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W H Friend

Publications and source records attributed to W H Friend.

6 recordsLinked to original sources
PubMed1986

Metabolic and mitochondrial disturbances in streptozotocin-treated Sprague-Dawley and Sherman rats.

This study provides explanation for conflicting evidence in the literature relating to changes in mitochondrial function and metabolic parameters during chemically induced diabetes. Diabetes of 3 days' duration (early ketosis) did not alter heart, kidney, or liver mitochondrial respiratory rates with glutamate or succinate even though serum glucose and triglycerides were elevated. Diabetes of 5 weeks' duration did not alter kidney or liver mitochondrial function in the fed adult rat although weight gain was depressed. The amount of kidney mitochondrial protein isolated per gram of tissue was increased by 30% in the diabetic. This increase was reversed by insulin treatment as were the other biochemical modalities measured. Superimposition of a 24-hr fast resulted in enhanced gluconeogenesis as measured by an animal weight loss of 17% within 24 hr (liver weight loss, 21%) and an elevation of serum urea nitrogen by 180% compared to fasted control. Respiratory rates of diabetic kidney mitochondria with glutamate were unaffected in the fasted animal whereas diabetic liver mitochondrial respiratory rates during succinate oxidation were reduced by 43%. Respiratory control was unchanged in the fasted diabetic rat. All the observed changes were reversed by insulin. Variation in the serum and liver metabolic indices (urea nitrogen, creatinine, glycerol, free fatty acids, free amino acids, triglycerides, and glucose) and liver mitochondrial responses to 7 weeks of chemically induced diabetes was affected by the rat strain, Sprague-Dawley versus Sherman, and rat weight, 72 g versus 222 g. Liver mitochondrial respirations in fed Sherman rats were not depressed by diabetes. Both rat strains had elevated liver free fatty acids and glutamate dehydrogenase activity in the diabetic state. Serum leucine, isoleucine, and valine were more elevated and serum lysine and arginine were more depressed in the diabetic Sprague-Dawley rat than in the Sherman rat. Conjectures on these results are presented in the text.

Age Factors↗
PubMed1978

Depression by ethionine of phosphorylating oxidation in hepatic mitochondria.

Induction of hepatic steatosis and suppression of hepatic ATP levels, protein synthesis and gluconeogenesis subsequent to administration of ethionine may be consequences of interference by this compound with mitochondrial phosphorylation of ADP. The mitochondrial dysfunction is not a direct action of ethionine on the organelle.

Adenosine Triphosphate↗
PubMed1975

Ethidium bromide inhibits mitochondrial phosphorylating oxidation.

Ethidium bromide, in addition to combination with mitochondrial nucleic acids, is a phosphorylation inhibitor during glutamate and succinate respiration by mitochondria. Exhaustive washing of ethidium bromide-treated mitochondria did not relieve the inhibition nor significantly decrease the amount of bound dye. Dialysis against a cation exchange resin at 3 degrees for 17 hr removed about 97% of bound dye. This restored phosphorylating capacity to that of untreated mitochondria which had also been dialyzed against the resin. Since state 3 respiration was diminished and state 4 was unaffected by the presence of the acridine dye, and since neither swelling of mitochondria nor release of latent ATPase was observed, then ethidium bromide was not an electron transport inhibitor nor an uncoupler of oxidative phosphorylation. Inhibition of metabolic processes by ethidium bromide may be due in part to depressed generation of mitochondrial ATP.

Adenosine Triphosphatases↗