariectomy to 76.3% and that of secretory cells decreases to 23.7% as compared to estrous controls. Treatment of ovariectomized rabbits with estradiol results in a gradual increase in ciliated and secretory cell area, height, and nuclear area. After 10 days of treatment, cell areas are significantly larger than those in the ovulatory or estrous controls; cell height and nuclear areas have returned to preovariectomized levels; and the percentages of ciliated and secretory cells have reached those of estrous levels. Estradiol stimulates mitotic division of secretory cells but affects ciliogenesis minimally. In ciliated cells, estradiol treatment results in a modest increase in polysomes and granular endoplasmic reticulum and in striking increases in the size of the Golgi complex and in the number of lipofuscin bodies as compared to those in the ovariectomized controls. In secretory cells, estradiol treatment brings about an increase in the numbers of polysomes, Golgi complexes, and cisternae of the granular endoplasmic reticulum, in the sizes of the nucleoli, and in the amount of euchromatin. Secretory granules appear in some cells after 2 days of estradiol stimulation and increase in number through 10 days of treatment. Perinuclear granules are more pleomorphic and heterogeneous in structure and more numerous in the 6- to 10-day-estradiol-treated than in ovulatory animals, and they may function as lysosomes degrading excess secretory product. Deep apical concavities of the secretory cells occur most often after 2 and 6 days of treatment.

Light and electron microscopic observation on the cervical epithelium of the rabbit. I

The light and electron microscopy of the cervical epithelium of ovulatory, estrous, and long-term ovariectomized rabbits have been studied to determine what structural changes occur under different hormonal conditions. The percentage of nonciliated secretory cells is 49.6 in ovulatory, 43.6 in estrous, and 23.7 in long-term ovariectomized rabbits, and of ciliated cells is 50.2 in ovulatory, 56.2 in estrous, and 76.3 in long-term ovariectomized animals. The values for the ovulatory and estrous rabbits are significantly different at the P less than 0.05 level from those of the ovariectomized animals. In all 3 groups the general ultrastructure of the normal ciliated cells is similar. Interestingly, the Golgi complex is very prominent in all. Glycogen bodies occur frequently only in ciliated cells of ovariectomized and occasionally of estrous animals. Abnormalities in ciliation are quite common in the ovariectomized rabbits. The structure of the nonciliated secretory cells varies appreciably within and between the 3 groups. In these cells from well-developed epithelia of certain ovulatory and estrous animals, the apical cytoplasm contains secretory granules of at least three types. In addition, very irregularly shaped, dense, perinuclear granules occur, which may be another type of secretory granule or lysosomes. As compared to ciliated cells, the secretory cells have less prominent Golgi complexes, more abundant bundles of intermediate filaments, a more extensive glycocalyx on their apical surface, and more heterochromatic nuclei. In comparison to the cells of well-developed epithelia, the nonciliated cells of some other ovulatory and estrous rabbits are less well differentiated with fewer or no secretory granules and less well developed organelles. In the nonciliated cells of the long-term ovariectomized rabbits, there are no secretory or dense perinuclear granules. There is a decrease in the number of organelles that are involved in secretion, in the size of the cells, and in the amount of nuclear euchromatin.

Normal distribution of lysozyme- and lactoferrin-secreting cells in the chinchilla tubotympanum

The distribution of the antibacterial enzyme lysozyme- and lactoferrin-secreting cells in the tubotympanum of normal chinchillas was studied using an immunohistochemical technique. The middle ear mucosa contained lysozyme-secreting cells and lactoferrin-secreting cells. The former were localized primarily in the columnar epithelium area and the latter primarily in the cuboidal epithelium area (that contains serous cells) of the transitional zone. In the eustachian tube, the lysozyme was localized in goblet cells of the mucosal epithelium and mucous cells of the glands, while lactoferrin was localized in serous cells of the glands. Our results indicate that secretory lysozyme and lactoferrin are secreted by different cell types (mucous or serous), supporting the notion of heterogeneity of the secretory cells of the tubotympanum. This finding is consistent with the concept that antibacterial enzyme secretion is an integral part of the normal mucosal defense system in the tubotympanum.

Enrichment of lysozyme-containing cells from the rabbit endocervix by unit gravity sedimentation

Lysozyme is a bacteriolytic enzyme component of the secretory granules of endocervical mucous cells. In order to study the subcellular distribution of this enzyme in specific cell populations, endocervical cells from estrous and 5-day pseudopregnant rabbits were separated by unit gravity sedimentation. The application of this technique to pronase-dispersed endocervical cells from estrous rabbits resulted in the isolation and enrichment of two mucous cell types that were distinguished morphologically into type I and type II cell populations. Lysozyme was identified in both cell types, using an unlabeled antibody enzyme method, and the degree of staining paralleled the number of mucous granules. In the absence of estrogen dominance in 5-day pseudopregnant rabbits, there was a 50% reduction in the number of mucous cells with a concomitant reduction in both the number of secretory granules per cell and the intracellular concentration of lysozyme. In the absence of ovarian steroid hormones, i.e., 15-16 weeks after ovariectomy, endocervical cells were devoid of secretory granules and lysozyme staining was negative. Enriched populations of endocervical cells represent a potential experimental model for studying the hormonal role in the regulation of lysozyme synthesis by specific cell populations.