Chromatographic characterization of vasoactive intestinal polypeptide in guinea pig and rhesus monkey eyes.

Acid extracts of guinea pig and rhesus monkey anterior uvea, choroid and retina contain immunoreactive VIP. By reversed phase high performance liquid chromatography, the immunoreactive material from these ocular tissues elutes at a position similar to synthetic porcine VIP. Only in the guinea pig anterior uvea is a second smaller peak detected. By size exclusion high performance liquid chromatography, the peptide in the monkey anterior uvea, choroid and retina elutes in the identical position as the synthetic porcine VIP standard with an apparent molecular weight of 3450 daltons. We conclude that a single form of VIP, chromatographically similar to the porcine standard, is the predominant form of the peptide in the eye of guinea pig and rhesus monkey.

Immunohistochemical localization of peroxidative enzymes in ocular tissue.

Localization of the peroxidative enzymes catalase and glutathione peroxidase in rabbit ocular tissue was investigated by immunohistochemical methods. We raised antisera to both enzymes in rabbits using commercially available purified enzymes. Immunoreactive catalase and glutathione peroxidase were found in the corneal epithelium and endothelium, the choroid, the inner segment of photoreceptors, and the retinal pigmented epithelium.

Renin in the bovine eye.

Recently, high levels of prorenin were found in human vitreous and subretinal fluid. In this study we attempted to identify and quantitate renin and prorenin in the bovine eye. Both these substances are present in the bovine eye in concentrations that cannot be explained by plasma contamination. Concentrations of total renin, i.e. renin plus prorenin, are highest in the posterior uveal tract [15.4 ng angiotensin (Ang) l/g per h]; in the anterior uveal tract the total renin concentration was 10.1, in plasma 6.3, in vitreous fluid 5.7 and in the retina 5.1 ng Ang l/g per h. Vitreous fluid contains mainly prorenin (99%), whereas the retina, and the anterior and posterior uveal tract contain less prorenin (respectively, 78, 47 and 32%). The absence of renin in vitreous fluid is consistent with the general finding that extrarenal renin synthesis is often associated with the release of mainly or exclusively prorenin into the extracellular fluid. Synthesis of renin and prorenin may take place in the eye.

Distribution and development of substance P immunoreactive axons in the chick cornea and uvea.

A study was made of the distribution of Substance P-immunoreactive fibers in chick cornea and uvea in whole mount preparation, using the indirect immunofluorescence technique. The development of these fibers during embryogenesis was also investigated. SP-fibers were present in all chick eye structures, in the various prenatal and postnatal stages examined. Their distribution was comparable with that observed by other workers in mammals. Transformation of the iris musculature from smooth to striated, during development, is not accompanied by significant changes in SP-ergic innervation.

Neuropeptide Y immunoreactive neurons in the guinea-pig uvea and retina.

Neuropeptide Y (NPY) is a recently discovered, amidated 36 amino acid residue neuropeptide present in many but not all sympathetic noradrenergic neurons. In the guinea-pig eye, NPY immunoreactive fibers were found to have the same distribution as noradrenergic fibers except that there were fewer at the iris dilator, in the cornea, and in the chamber angle. In the anterior uvea, the NPY immunoreactive fibers disappeared after excision of the homolateral superior cervical sympathetic ganglion, whereas in the choroid, many NPY immunoreactive fibers remained, indicating that they originate elsewhere. NPY immunoreactivity thus is not found in all sympathetic adrenergic neurons nor is it found only in such nerve fibers. In the retina, NPY immunoreactive fibers formed a single layer of processes in sublamina 1 of the inner plexiform layer. NPY immunoreactive cell bodies were found in the innermost cell row of the inner nuclear layer. The immunoreactivity was concentrated to the hillock region of these cells.

Fc and complement receptor lymphocytes in the ocular tissues of rabbits immunized intravitreally with ovalbumin.

