Purpose: To investigate the presence and distribution patterns of hormone receptors in the lacrimal drainage system in normal and diseased states.
Methods: The study was performed on cadaveric and clinical samples of the lacrimal drainage system. Immunohistochemical labeling was performed for assessing the presence and distribution of receptors of estrogen alpha, estrogen beta, aromatase (CYP19), testosterone, progesterone, oxytocin, prolactin, and somatostatins 1 to 5 (SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5). The immunohistochemistry stains were scored as positive or negative, and the distribution patterns in the canaliculus, lacrimal sac, and nasolacrimal duct were assessed.
Results: There was a strong expression of estrogen alpha, estrogen beta, and oxytocin, but this showed variations in distribution patterns. Testosterone and progesterone expressions were more localized to the basement membrane of the epithelium in postmenopausal females. While SSTR2 and SSTR4 expressed only on the villus surfaces of superficial epithelial cells; oxytocin, aromatase, and prolactin additionally expressed in the subepithelial lamina propria and submucosal glands. Diseased samples from primary acquired nasolacrimal duct obstruction showed dramatic reduction or absence of the receptor expression patterns of all the hormones with the exception of epithelial immunoreactivity with prolactin.
Conclusions: This study provides a proof of principle for the presence of multiple hormone receptors and hypothesizes their possible links in the etiopathogenesis of primary acquired nasolacrimal duct obstructions.