Sequential morphological and permeability changes in the rete capillaries during hyperglycaemia.
With the rete model of the eel swimbladder, we have studied the appearance and development of a microangiopathy during a 2-year period of hyperglycaemia. Hyperglycaemia was induced in the eel by chronic exposure to cold water. At 3-5 months, basement membrane thickness was twice the normal value and increased only slightly thereafter. Diffusion coefficients of permeability were measured in counter-current perfusion experiments for a variety of tracers that are believed to use different pathways of transcapillary transport. The permeability to sucrose was the first to significantly increase, at 6-8 months, followed by that of albumin, insulin, and inulin, at 9-11 months and that of sodium, at 18-24 months. The permeability to water and antipyrine remained stable throughout the study. The results indicate that in the rete model, chronic hyperglycaemia induces a rapid thickening of the capillary basement membrane and selective permeability increments in the various paths of transcapillary transport.
Rasio
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Department of Medicine, Université de Montréal, Montreal, Quebec, Canada. rasioe@medclin.umontreal.ca
Bendayan
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D000400:Air Sacs / Q000098:blood supply* / Q000648:ultrastructure; D000818:Animals; D001485:Basement Membrane / Q000648:ultrastructure; D002196:Capillaries / Q000503:physiopathology / Q000648:ultrastructure*; D002199:Capillary Permeability / Q000502:physiology*; D003925:Diabetic Angiopathies / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004524:Eels; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000473:pathology / Q000503:physiopathology*; D011897:Random Allocation; D013696:Temperature