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The gross and microscopical dimensions of small intestines from 12-week old streptozotocin-diabetic rats receiving no therapeutic intervention were compared with those from animals receiving insulin alone or in conjunction with the aldose reductase inhibitor, ponalrestat. Four regions along each intestine were analysed stereologically. Insulin had significant beneficial effects on body weight as well as on intestinal length, width, surface area and volume. In contrast, ponalrestat did not improve body weight deficits and was associated with crypt hypertrophy and a reduced villous surface/crypt volume ratio. There were interaction effects between insulin and ponalrestat for intestinal length and primary mucosal surface area. All groups displayed significant regional differences in surface area of primary mucosa and volume of muscularis externa. Only untreated diabetic rats failed to reveal regional variation in the surface area and volume of villi. Ratios of villous surface area/crypt volume varied from region-to-region in insulin-treated diabetic rats but not in other groups. The study fails to reveal any beneficial effect of aldose reductase inhibition on the changes in intestinal morphology seen in experimental diabetes.

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Normal, rachitic, and vitamin D3-replete chicken growth plates were studied utilizing the potassium pyroantimonate-osmium tetroxide procedure. A marked membrane and mitochondrial calcium was revealed in all specimens in the maturing and early hypertrophic zones which disappeared as heavy matrix mineralization began. The most significant difference shown in the specimens was in the marked intracellular lipid content of chondrocytes in all zones of the rachitic and D3-replete growth plates. There was negligible lipid present in normal specimens. It is suggested that as most of the mechanisms postulated as necessary for calcification are present in rachitic chicks, perhaps the increased intracellular lipid pool results from the formation of abnormal lipids for insertion into the plasma membrane and thus prevents normal calcium transport. Chains of intracellular vesicles were also visualized in maturing and hypertrophic chondrocytes. These were more often seen in rachitic growth plates and in increased numbers in the early D3-replete specimens. The etiology is unknown at the present time.