Ciliary Muscle Capillaries Have Blood–Tissue Barrier Characteristics

doi:10.1006/exer.1998.0483

Experimental Eye Research

Volume 66, Issue 6, June 1998, Pages 747-754

https://doi.org/10.1006/exer.1998.0483 Get rights and content

Abstract

It was determined whether the capillaries in the ciliary muscle are of the blood-tissue barrier or of the permeable non-barrier type. Ciliary body and iris of normal human and animal eyes were examined by electron microscopy and by immunohistochemical staining with a panel of antibodies recognizing endothelial blood–brain barrier markers. In addition, horseradish peroxidase (HRP) tracer studies of the anterior segment were carried out in rabbits. Our results demonstrated that the capillary endothelium in human and rabbit ciliary muscle has few luminal pinocytotic vesicles and a morphological aspect suggesting the presence of tight junctions. Ciliary muscle and iris capillaries stained positive for the blood–brain barrier markers Glucose-Transporter-1 and P-Glycoprotein, while staining for the PAL-E antigen and the transferrin receptor was absent. In the rabbit ciliary muscle, vascular leakage of exogenous HRP tracer was absent. It was concluded that this functional barrier and the observed phenotype of ciliary muscle capillaries are consistent with a blood–tissue barrier function similar to that of the iris microvasculature.

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^☆: Bito, I. Z.Stjernschantz, J.

^f1: Address all correspondence to: R. O. Schlingemann, Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.

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Regular articleCiliary Muscle Capillaries Have Blood–Tissue Barrier Characteristics☆

Abstract

Surv. Ophthalmol.

Int. Rev. Cytol.

Exp. Eye Res.

Brain Res.

Exp. Eye Res.

J. Biol. Chem.

Effect of histamine on the permeability of the ocular vessels

Arch. Ophthalmol.

Permeability of the intraocular blood vessels

Trans. Ophthalmol. Soc.

Uveoscleral drainage of aqueous humor: Physiology and pharmacology

The ocular effects of prostaglandins and other eicosanoids

Multidrug-resistance gene (P-glycoprotein) is expressed by endothelial cells at blood–brain barrier sites

Proc. Natl. Acad. Sci. U.S.A.