Kaarina Tervo

Immunoreactivity for substance P in the gasserian ganglion, ophthalmic nerve and anterior segment of the rabbit eye

SummaryThe distribution of substance P (SP) immunofluorescence was investigated in the Gasserian ganglion, ophthalmic nerve and in the anterior segment of the rabbit eye. About one third of the nerve cell bodies in the Gasserian ganglion exhibited SP immunofluorescence, which was also observed in some nerve fibres of the ophthalmic nerve. In the cornea, some SP-positive iris contained numerous nerve fibres with SP immunofluorescence. In the sphincter area such fibres were circular, while the orientation of the SP fibres was radial in the dilator muscle. Both in the iris and in the ciliary body, the largest vessels were surrounded by nerves exhibiting SP immunofluorescence. A few nerve fibres also appeared in the stroma of the ciliary processes.

Corneal wound healing and nerve morphology after excimer laser in situ keratomileusis in human eyes.

BACKGROUND Our aim was to describe wound healing and nerve regeneration in the human cornea after excimer laser in situ keratomileusis. METHODS Excimer laser in situ keratomileusis was done in three human eyes 8 days, 54 days, and 4 months prior to enucleation. Acetylcholinesterase reaction was used to histochemically demonstrate the corneal nerves. Immunohistochemical methods were used to demonstrate the following wound healing proteins: cellular fibronectin, tenascin, transforming growth factor-beta 1, and alpha-smooth muscle actin. RESULTS All corneas healed without complication. No epithelial hyperplasia appeared and the Bowmans layer was smooth and acellular. An epithelial plug extending up to 100-300 microns under the flap margins was seen in all specimens. Regenerative nerve fiber bundles emerging from sharply cut anterior stromal nerves were observed, but the deeper nerves were normal. Restricted expression of fibronectin and tenascin was found at the wound area. All corneal cell types were positive for transforming growth factor-beta 1 antibody. Cells lining the limbal vessels were positive for alpha-smooth muscle actin antibody whereas the corneal cells were negative. CONCLUSIONS The nerve morphology showed only a few abnormalities, especially in deep stromal nerves. Epithelial plugs at the flap margins may maintain a delayed wound healing process for several months but otherwise the process remained active for a relatively short time.

Effect of sensory and sympathetic denervation on substance P immunoreactivity in nerve fibres of the rabbit eye

Abstract Substance P (SP) immunoreactivity was demonstrated in ocular tissues of rabbit. SP was found in nerve fibres of cornea iris, ciliary body, choroid and in the inner plexiform layer of the retina. In order to verify the origin of these nerves the animals were subjected to two different denervation procedures: intracranial combined maxillary and ophthalmic neurotomy or superior cervical ganglionectomy. The former operation destroyed all SP immunoreactive nerves of the ipsilateral eye except for the retina, whereas the latter had no effect. It is concluded that the ocular SP immunoreactive nerves are sensory trigeminal fibres. SP immunoreactivity in the retina is not due to sensory nerves but probably to amacrine cells.

Immunohistochemical demonstration of epidermal growth factor in the lacrimal and submandibular glands of rats.

Abstract. The extraorbital and intraorbital lacrimal glands, the Harderian glands, and the submandibular glands of five rats were excised after ethanol perfusion under general anesthesia. Indirect immunohistochemistry with antibodies specific to epidermal growth factor (EGF) was performed. EGF‐like immunofluorescence (EGF‐LI) was shown to be present both in the lacrimal glands (extra‐ and intraoribtal) and in the submaxillary gland. In the lacrimal glands the specific immunoreaction appeared within the lumen of the acini and the cells of the tubular ducts close to the acini. Only faint EGF‐LI was observed within the acinar cells. The submandibular glands showed intense EGF‐LI only in the cells of the granular convoluted tubules. The Harderian gland did not show any EGF‐LI. The results strongly support the idea that the lacrimal gland is a source of EGF in tear fluid (TF). Diseases of the lacrimal gland therefore may lead to decreased concentrations of EGF in tears. This may account in part for the pathophysiology of tear deficiency syndromes and may serve as the basis of a new rationale for the external application of EGF.

