Appearance and distribution of neurofilament immunoreactivity in iris nerves

Abstract

We have used antiserum raised against neurofilament (NF) protein and indirect immunofluorescence techniques to visualize neuronal structures in rodent, cat, and cow irides. In the adult rat iris a large population of nerve fibers with a nonautonomic distribution show NF-like immunoreactivity. In whole mounts, smooth fluorescent fibers were seen in a fine-meshed plexus from the sphincter margin to the ciliary processes. Superimposed, a sparse pattern of thick meandering axon bundles were seen. Electroblotting and peroxidase immunochemical staining techniques unequivocally showed the presence of all three NF polypeptides in the adult rat iris. Adult mouse irides showed a somewhat sparser pattern of NF-positive nerves than that of the rat. Adult guinea pig irides contained irregular NF-positives fibers and few axon bundles. In cryostat-sectioned cat iris numerous irregularly distributed individual fibers were found, whereas in similarly sectioned cow iris thick NF-positive axon bundles were more numerous. By embryonic day 18 numerous sparse NF-positive axons were seen, and the subsequent gradual increase in both axons in bundles and fine-meshed plexuses of individual fibers produced an appearance similar to that in the adult by 6 days of postnatal age. One week after grafting of irides to the anterior eye chamber, most NF-positive nerves had disappeared from the iris grafts. Sympathetic and parasympathetic denervation of the irides did not influence the distribution of the NF-positive iris nerves. Five days after electrothermal lesion of the trigeminal nerve just distal to its ganglion a large proportion of the NF-positive nerves had disappeared from the iris. All perikarya in the parasympathetic ciliary and most perikarya in the superior cervical sympathetic and in the trigeminal sensory ganglion showed NF immunoreactivity. The present report shows a way to visualize nonautonomic nerve populations in stretch-prepared as well as sectioned irides by immunofluorescence techniques using an antiserum to neurofilament protein.

Disappearance Of Catecholamine Fluorescence From The Adrenergic Nerves In Arterial Grafts In Rats: An Experimental Fluorescence Histochemical Study

“…Vasospasm or any other underlying reason for thrombosis is a threat to the survival of the ap (28). Increased understanding of the mechanisms behind vasospasm is of crucial importance for the wellbeing of the vascular pedicle or arterial graft.…”

“…Black bar = 100 mm. immunohistochemically and by glyoxylic acidinduced uorescence (28,29). Speci c histochemical demonstration of catecholamines in various tissues has been possible since development of the formaldehyde-induced uorescence method (6)(7)(8) and the glyoxylic acid-induced uorescence method (1,21,29).…”

“…The resolution of catecholamines improved after glyoxylic acid was introduced as a condensation agent (21,29). Many modi cations of the glyoxylic acid method have been published (17,28,31,36). The speci city and sensitivity of the glyoxylic acidinduced method is well established (13,14,16,31,32,36,37) and the method has been found to be useful in histochemical studies on the degeneration and regeneration of adrenergic nerves following surgery (15).…”

Immunohistochemical demonstration of the nerves in human dental pulp with antisera against neurofilament protein and glia-specific S-100 protein.

“…A majority of the NFP-positive nerve fibers, except the fibers supplying the vessels, are considered to be sensory nerves, since several experimental studies to resect the inferior alveolar nerve have suggested a sensory origin for the pulpal nerves (CoRPRON et al, 1972;ARWILL et al, 1973). Sensory nerves showing intense NFP-immunoreactivity were also found in the skin (IWANAGA et al, 1982;DALSGAARD et al, 1984) and iris (SEIGER et al, 1984).…”

Noradrenaline levels rise significantly in rat arterial grafts at 6 hours postoperatively, and take 48 hours to come down

“…4À7 In our previous morphological study, noradrenaline-induced fluorescence disappeared almost completely from rat arterial grafts within 24 h, 8 and we established the rate of disappearance and regrowth of various neuronal elements such as neurofilaments and enzymes involved in the synthesis of colinergic and adrenergic neurotransmitters in the grafts (Penttila¨et al, unpublished findings). Other works showed that sympathetic nerves disappear from transplanted or denevated irides within 28À36 h. 9 Vasoconstriction results from the stimulation of a-adrenergic receptors in arterial smooth muscle by noradrenaline. 10À12 The objective of this study was to quantitatively assess graft noradrenaline content in the early postoperative period in rats by using the highly sensitive method of high-performance liquid chromatography (HPLC).…”