TY - JOUR
T1 - The retinal microvasculature of spontaneously diabetic BB rats
T2 - Structure and luminal surface properties
AU - Fitzgerald, Malinda E.C.
AU - Caldwell, Ruth B.
N1 - Funding Information:
The authors are grateful to Dr. S. S. Solomon and Dr. J. Hessler (Animal Resources Division of the University of Tennessee, The Health Science Center, Memphis, TN) for maintaining the spontaneously diabetic and control BB/Wor-UTM rat colony. This work was supported by EY-04618 and the Juvenile Diabetes Foundation to RBC and the State of Tennessee Neuroscience Center of Excellence Postdoctoral Fellowship to MECF. The authors would also like to acknowledge the excellent technical assistance of S. Frase, D. Lum, S. Slapnick, and S. Will.
PY - 1990/1
Y1 - 1990/1
N2 - Endothelial cell permeability and luminal surface anionic sites were studied in the retinal microvasculature of spontaneously diabetic rats. Horseradish peroxidase (HRP) was used as a tracer of pinocytotic transport, and cationized ferritin (CF) was used as a marker of luminal surface anionic sites. Diabetic and control rats were injected with HRP, and their retinas were fixed. Retinal tissue sections were then incubated in CF, reacted to visualize HRP, and prepared for quantitative electron microscopic analysis. In both control and diabetic rats treated with serotonin and histamine antagonists to prevent HRP-induced vascular changes, the endothelium formed a barrier to the tracer. Pinocytotic uptake was relatively low in most vessels. Reaction product was restricted to pinocytotic vesicles, tubular cisternae, and multivesicular bodies. HRP uptake appeared high in some of the deep capillaries of the diabetic retinas as compared with that of the controls, but the difference was not statistically significant. HRP-induced transendothelial permeability was observed in both control and diabetic rats when serotonin and histamine antagonist pretreatment was omitted. CF studies showed anionic sites in four luminal surface microdomains in control and diabetic endothelial cells. CF-binding, anionic sites were present on the plasma membrane, on all coated vesicles, on some uncoated vesicles, and on most diaphragms of uncoated vesicles. Plasma membrane binding was sparse and patchy in some diabetic vessels, especially in the deep vessels of rats that were not treated with the serotonin and histamine antagonists. However, statistical analysis showed similar numbers of plasma membrane binding sites in diabetic and control rats pretreated with serotonin and histamine antagonists. Our data suggest that the retinal microvasculature in diabetic rats remains normal in terms of permeability and luminal membrane anionic charge. (Preliminary report was presented at the Society for Neuroscience; M. E. C. Fitzgerald and R. B. Caldwell, 1987, Soc. Neurosci. Abstr., 13, 773.).
AB - Endothelial cell permeability and luminal surface anionic sites were studied in the retinal microvasculature of spontaneously diabetic rats. Horseradish peroxidase (HRP) was used as a tracer of pinocytotic transport, and cationized ferritin (CF) was used as a marker of luminal surface anionic sites. Diabetic and control rats were injected with HRP, and their retinas were fixed. Retinal tissue sections were then incubated in CF, reacted to visualize HRP, and prepared for quantitative electron microscopic analysis. In both control and diabetic rats treated with serotonin and histamine antagonists to prevent HRP-induced vascular changes, the endothelium formed a barrier to the tracer. Pinocytotic uptake was relatively low in most vessels. Reaction product was restricted to pinocytotic vesicles, tubular cisternae, and multivesicular bodies. HRP uptake appeared high in some of the deep capillaries of the diabetic retinas as compared with that of the controls, but the difference was not statistically significant. HRP-induced transendothelial permeability was observed in both control and diabetic rats when serotonin and histamine antagonist pretreatment was omitted. CF studies showed anionic sites in four luminal surface microdomains in control and diabetic endothelial cells. CF-binding, anionic sites were present on the plasma membrane, on all coated vesicles, on some uncoated vesicles, and on most diaphragms of uncoated vesicles. Plasma membrane binding was sparse and patchy in some diabetic vessels, especially in the deep vessels of rats that were not treated with the serotonin and histamine antagonists. However, statistical analysis showed similar numbers of plasma membrane binding sites in diabetic and control rats pretreated with serotonin and histamine antagonists. Our data suggest that the retinal microvasculature in diabetic rats remains normal in terms of permeability and luminal membrane anionic charge. (Preliminary report was presented at the Society for Neuroscience; M. E. C. Fitzgerald and R. B. Caldwell, 1987, Soc. Neurosci. Abstr., 13, 773.).
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U2 - 10.1016/0026-2862(90)90056-W
DO - 10.1016/0026-2862(90)90056-W
M3 - Article
C2 - 2314305
AN - SCOPUS:0025091832
SN - 0026-2862
VL - 39
SP - 15
EP - 27
JO - Microvascular Research
JF - Microvascular Research
IS - 1
ER -
