SummaryThe lipids of ovina liver and plasma have been separated by silicic acid chromatography into cholesterol ester, triglyceride, free fatty acid, and phospholipid fractions. Fatty acid constituents of these fractions have been determined by gas chromatography. The lipid content of these tissues was also determined for animals subjected to a prolonged protein depletion. Several significant differences were caused by the experimental diet, with the liver showing more alterations than plasma. The unsaturated C 18 fatty acids were affected to the greatest degree.Implications of these results have been discussed in relation to comparative biochemistry and intermediary lipid metabolism.

In order to elucidate the alterations in tissue function of Merino sheep feeding on a low protein, low energy diet, the sequential measurement of a number of clinical parameters has been performed. Emphasis has been directed to the protein storage tissues, and the following indices were measured: bromsulphthalein clearance; serum levels of glutamic oxalacetic transaminase, glutamic pyruvic transaminase, total cholesterol, cholesterol esters, total proteins, electrophoretic protein fractions, and urea; urinary volume, and urine creatine, creatinine, and urea. Alterations in these indices were consistent with a marked degree of liver dysfunction occurring after several weeks on the experimental diet. No significant changes were apparent in the functional ability of kidney or muscle.

Natural actomyosin, actin and myosin, have been pressurized at up to 150 MN/m2 for 1 h at O°C and examined 3-5 h later.Pressurization of myosin resulted in the formation of aggregates with a molecular weight approximately that expected for a dimer, whereas with F-actin depolymerization occurred. With actomyosin, a gel to sol transition was promoted. Viscosity and light-scattering measurements indicated that pressurization results in a large measure of disaggregation of actomyosin in solution.Pressurization of actomyosin resulted in a greater decrease in the calcium-sensitive, than in the calcium-independent, Mg2+ ATPase activity. The Ca 2 + and K+-EDTA ATPase activities of myosin were inhibited to about the same extent.

SummaryThe glutamate transaminase activity of sheep tissues has been s~udied, along with the effect of such variables as age, sex, breed, and nutritional status of the animal. A wide range of normal activities has been found, with glutamic-oxaloacetic transaminase always more active than glutamic-pyruvic transaminase.Most activity centres in heart muscle, liver, kidney, and skeletal muscle; there appear to be sex and age differences, but little variation between breeds.Prolonged protein depletion has been shown to result in significant alterations of tissue transaminase activity, not only in the liver but also in myocardium, skeletal muscle, spleen, and pancreas. In addition, a cofactor deficiency was caused by the experimental diet.The implications of these findings have been discussed, in relation both to intermediary metabolism and to chemical pathology.