The influence of thyroid and testicular hormones on globule leucocytes in the rat duodenal crypt epithelium

Developmental changes in intestinal globule leukocytes of normal rats

The changes in the number, distribution, and ultrastructure of globule leukocytes (GL) during postnatal development were investigated in the intestinal epithelium of non-infected healthy rats. Intestinal GL were abundant in normal newborn rats even in the absence of infection. They subsequently decreased markedly to the adult level by the fourth week. Ultrastructurally, morphological variations suggesting maturation of the cells were observed in the GL during development. These changes could be noted neither in the mucosal mast cells (MMC) nor in the granular intra-epithelial lymphocytes. Morphological differences between GL and other cells were evident in adult animals. Most notably, paracrystalline structures were found exclusively in the granules of the GL. Immunohistochemically, both the GL and MMC were stained with anti-serotonin, but not with anti-IgE. Degranulation of GL in developing rats was caused by repeated intraperitoneal administration of dexamethasone. Neither GL nor MMC were affected by compound 48/80. These results indicate that (1) the GL and MMC are derived from a common ancestral cell toward the end of embryonic development, (2) the immature GL migrate from the lamina propria into the epithelium to differentiate, mature, and proliferate, and (3) the immature GL have specific functions during the neonatal period.

Selectivity, specificity and kinetics of the androgen regulation of the ocular secretory immune system

The purpose of the present investigation was to determine the selectivity, specificity and kinetics of the androgen regulation of the ocular secretory immune system. To examine the mucosal selectivity of hormone action, tears, saliva, respiratory and intestinal secretions, urine and serum were collected from orchiectomized rats following four days of treatment with saline or testosterone. Androgen administration significantly increased the tear levels of IgA and free SC. In contrast, this combined hormone response was not duplicated in other mucosal secretions or serum. Consequently, it appears that the androgen control of the ocular secretory immune system is unique to the eye. To evaluate androgenic specificity, orchiectomized rats were treated for four days with saline, testosterone, 5 alpha-androstan-17 beta-o1 ('5 alpha'), 4-estren-7 alpha-methyl-17 beta-o1-3-one ('4-E') or the synthetic analogue, danazol. Results demonstrated that testosterone and '4-E', a potent androgen, both stimulated the accumulation of tear IgA and free SC, compared to amounts in tears of saline-treated controls. The weak androgen '5 alpha' induced a slight rise in tear free SC, but not IgA, levels, whereas danazol had no effect on the ocular secretory immune system. These findings indicate that androgen structure is of critical importance in modulation of mucosal immunity in the eye. Lastly, to assess the kinetics of hormone action on tear IgA and free SC, orchiectomized rats were acutely (0, 1.5, 4, 7, 12, or 24 hours) or chronically (0, 4, 7, 11, 14, or 17 days) exposed to testosterone. Acute androgen exposure for less than 12 hours did not elicit any change in the tear content of IgA or free SC. In comparison, chronic androgen treatment induced a progressive and dramatic rise in the levels of both tear proteins. By 17 days of hormone exposure, the IgA and free SC concentrations in tears had increased by 14- and 18-fold amounts, respectively, relative to amounts in placebo-treated controls. Of interest, the temporal pattern of accumulation of tear IgA and free SC were different. Overall, these results show prolonged, but not abbreviated, exposure to androgens has a profound impact on the IgA and free SC profile in tears.

Globule leukocytes in the respiratory epithelium of human upper airways: an ultrastructural study

The ultrastructure of globule leukocytes is described in the nasal and tracheal respiratory epithelium of three boys suffering from chronic airway infections. The globule leukocytes lie free in the intercellular spaces and appear to be migratory cells. They are characterized by intracytoplasmic membrane-bound globules, variable in number, size, shape, and internal structure. The globules may apparently release their content between the neighboring epithelial cells. Human globule leukocytes are also characterized by the presence of intracytoplasmic rod-shaped bodies, the significance of which is not known. They usually display an extended juxta-nuclear Golgi apparatus, presumably involved in the formation of the globules. Comparison of the fine structure of the globules in the globule leukocytes with that of the granules found in the subepithelial mast cells does not support a mast cell origin for human globule leukocytes. On morphological grounds, natural killer cells are postulated as a possible source for globule leukocytes. The function of globule leukocytes is briefly discussed. We presume that the globule leukocytes belong to the group of migrating and secreting cells involved in the defense of the organism against foreign material.