The numbers of antibody producing cells (PFC) and the percentages of Fc receptor cells (FcR) and complement receptor cells (CRL) in the ocular and lymphoid tissues of rabbits immunized intravitreally with ovalbumin were determined. Antibody-producing cells were detected first in the lymph nodes and then in the uveas and corneas. The uveal tracts contained more than 50% FcR early in the antibody response, but the percentages returned to normal levels during the second postinjection week. An apparent inverse relationship between the numbers of ocular PFC and the percentages of ocular FcR was noted. The percentages of CRL in the spleens and lymph nodes were similar to those reported by other investigators. No obvious correlation between CRL percentages in the ocular tissues and the numbers of PFC was seen. The "T-" or "B-" cell nature of the ocular FcR and their possible functions in regulating ocular immune responses are yet to be determined.

Uveal effusion attending scleritis posterior. A case report with A-scan and B-scan echograms.

A report is given of a patient with exudative ciliochoroidal and retinal detachment associated with posterior scleritis. The history and clinical findings were similar to earlier described cases and initially led to suspicion of a malignant melanoma. Ultrasonic examination performed by combination of standardized A-scan and contact B-scan technique allowed the diagnosis to be established and the regression of this condition to be followed. There was complete recovery after treatment with atrophine and topical steroids.

Mapping, quantitative distribution and origin of substance p- and VIP-containing nerves in the uvea of guinea pig eye.

VIP- and substance P-like immunoreactivities were found in considerable concentrations (VIP: 17.3 +/- 4.8 pmol/g, mean +/- SEM; substance P:11.1 +/- 1.8 pmol/g) in the uveal portion of the guinea pig eye. Immunocytochemistry localised these two regulatory peptides to nerve fibres found principally in a plexus in the iris (substance P) and in an extensive network surrounding the blood vessels of the choroid (VIP). A remarkable anatomical demarcation of the two types of peptide-containing nerves was established by the staining of substance P-containing nerves, which stops at the level of the ciliary body. This uveal area is known to be involved in the ocular responses to nociceptive stimuli. At the ultrastructural level, immunoreactivity for both peptides was localised to distinct subpopulations of p-type nerves, distinguishable by the size of their large dense-cored vesicles. Those immunoreactive for VIP were significantly larger (p less than 0.0005) than those immunoreactive for substance P (95 +/- 7 nm and 82 +/- 9 nm respectively; mean +/- SD). Interruption of the trigeminal pathway produced a remarkable decrease of substance P immunoreactivity in the anterior portion of the uvea (9.1 +/- 1.5 pmol/g, mean +/- SEM, control; 5.3 +/- 1.3 pmol/g, denervated), but not of VIP immunoreactivity in the choroid. Following colchicine treatment, VIP-immunoreactive neuronal cell bodies were localised in the choroid. The separate anatomical localisations and distributions of the two uveal peptides appear to be related to their different origins and functional roles in the response of the eye to noxious stimuli.

Glucocorticoid localization by radioautography in the rabbit eye following systemic administration of 3H-dexamethasone.

Dexamethasone was localized radioautographically in the nuclei of target cells of the rabbit eye following intravenous administration of the labeled steroid. Specifically bound steroid was found in the nuclei of stromal and endothelial cells of the outflow pathway region. This suggests that the glucocorticoid-induced alteration in outflow facility may be mediated by specific effects in these target cells. Nuclear localization was also found in conjunctiva, iridial smooth muscle, choroidal stroma, retina, and sclera, suggesting a physiologic role for glucocorticoids in these tissues as well.

Nuclear translocation of the cytoplasmic glucocorticoid receptor in the iris--ciliary body of the rabbit.

