Biomedical subjects

A Beyer-Mears

Publications and source records attributed to A Beyer-Mears.

27 records · Page 2Linked to original sources

PubMed1984

Partial preservation of motor function by inhibition of arachidonate metabolism in rats with phospholipase A2-induced caudate lesions.

Dexamethasone pretreatment prevents motor impairment manifested by ipsilateral rotation and phospholipid alterations resulting from phospholipase A2-induced caudate nucleus lesions in rats. If motor function preservation is attributed solely to the antiprostaglandin activity of dexamethasone, then indomethacin (an inhibitor of cyclooxygenase) and phenidone (an inhibitor of both lipoxygenase and cyclooxygenase) should also diminish rotation. Phenidone offered dose-related, partial protection whereas indomethacin did not. Histologic sections of rat brain indicated that a positive correlation existed between the size of the caudate lesion and number of rotations for the various treatments. Because dexamethasone produced essentially complete protection, it is hypothesized that dexamethasone protects caudate motor function by interfering with breakdown of membrane phospholipids, as well as by preventing formation of arachidonate and its products.

Animals↗

PubMed1984

Glomerular polyol accumulation in diabetes and its prevention by oral sorbinil.

Although enhanced activity of the polyol pathway has been implicated in the pathogenesis of certain complications of diabetes, evidence that aldose reductase activity and sorbitol content are increased in the characteristic tissue site of the diabetic renal lesion has been lacking. We therefore measured polyols in glomeruli isolated from control and streptozotocin-diabetic rats, and assessed whether changes in diabetic glomeruli could be prevented by oral administration of the aldose reductase inhibitor sorbinil . Compared with control, polyol content of glomeruli isolated from diabetic rats was increased 10-fold and fourfold at 6 and 9 wk, respectively, after induction of diabetes, but was unchanged in glomeruli from rats treated with sorbinil throughout the experimental periods. In contrast, glomerular myo-inositol content was reduced in diabetic samples; this fall in myo-inositol levels was also completely prevented by sorbinil . These results establish that glomeruli contain aldose reductase activity and provide the first demonstration that glomerular polyol content increases while myo-inositol content decreases in diabetes and that oral sorbinil prevents these changes despite persistent hyperglycemia.

Aldehyde Reductase↗

PubMed1982

Sorbinil protection of lens protein components and cell hydration during diabetic cataract formation.

Topical application of Sorbinil, a potent aldose reductase inhibitor, preserved lens growth, cell hydration and protein components--alpha, beta and gamma crystallins. The concomitant protective effects of Sorbinil were established on the three lenticular parameters because their quantitation offered a comprehensive index of lens integrity during galactose cataractogenesis. The fused eyelids of the rat neonate provided a natural delivery chamber, an orbital pouch, for topical administration of inhibitor to the treated lens; the contralateral pouch served as an untreated control. Protein preservation was determined by gel filtration chromatography. In galactose-maintained neonates, untreated lenses exhibited only 50% of the normal fraction-II component, whereas Sorbinil treatment maintained 95% of the protein. Likewise, quantitative analysis of scanning electron micrographs indicated that Sorbinil protected lenses against both intra- and extracellular fluid accumulation as determined by measurements of individual fiber cell thickness, density (the number of cells/10 micrometer cortex), and interdigitation. In addition, Sorbinil-treatment maintained normal growth as evidenced by radius and dry weight measurements. In normal neonates, Sorbinil had no effect on these parameters. These results indicate that changes in lens growth, fiber ultrastructure and protein components respond to aldose reductase inhibition by Sorbinil, thereby diminishing cataractogenesis.

Aldehyde Reductase↗

PubMed1982

Xanthone-2-carboxylic acid effect on lens growth, hydration and proteins during diabetic cataract development.

The concomitant protective effects of the aldose reductase inhibitor, 7-dimethylsulfamoyl-xanthone-2-carboxylic acid, were established by three lens parameters (soluble crystallin proteins, growth and cell hydration) because their quantitation provided a comprehensive index of lens physiology during sugar cataractogenesis in the rat neonate. Their fused eyelids provided the orbital pouch for topical administration of inhibitor to the treated lens; the contralateral pouch served as an untreated control. Protein preservation was determined by gel filtration chromatography. In galactose-maintained neonates, untreated lenses exhibited only 50% of the normal Fraction II protein whereas xanthone-treatment maintained 73% of this component. Quantitative analysis of scanning electron micrographs indicated that xanthone-treatment partially protected lenses against both intra and extracellular fluid accumulation as determined by measurements of individual fiber cell thickness, density (the number of cells/10 micron cortex), and interdigitation. In addition, xanthone-treatment improved lens growth as evidenced by radius and dry weight measurements. Our results suggest that topically applied xanthone partially inhibited sugar cataractogenesis.

Aldehyde Reductase↗

PubMed1980