Summary
Acute hypertension, experimentally induced by intravenous injection of metaraminol in adult rabbits, rapidly induced a damage of the blood-brain barrier in the cerebral cortex, as visualized by Evans-blue-conjugated albumin and horseradish peroxidase. Extravasation of these two exogenous tracers was demonstrated to occur in arterioles, in capillaries and, rarely, in venules. Peroxidase passed the endothelial cell into the nervous tissue in either of three different ways, i. e. through channels, often sigmoidshaped, in the cytoplasm, and transendothelial pinocytosis. The third pathway could, although rarely, be demonstrated between adjacent endothelial cells after cleavage of junctional complexes. The tracer peroxidase was further spread along the blood vessel within the basement membrane and in the extracellular space of the brain. Damaged endothelial cells with diffuse cytoplasmic peroxidase activity and large vesicles were occasionally observed within the areas with blood-brain barrier injury. There were also signs of increased pinocytotic activity in endothelial cells outside the barrier damaged cortical areas. Nerve cells and neuroglial cells could show either a diffuse cytoplasmic peroxidase activity or a vesicular location of the tracer, or sometimes both.
The observations are discussed in relation to previous studies on the mechanism of transendothelial passage of protein tracers at blood-brain barrier damage.
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References
Ashton, N.: The eye in malignant hypertension. Trans. Amer. Acad. Ophthal. Otolaryng.76, 17–40 (1972)
Björkerud, S., Hansson, H.-A., Bondjers, G.: Subcellular valves and canaliculi in arterial endothelium and their equivalence to so-called stigmata. Virchows Arch., Abt. B, Zellpath.11, 19–23 (1972)
Byrom, F. B.: The pathogenesis of hypertensive encephalopathy and its relation to the malignant phase of hypertension; experimental evidence from the hypertensive rat. Lancet1954 II, 201–211
Eto, T., Omae, T., Yamamoto, T.: An electron microscope study of hypertensive encephalopathy in the rat with renal hypertension. Arch. Histol. Jap.33, 133–143 (1971)
Giacomelli, F., Wiener, J., Spiro, D.: The cellular pathology of experimental hypertension. V. Increased permeability of cerebral arterial vessels. Amer. J. Path.59, 133–159 (1970)
Goldby, F. S., Beilin, L. J.: How an acute rise in arterial pressure damages arterioles. Electron microscopic changes during angiotensin infusion. Cardiovasc. Res.6, 569–584 (1972)
Johansson, B.: Blood-brain barrier dysfunction in acute arterial hypertension. Thesis, Göteborg 1974
Johansson, B., Li, C.-L., Olsson, Y., Klatzo, I.: The effect of acute arterial hypertension on the blood-brain barrier to protein tracers. Acta neuropath. (Berl.)16, 117–124 (1970)
Johansson, B., Linder, E.: Blood-brain barrier dysfunction in acute arterial hypertension induced by aortic clamping. Acta neurol. scand.50, 360–365 (1974)
Karnovsky, M. J.: A formaldehyde-glutaraldehyde fixative of high osmolarity for use in electron microscopy. J. Cell Biol.27, 137A (1965)
Karnovsky, M. J.: The ultrastructural bases of capillary permeability studied with peroxidase as a tracer. J. Cell Biol.35, 213–236 (1967)
Kung, P. C., Lee, J. C., Bakay, L.: Electron microscopic study of experimental acute hypertensive encephalopathy. Acta neuropath (Berl.)10, 263–272 (1968)
Olsson, Y., Hossmann, K.-A.: Fine structural localization of exudated protein tracers in the brain. Acta neuropath. (Berl.)16, 103–116 (1970)
Onoyama, K., Omae, T.: Leakage of serum proteins in brain tissues in experimentally induced renal hypertension. Acta neurol. scand.49, 339–344 (1973)
Reese, T. S., Karnovsky, M. J.: Fine structural localization of a blood-brain-barrier to exogenous peroxidase. J. Cell Biol.34, 207–217 (1967)
Rodda, R., Denny-Brown, D.: The cerebral arterioles in experimental hypertension. Amer. J. Path.49, 53–76 (1966)
Steinwall, O., Klatzo, I.: Selective vulnerability of the blood-brain barrier in chemically induced lesions. J. Neuropath. exp. Neurol.25, 542–559 (1966)
Wiener, J., Lattes, R. G., Meltzer, B. G., Spiro, D.: The cellular pathology of experimental hypertension. Amer. J. Path.54, 187–194 (1969)
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Hansson, HA., Johansson, B. & Blomstrand, C. Ultrastructural studies on cerebrovascular permeability in acute hypertension. Acta Neuropathol 32, 187–198 (1975). https://doi.org/10.1007/BF00696568
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DOI: https://doi.org/10.1007/BF00696568