Vasoactive intestinal polypeptide-like immunoreactive nerves to the human eye

Abstract Using immunohistochemical techniques, vasoactive intestinal polypeptide (VIP) is visualized in nerves distributed to the human eye. Immunoreactive nerve Fibers occur about limbal blood vessels and within the trabecular meshwork. In the iris, free‐running stromal nerves are the most common, but nerves to both dilator and sphincter muscles are present as well. Immunoreactive nerves are seen within the ciliary mucle and occasionally within a ciliary process. Innervation to choroidal blood vessels constitutes a prominent feature; innervation to more anterior uveal blood vessels is seen only irregularly. Immunoreactive to more anterior uveal blood vessels is seen only irregularly. Immunoreactive nerves are apposed to melanocytes throughout the uvea. The present findings extend prior reports in the human eye, indicating a potential role for VIP in ocular physiology. Additional neuroanatomical, biochemical and physiological studies are necessary to define fully the ocular function of VIP and to determine ultimely whether VIP has clinical and pharmacological implications.

Expression of tenascin and fibronectin in the rabbit cornea after excimer laser surgery

In order to investigate the effects of excimer laser surgery on corneal wound healing, 25 rabbits underwent anterior keratectomy at a depth of 100 or 300 μm with a Meditec MEL 50 excimer laser. After various intervals the animals were killed and the cornea excised and investigated immunohistochemically for the expression of extracellular matrix (ECM) proteins, fibronectin and tenascin. Fibronectin was shown to occur earlier than tenascin, and the two also had different distribution patterns. Wound depth showed no clear effect on the localization and time of ECM protein expression. This study indicates that corneal wounds caused by excimer laser radiation and those caused by mechanical surgery differ as to healing mechanisms.

Plasminogen activator and its inhibitor in the experimental corneal wound

Anterior keratectomy was performed to 10 eyes of 8 adult rabbits. The animals were killed 3-24 hr after wound closure. The corneas were excised and subjected to histochemical demonstration of urokinase-type plasminogen activator (u-PA), tissue-type PA (t-PA) and plasminogen activator inhibitor [PAI-1) using commercial antibodies. A strong immunoreaction for u-PA, a weaker reaction for PAI-1 and a very weak t-PA-like immunoreaction appeared in the anterior stroma of the wounded area. None of the antisera used showed any immunostaining in the cornea outside the wound. The role of the plasminogen activator-plasmin system in the healing of the corneal wound is discussed.

Wound Healing of the Ocular Surface

Wound healing is a complex, long-lasting regulatory sequence that involves expression of a number of genes, which are active during the individuals development. Some of the phenomena differ from normal tissue turnover and growth only quantitatively. This article reviews the current data on corneal wound healing, with particular reference to mesenchymal matrix proteins and their integrin receptors, to growth factors and to proteolytic enzymes. Some inflammatory mediators are also discussed. The theoretical basis for therapeutic interventions is also discussed briefly, in the light of present knowledge.

Immunohistochemical demonstration of cellular fibronectin and tenascin in human epiretinal membranes.

Abstract The occurrence of fibronectin, cellular fibronectin and tenascin was studied immunohistochemically in epiretinal membranes from 5 patients with retinal detachment and 3 patients with macular pucker, and in preretinal membranes from 3 patients with proliferative diabetic retinopathy. Positive immunofluorescence for these proteins was seen in all specimens studied. The presence of cellular fibronectin suggests that local production of fibronectin occurs in these membranes. The expression of tenascin, an extracellular matrix glycoprotein, originally found to modulate organosenesis in tendinous and glial tissue, suggests that this glycoprotein also participates in the regulation of cellular growth in these membranes.

Demonstration of tenascin-like immunoreactivity in rabbit corneal wounds

Abstract Tenascin, a novel extracellular matrix protein, was demonstrated immunohistochemically in rabbit corneas that had healed after anterior keratectomy. Tenascin‐like immunofluorescence (T‐LI) appeared in the corneal stroma at the wound area only. The wound edge showed the most intense specific fluorescence. The corneal epithelium, in general, displayed a moderate T‐LI. Wounding did not induce any change in epithelial T‐LI or T‐LI located in the stroma outside the wound.