The cytoplasmic glucocorticoid receptor of the iris--ciliary body of the rabbit has been shown to translocate to the cell nucleus within 30 min of an injection of cortisol. Over the next 2 1/2 hr the amount of receptor returns to the control value. The threshold of the loss of receptor from the cytosol was found at 0.04 mg of cortisol per kilogram body weight, with a maximal loss being reached at a cortisol dose of 0.5 mg/kg B.W. The inactive glucocorticoid tetrahydrocortisol and the major sex steroids, dihydrotestosterone, estradiol, and progesterone, had little or no effect on this translocation, indicating the specificity of the cortisol effect. Thus this receptor appears to migrate to the cell nucleus in a manner similar to that found in other steroid-sensitive tissues and is consistent with the accepted mechanism whereby these hormones regulate differential gene expression in the nucleus.

The organization of tissues of the eye by different collagen types.

Bovine cornea, sclera, iris, ciliary body, choroid, zonular fibers, lens capsule, lens nucleus, vitreous body, and retina were investigated for collagen content and type. Cornea, sclera, iris, ciliary body, choroid, lens capsule, and vitreous body contain hydroxyproline, whereas in zonular fibers, lens nucleus, and retina no hydroxyproline was detectable. Preparative isolation of collagen was achieved by digestion of the different eye tissues with pepsin. The pepsin-solubilized collagen was separated by differential salt precipitation into different collagen types. The polyacrylamide gel electrophoresis of the pepsin-solubilized collagens revealed type I collagen in cornea, sclera, iris, ciliary body, and choroid. As well as type I collagen, type III collagen was isolated from cornea, sclera, and uveal tissues. The identification of types I and III collagen was supported by the CNBr-derived peptides of these collagens. Lens capsule collagen consisted mainly of type IV collagen. Zonular fibers contained no hydroxyproline but when examined by polyacrylamide gel electrophoresis, a band migrating in the alpha-position of collagen was observed. Polyacrylamide gel electrophoresis of both the pepsin-solubilized component and the CNBr-derived peptides of vitreous body protein showed no relation to any of the four common collagen types.

Release of prostaglandins in experimental immunecomplex endophthalmitis and phacoallergic uveitis.

Prostaglandins-E were demonstrated in the aqueous humour, the anterior uvea, and the choroid of rabbits in which type III allergic reactions were produced by two different methods. In general the levels of prostaglandins were found to be higher in those animals in which the immune complexes were formed from autologous rather than heterologous tissue antigens.

[Foveolar aplasia in tyrosinase-positive oculocutaneous albinisim (author's transl)]. / Foveola-Aplasie bei Tyrosinase-positivem oculocutanen Albinismus. Klinish-pathologische Befunde

The eye of a 47 year old man with tyrosinase-positive oculocutaneous albinism, photophobia, nystagmus and visual acuity 0, 4-0, 5 was histologically examined after orbital exenteration for neoplasia. Histologic serial sections of the centre of the retina showed a continuous 6-8 cell-layer of ganglion cells, without any suggestion of a foveolar pit. The outer layers of the macular retina were altered secondarily by tumor-impression-folds; they were unremarkable at the periphery as were the acid mucopolysaccharides in the receptor region. Electron microscopy of the uvea and the retinal pigment epithelium showed a normal number of pigment granules but a deficiency of melanin, as well as structural anomalies. The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia. The etiology is discussed. An identic anomaly has been described in aniridia, similar ones in other congenital ocular diseases.

[The proof of different types of collagen in the bovine eye (author's transl)]. / Der Nachweis verschiedener Kollagentypen im Rinderauge

Characteristically stained polyacrylamide gels can be obtained by disk-electrophoresis in acid medium of several tissues of the bovine eye. The technique permits to prove different types of collagen in the eye, and allows the differentiation and identification of the tissues. By these results the different tissues of the eye can be divided into three groups. 1. Tissues showing two alpha collagen components in polyacrylamide gel (cornea, sclera, iris, ciliary body, anterior lens capsule, and the pigmented epithelium of the retina). 2. Tissues possessing one alpha component only (zonula fiber and vitreous body). 3. Tissues which show neither the alpha nor the beta and gamma component of collagen (lens nucleous and retina without pigmented epithelium).