In Royal College of Surgeons (RCS) rats with hereditary retinal degeneration loss of retinal pigmented epithelium (RPE) and choriocapillaris is most pronounced in the upper-temporal quadrant. To investigate whether changes in choroidal vasodilative innervation might be involved in the RPE degeneration, we analyzed whole mount preparations of the retina and choroid stained for nitric oxide synthase and for NADPH-diaphorase (d) of 19 dystrophic RCS rats and 24 age-matched congenic controls of different age groups. Density of NADPH-d-positive nerve fibers was quantitatively evaluated in the upper-temporal and lower-nasal quadrant. Our results revealed that even in control animals there were much less positively stained nerve fibers in the upper-temporal than in the lower-nasal quadrant. Nerve fiber density in both quadrants increased for up to 3 months and remained nearly constant throughout life. In the dystrophic animals up to 3 months of age nerve fiber density was similar to that seen in the controls. In dystrophic animals older than 3 months nerve fiber density in the upper-temporal quadrant decreased significantly, whereas density in the lower-nasal quadrant revealed nearly the same values as in the age-matched controls. Decrease of NADPH-d stained nerve fibers in this quadrant occurred prior to the vascular changes in the choriocapillaris. In the retina of RCS dystrophic rats an increase of NADPH-d-positive amacrine cells was found only in 3-month-old animals. Most of these cells were located in the vicinity of irregularly arranged branches of the central retinal artery. In animals 5 months of age and older the number of cells decreased to the same values found in controls, so that we assume that increase of NADPH-d-positive amacrine cells is involved in capillary degeneration or sprouting.

Keywords:
Royal College of Surgeons rat, NADPH diaphorase, Nitric oxide synthase, Choroid, Amacrine cells
1.
Association for Research in Vision and Ophthalmology (1990) ARVO resolution on the use of animals in research. Invest Ophthalmol Vis Sci 31: 228.
2.
Bill, A., S.F. Nilsson (1985) Control of ocular blood flow. J Cardiovasc Pharmacol 7(suppl 3): 96–102.
3.
Bok, D., M.O. Hall (1971) The role of the pigment epithelium in the etiology of inherited retinal dystrophy in the rat. J Cell Biol 49: 664–682.
4.
Bredt, D.S., P.M. Hwang, S.H. Snyder (1990) Localization of nitric oxide synthase indicating a neuronal role for nitric oxide. Nature 347: 768–770.
5.
Caldwell, R.B. (1989) Increased vascular density and vitreo-retinal membranes accompany vascularizations of the pigment epithelium in the dystrophic rat retina. Curr Eye Res 8: 923–937.
6.
Flügel, C., E.R. Tamm, E. Lütjen-Drecoll (1994) Species differences in choroidal vasodilative innervation: Evidence for specific intrinsic nitrergic and VIP-positive neurons in the human eye. Invest Ophthalmol Vis Sci 35: 592–599.
7.
Gerstein, D.D., D.R. Dantzker (1969) Retinal vascular changes in hereditary Visual Cell Degeneration. Arch Ophthalmol 81: 99–105.
8.
Gery, I., P.J. O’Brien (1981) RCS rat macrophages exhibit normal ROS phagocytosis. Invest Ophthalmol Vis Sci 20: 675–679.
9.
Gooch, K.J., C.A. Dangler, J.A. Frangos (1997) Exogenous basal, and flow induced nitric oxide production and endothelial cell proliferation. J Cell Phys 171: 252–258.
10.
Hayreh, S.S. (1974) The choriocapillaris. Albrecht Von Graefes Arch Klin Exp Ophthalmol 192: 165–179.
11.
Hayreh, S.S. (1983) Physiological anatomy of the choroidal vascular bed. Int Ophthalmol 6: 85–93.
12.
Herron, W.L., B.W. Riegel, O.E. Myers, M.L. Rubin (1969) Retinal dystrophy in the rat – A pigment epithelial disease. Invest Ophthalmol Vis Sci 8: 595–604.
13.
Korte, G.E., V. Reppucci, P. Henkind (1984) RPE destruction causes choriocapillary atrophy. Invest Ophthalmol Vis Sci 25: 1135–1145.
14.
Kuwabara, T. (1979) Photic and photo-thermal effects on the retinal pigment epithelium; in Zinn KM, MF Marmor (eds): The Retinal Pigment Epithelium; Cambridge, Harvard University Press, pp 293–313.
15.
Matthes, M.T., D. Bok (1985) Blood vascular abnormalities in animals with inherited retinal degeneration; in LaVail MM, JG Hollyfield, RE Anderson (eds): Retinal Degeneration: Experimental and Clinical Studies. New York, Liss, pp 209–237.
16.
May, C.A., M. Horneber, E. Lütjen-Drecoll (1996) Quantitative and morphological changes of the choroid vasculature in RCS rats and their congenic controls. Exp Eye Res 63: 75–84.
17.
Romeis, B. (1989) Lillie’s fixative; in Romeis B, P Böck (eds): Mikroskopische Technik. München, Urban & Schwarzenberg, vol 17, p 86.
18.
Roufail, E., M. Stringer, S. Rees (1995) Nitric oxide synthase immunoreactivity and NADPH diaphorase staining are co-localised in neurons closely associated with the vasculature in the rat and human retina. Brain Res 684: 36–46.
19.
Sarkar, R., R.C. Webb, J.C. Stanley (1995) Nitric oxide inhibition of endothelial cell mitogenesis and proliferation. Surgery 118: 274–279.
20.
Scherer-Singler, U., S.R. Vincent, H. Kimura, E.G. McGeer (1983) Demonstration of a unique population of neurons with NADPH-diaphorase histochemistry. Neurosci Methods 9: 229–234.
21.
Schreckenberger, M., M. Eichhorn, J. Gottanka, C. Döbig, E. Lütjen-Drecoll (1994) Altered proportions in RCS rat eyes. Exp Eye Res 59: 409–416.
22.
Scott-Burden, T., V.B. Schini, E. Elizondo, D.C. Junquero, P.M. Vanhoutte (1992) Platelet-derived growth factor suppresses and fibroblast growth factor enhances cytokine-induced production of nitric oxide by cultured smooth muscle cells. Effect on cell proliferation. Circ Res 71: 1088–1100.
23.
Snyder, S.H. (1992) Nitric oxide and neurons. Curr Opin Neurobiol 2: 323–327.
24.
Stjernschantz, J., A. Bill (1980) Vasomotor effects of facial nerve stimulation: Noncholinergic vasodilation in the eye. Acta Physiol Scand 109: 45–50.
25.
Su, E.-N., V.A. Alder, D.Y. Yu, S.J. Cringle (1994) Adrenergic and nitrergic neurotransmitters are released by the autonomic system of the pig long posterior ciliary artery. Curr Eye Res 13: 907–917.
26.
Wiencke, A.K., H. Nilsson, P.J. Nielsen, N.C. Berg Nyborg (1994) Nonadrenergic noncholinergic vasodilation in bovine ciliary arteris involves CGRP and neurogenic nitric oxide. Invest Ophthalmol Vis Sci 35: 3268–3277.
27.
Yamamoto, R., D.S. Bredt, T.M. Dawson, S.H. Snyder, R.A. Stone (1993a) Enhanced expression of nitric oxide synthase by rat retina following pterygopalatine parasympathetic denervation. Brain Res 631: 83–88.
28.
Yamamoto, R., D.S. Bredt, S.H. Snyder, R.A. Stone (1993b) The localization of nitric oxide synthase in the rat eye and related cranial ganglia. Neuroscience 54: 189–200.
1998
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.