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D L Wang

Publications and source records attributed to D L Wang.

76 records · Page 5Linked to original sources
PubMed1983

Studies on the half-life and the distribution of stearoyl-CoA desaturase in the housefly.

The half-life of the stearoyl-CoA desaturase was determined by using houseflies injected with puromycin. The LD50 for puromycin was determined to be 1.55 micrograms/mg body wt for both sexes. By following the decay in specific activity of the desaturase after puromycin injection, the half-life of this enzyme in 4-day-old females was calculated to be 9.35 hr, while in 1-day-old females it was 3.38 hr. The inhibition curve for the 3-day-old males never reached 100%, and a biphasic curve was observed. The early phase resulted in a half-life of the desaturase of 2.41 hr, while the latter phase had a half-life of 8.45 hr. In general, it appeared that the half-life of the desaturase increased with age in either sex. Studies on the distribution of desaturase activity within the housefly showed that most of the activity was present in the integument; however, in the female, the onset of ovarian development seemed to shift the distribution of desaturase from the integument, towards the internal tissues. In the male, there appeared to be equal amounts of desaturase in integument and the fat body plus internal tissues at day 2, but by day 5 most of the activity was associated with the integument. The high specific activity and high percentage of total desaturase activity associated with integument coupled with the shift of distribution of desaturase in females during the onset of ovarian development may be indicative of a close correlation of the desaturase with alkene synthesis and possibly sex pheromone production.

Animals↗
PubMed1983

Ethanol ingestion and polyunsaturated fatty acids: effects on the acyl-CoA desaturases.

The ingestion of ethanol results in altered compositions of the polyenoic fatty acids in a variety of liver and brain membranes. A possible cause for these alterations in hepatic endoplasmic reticulum membranes has been studied by measuring the delta 9, delta 6, and delta 5 acyl-CoA desaturase activities in hepatic microsomes from chronically or acutely treated rats. Chronically, ethanol decreased all three enzyme activities with the following order of sensitivity: delta 6 (65%), delta 9 (54%), and delta 5 (46%). The short-term study indicated that all three desaturase activities were affected after 1 day of ethanol feeding. NADPH- and NADH-cytochrome c reductase activities were found to be reduced in chronically treated rats, and the NADH-cytochrome c reductase was decreased in the acutely treated. However, these reduced enzyme activities could not account for the decrease in desaturase activities due to the very marked differences between the specific activities of these enzymes compared to the desaturase. Thus, we conclude that changes in membrane polyenoic fatty acid composition can be result of ethanol-induced decreases in the terminal desaturase enzymes.

Animals↗