A study on the Distribution of Immunoreactive Atrial Natriuretic Peptide in Rat Eye

Atrial natriuretic peptide(ANP) is a 28-amino acid hormone with potent natriuretic effect and diuretic one. ANP wag originally thought to be involved in the regulation of blood pressure and blood volume. However, recent studies have indicated that ANP has much wider physiologic roles, such as the regulation of mitoses, the secretion of thyroglobulin, the production of cerebrospinal fluid and aqueous fluid formation. This peptide hag been detected in the anterior uvea, retina and corneal endothelium. It was reported that ANP decreased intraocular pressure and aqueous humor formation. However the distribution of ANP in the eye was not clearly confirmed. This study was carried out to localize the immunoreactive ANP in the rat eye. The distribution of alpha-ANP in the rat eye was studied by immunohistochemistry using a polychnal antibody against synthetic rat alpha-ANP. Immunoreactive ANP was localized intensely in the epithelium of the ciliary body. ANP immunoreactivity was also strong in the corneal endothelium, iris and in the anterior epithelium of the lens. The immunoreactivity was observed in the nerve fiber layer, ganglion cell layer and inner plexiform layer in the retina. These data clearly confirm that ANP is widerly distributed and that it takes part in diverse functions in the rat eye.

Effect of Corticosteroid on Orbital Pseudotumor Caused by Orbital Myositis

Idiopathic orbital myositis, a subgroup of inflammatory orbital pseudotumor may occur with acute-onset periorbital pain, diplopia, and, in most cases, eyelid swelling. Proptosis, extraocular muscle motility restrictions, and response to oral prednisolone administration were characteristic. Although the CT appearance of orbital myositis is often helpful, the findings are not pathognomonic: correlation with history, clinical finding, and therapeutic response must be considered in making the diagnosis. The results of corticosteroid therapy on the orbital pseudotumor caused by orbital myositis were as follows: 1. The effect of corticosteroid was more effective in single extraocular muscle involvement than in that of a multiple extraocular muscle. 2. Early age of onset and early treatment after symptom increased the effectiveness of corticosteroid therapy.