Influence of follicular maturation on the susceptibility of chicken ovarian granulosa cells to free oxygen radicals.

The influence of ovarian follicular maturation on lipid peroxidation-induced changes in the fluidity of plasma membrane of granulosa cells was investigated using the fluorogenic polyunsaturated fatty acid cis-parinaric acid (cPNA). An increase in lipid peroxidation results in the decrease of fluorescence intensity of cPNA. A decrease in membrane fluidity results in the decrease of fluorescence polarization of cPNA.

Phospholipid degradation is induced by heat in alpha-tocopherol-enriched eggs.

A comparative study was undertaken to determine the effect of an alpha-tocopherol- and iodine-enriched laying diet on the phospholipid profile of egg yolk. In addition to the comparative study between the experimental and control eggs, experiments were conducted to determine the effects of heating on the phospholipid profile and the comparative molar ratios of cholesterol and total phospholipid. The phospholipid composition determined for frozen egg yolk samples showed no differences for the major components of phosphatidylcholine and phosphatidylethanolamine between the control and experimental diet group.

A possible nonspecific site of action of amiodarone on newborn rat heart cell in culture.

Amiodarone and its major metabolite desethylamiodarone are potent antiarrhythmic drugs that have multiple pharmacological effects on the heart. We examined the effect of both drugs on the neonatal rat heart monolayer cell culture. The cells were stimulated with L-arterenol (10(-7) M) and choleratoxin (1.

Evidence for the presence of fatty acid binding protein in avian granulosa cells.

The existence of fatty acid binding protein in chicken ovarian granulosa cells was investigated using a fluorescent assay based on the ability of cis-parinaric acid to fluoresce as a result of its interaction with proteins. Cytosolic fractions were prepared from granulosa cells obtained from the first (F1), second (F2), and third (F3) largest preovulatory follicles as well as from a pool of small yellow follicles of the chicken ovary, and each fraction was incubated with different concentrations of cis-parinaric acid. Total fluorescence increased (but fluorescence per milligram protein decreased) as the quantity of cytosolic protein from all follicle types was increased.

Sterol domains in phospholipid membranes: dehydroergosterol polarization measures molecular sterol transfer.

The domain structure of cholesterol in membranes and factors affecting it are not well understood. A method, based on kinetics of delta 5,7,9,(11),22-erogostatetraen-3 beta-ol (dehydroergosterol) fluorescence polarization change and not requiring separation of donor and acceptor membranes, was used to examine sterol domains in three-component cholesterol:dehydroergosterol:phospholipid small unilamellar vesicles (SUV). A new mathematical data treatment was developed to provide a direct correlation between molecular sterol exchange and steady-state dehydroergosterol fluorescence polarization measurements.