Triacylglycerol hydrolysis by cells isolated from lactating rat mammary gland.

The hydrolysis of exogenous trioleoylglycerol emulsions by suspensions of cells prepared from lactating rat mammary gland has been investigated. Cell integrity remains high throughout short (at least 30 min) incubations, during which extracellular hydrolysis of trioleoylglycerol proceeds at a mean rate (11 preparations) of 1.9 nmol oleate (and 0.

Regulation of adipocyte insulin receptor number and metabolism during late-pregnancy.

The regulation of the rate of fatty acid synthesis of rat adipose tissue during late-pregnancy has been investigated. Rats at day 18 of pregnancy were injected over a 2-day period with either prostaglandin F2 alpha (PGF2 alpha), PGF2 alpha plus progesterone, PGF2 alpha plus bromocriptine or carrier solutions, and were then killed on day 20 of pregnancy. Injections of PGF2 alpha resulted in a decreased rate of fatty acid synthesis, a lower serum-insulin concentration, and a reduced number of insulin receptors of adipocytes.

Effects of ascorbic acid, vitamin E, and fatty acids on lipid composition in cockerels.

Serum, aorta, heart, and liver tissues of cockerels reflected numerous changes in cholesterol and triglyceride composition when 5 or 10% oleic or palmitic acid, ascorbic acid, and vitamin E were added to their diets. Heart cholesterol concentration and liver cholesteryl ester content increased with the 10% oleic acid diet. Heart and liver cholesterol increased when ascorbic acid was added to 5% fatty acid diets, and heart cholesterol increased when ascorbic acid was added to the 10% palmitic acid diet.

Homografts in tympanoplasty: will they be a disaster? an experimental study.

Experimentally transposed homograft ossicles in rats showed behaviour less stables than autografts, all being resorbed within 48 weeks. Using information derived from this and other experimental work in both animals and humans it is predicted that homografts will be unstable in humans in the long term.

Activation of milk lipase by serum proteins: possible role in the occurrence of lipolysis in raw bovine milk.

The increase in unesterified fatty acid content of unpasteurized bulk milk in storage at 4 degrees C in the presence of known effectors of bovine milk lipoprotein lipase originating from bovine serum was studied. Bovine serum and high density lipoprotein (HDL) caused an increase in developed unesterified fatty acid levels whilst lipoprotein-free serum, apo-HDL, all individual apo-HDL tested, and the unfractionated C-peptide fraction were without lipolytic effect. In the presence of HDL-lipids, 2 C-peptides stimulated considerable lipolysis, as did the combination of HDL-lipid with unfractionated C-peptides.

Role of insulin receptors in the changing metabolism of adipose tissue during pregnancy and lactation in the rat.

Changes in the volume, the rates of fatty acid synthesis and synthesis of the glycerol moiety of acylglycerols, the activity of lipoprotein lipase, and the number and affinity of insulin receptors of adipocytes, and concentrations of serum insulin, prolactin and progesterone were determined in virgin rats and in rats at various stages of pregnancy and lactation. Changes in the metabolic activities of adipose tissue appeared to be synchronized and primarily comprised a marked decrease in anabolic activity around parturition. In contrast, the number of insulin receptors (Kd 1.

Binding of 4-methylumbelliferyl alpha-D-mannopyranoside to tetrameric concanavalin A Fluorescence temperature-jump relaxation study.

The kinetics of saccharide binding to the treatment form of concanavalin A have been studies at pH 7.2 with the temperature-jump method. 4-Methylumbelliferyl alpha-D-mannopyranoside was used as a ligand; its fluorescence is totally quenched upon binding.

Effects of ascorbic acid and vitamin E on serum lipids of cockerels fed Wesson oil-cholesterol diets.

The major lipid changes caused by adding 5% Wesson Oil and 1% cholesterol to cockerel diets were large increases in serum cholesterol, cholesteryl esters, and triglycerides. Lecithin and cephalin were not affected. Ascorbic acid significantly increased serum triglycerides; vitamin E significantly lowered serum cholesterol.