[Liver mitochondrial phospholipase activation in hyperthyroid rabbits]. / Aktivatsiia fosfolipazy mitokhondrii pecheni krolikov pri gipertireoze.

Mitochondria obtained from hyperthyroid rabbit liver contained an approximately 4-fold greater amount of free fatty acids (FFA) than preparations from the control animals. The temperature dependence of FFA accumulation (29--38 degrees C) showed that the activation energy of mitochondrial lipid hydrolysis for control and experimental animals was 7 kcal/mole and 29 kcal/mole, respectively. The mitochondria were kept at 3 degrees C for 48 h. During this period there was an accumulation of fatty acids. The rate of the process in the mitochondria of hyperthyroid animals was several times than that in the control ones. This indicates the activation of mitochondrial phospholipase by the liver in hyperthyrosis. The increased mitochondrial phospholipase activity seen in hyperthyrosis is assumed to be determined by changes in the physical properties of lipid membranes.

[Accumulation of lipid peroxidation products and suppression of the retinal electrical activity of vitamin E deficient rats exposed to high intensity light]. / Nakoplenie produktov perekisnogo okisleniia lipidov i podavlenie élektricheskoi aktivnosti setchatki E-avitaminoznykh krys pri deistvii sveta vysokoi intensivnosti.

Induction of alimentary vitamin E deficiency in rats is accompanied by accumulation of lipid peroxidation products in the retina in vivo and by reduction of the magnitude of electroretinogram waves. Photodamage to the retina caused by the action of light of high intensity (10 000 lx for 3.5 h) is more pronounced in vitamin E deficient animals than in control rats fed standard laboratory chow. The exposure of rats to the light of high intensity results in accumulation of lipid peroxides, the magnitude of which is far greater in vitamin E deficient animals than in controls. The photodamage process is reversible and by the end of the 14th day after exposure to light the content of lipid peroxidation products in the retina and its electric activity are close to the values found in controls.

[Determination of phospholipase A2 activity in liver mitochondria using fluorescent dye 1,8-anilinonaphthalene sulfonate]. / Opredelenie aktivnosti fosfolipazy A2 v mitokhondriiakh pecheni s pomoshch'iu fliuorestsentnogo krasitelia 1,8-anilinonaftalin sul'fonata.

Quantitative estimation of free fatty acids was carried out in liver mitochondria of normal and thyroidectomized rabbits by means of two procedures--spectrophotometry using rhodamine 6Zh and a fluorescent method with 1,8-aniline naphthalene sulfonate /ANS/ as a dye. The use of ANS enabled to estimate quantitatively the free fatty acids beginning from 25 nmol in a sample /with eggor of about 17%/ by visual evaluation of the spot areas. As compared with the rhodamine procedure, use of ANS permitted to increase 5-fold the sensitivity of free fatty acid estimation, to elevate 6-fold the accuracy of the analysis, to overcome the step of fatty acid elution from chromatogramms and to decrease the time required for analysis. The data obtained suggest that the hyperthyroid state in rabbits was accompanied by an increase in the phospholipase A2 activity in liver mitochondria.

[Mathematical model of the dose-time-effect relationship in the intramuscular administration of testosterone esters]. / Matematicheskaia model' zavisimosti doza-vremia-éffekt pri vnutrimyshechnom vvedenii éfirov testosterona.

Two equations of the dose-time-effect dependence during repeated intramuscular injections of testosterone esters are presented. The equation coefficients characterizing both properties of the drugs injected and individual features of the organs exposed to their action are interpreted. Moreover, two equations for calculating duration of the mitotic cycle of the test organ cells are given.

[2 possible mechanisms of action of thyroxine on mitochondrial swelling]. / Dva vozmozhnykh mekhanizma deistviia tiroksina na nabukhanie mitokhondrii.

The effect of thyroxin on different types of mitochondrial swelling (induced by calcium, detergents, valinomycine, or lipid peroxidation) was investigated. Under conditions favourable for phospholipase-induced mitochondrial swelling on account of phospholipase activation (low Mg2+ concentration, and Ca2+ present in the incubation medium) the hormone proved to accelerate the swelling of the organellae. When phospholipase-induced mechanism of mitochondrial swelling was inhibited (high Mg2+ concentration) thyroxin depressed considerably the swelling of organellae induced by lipid peroxidation due to its antioxidant action.

[Influence of thyroxine on lipid peroxidation in mitochondrial membranes]. / Deistvie tiroksina na perekisnoe okislenie lipidov v membranakh mitokhondrii

In concentrations above 5.10(-7) M thyroxin brought about a delay in chemifluorescence development and decreased the slope of semilogarythmic plot of chemifluorescence curve at the initial step of the fluorescence slow flash. The antioxidant activity of thyroxin was found to be insignificantly lower than that of the well-known antioxidant alpha-tocopherol. In lower concentrations (about 1.10(-8) M) the hormone can act as prooxidant, the effect being the highest in the case of intact mitochondria incubated in the phosphate-containing medium in the presence of Mg2+ ions, and much less in the mitochondria treated in hypotonic medium containing Ca2+ ions.

[Quantitative evaluation of the dose-response relationship after intramuscular administration of testosterone and its esters]. / Kolichestvennaia otsenka zavisimosti doza-effekt pri vnutrimyshechnom vvedenii testosterona i ego efirov.

Experiments were conducted on rats. A study was made of the reaction of target organs to the intramuscular injection of androgenic preparations--testosterone and its esters (acetate, propionate, phenylpropionate, isocapronate, enantate and caprinate) comparison with anabolic methylandrostendiol. An equation is presented for mathematical description of the dependence of the androgenic effect on the dose of the praparations injected, used in a wide range of doses. The equation coefficients proved to have a definite physiological sense.

[Evaluation of the skin resorptive action of testosterone and its esters]. / K otsenke kozhno-rezorbtivnogo deistviia testosterona i ego éfirov

The skin-resorptive action of testosterone and of its ethers (propionate, phenylpropionate, isocapronate, enantate, caprinate) was studied on castrated albino male rats with a one-time application to the skin. The effect was assessed by the growth of the seminal vesicles and the ventral lobe of the prostate. The highest skin-resorptive activity displayed testosterone-propionate and the lowest--testosterone-caprinate. The maximum effect following application of all the studied substances was registered on the 2-3d day. The amount of the maximum active dose (0,1 mg per animal) warrants including these compounds in a group of highly dangerous substances producing a skin-resorptive action.