John N. Hawthorne

Learn More
A possible relationship between increased sorbitol concentration and decreased myo-inositol concentration in peripheral nerves of diabetic rats has been examined. To this end, sorbinil, an aldose reductase inhibitor, was used either to prevent or reverse elevation of nerve sorbitol concentration in diabetic rats. Sorbinil treatment at 20 mg · kg-1 · day-1(More)
Acute diabetes with ketosis was induced in rats by intraperitoneal streptozotocin and also a milder form of diabetes without ketosis by injecting less of the drug. The acutely diabetic rats were killed 72h after injection and the others after either 2 or 13 weeks. Free and lipid myo-inositol was then measured in various tissues and body fluids by g.l.c. of(More)
Sciatic nerves removed post-mort`em from diabetic patients and normal subjects were analysed by gas chromatography for glucose, fructose, sorbitol and myo-inositol. The concentrations of free and lipid inositol were significantly lower in nerves from the diabetic than from the control group. Concentrations of glucose, fructose and sorbitol were higher in(More)
Samples of brain anterior temporal cortex from 17 patients with Alzheimer's disease and 18 age-matched controls have been analysed for myo-inositol and the three phosphoinositides. There was significantly less phosphatidylinositol in the Alzheimer samples (1.36 mumol/g wet weight) than in the controls (2.28 mumol/g). The concentrations of(More)
Motor nerve conduction velocity was lower in streptozotocin-diabetic rats than in controls. Treatment with the aldose reductase inhibitor Sorbinil restored conduction velocity to normal. Diabetic rats had an increased concentration of sorbitol and reduced free inositol in sciatic nerve. Sorbinil corrected both defects. Inositol administration to diabetic(More)
1. Acetylcholine produced a fivefold increase in the specific radioactivity of phosphatidylinositol in guinea-pig pancreas slices incubated in the presence of [(32)P]-orthophosphate, but did not affect the specific radioactivity of the terminal phosphate of ATP. 2. The secretagogues acetylcholine and pancreozymin had no direct effect on the enzymes of(More)
Chromaffin cells of bovine adrenal medulla release catecholamines in response to activation of nicotinic ACh receptors which open voltage-sensitive calcium channels. Catecholamine secretion by exocytosis requires an increase in cytosolic free calcium. The cells also possess muscarinic ACh receptors but muscarinic agents do not provoke catecholamine release.(More)