[Study of osteoprotective and hypolipidemic effects of estrogen 8α-analogues].

The aim of this work was to study the ability of some estrogen 8α-analogues, that have CH3-group in the C-3 position, exhibit osteoprotective and cholesterolemic effects. The properties of these analogues was comparisoned with effects of native estradiol and 17α-ethynylestradiol (EE). We showed that compounds 3 ((d,l)-17ß-acethoxy-3-methoxy-8α-estra-1,3,5(10)-triene) and 4 ((d,l)-3-methoxy-8α-estra-1,3,5(10)-triene-17-one) had the same osteoprotective and cholesterolemic effects as EE. The utherotropic effects of compound 3 and EE were the same, while the utherotropic activity of 17-keto derivative (compound 4) was higher than effect of EE. The osteoprotective and cholesterolemic effects of compounds 5 and 6 (d- or l-17ß-acethoxy-3-methoxy-13-ethyl-8α-gone-1,3,5(10)-triene) were approximately the same, however the utherotropic action of these compounds was different: the compound 5 had significantly lower activity, but the compound 6 had the same effect in comparison with EE. Thus, all studied estrogen 8α-analogues may be used as basic constructions for structural modifications which is necessary as medications with while spectrum of biological properties.

[Cardiovascular system reactions and bioenergy metabolism in relation to adaptation to apnea]. / Reaktsii serdechno-sosudistoi sistemy i bioénergeticheskii metabolizm v sviazi s adaptatsiei k apnoé.

Responses of the cardio-vascular system and bioenergetic metabolism were studied in the heart tissue in apnoea in naturally adapted to diving musk-rats and unadapted rats and mice. A sharp bradycardia was shown to develop in former animals in arresting a breathing as well an increase in the neutrophils contents in the blood. The data obtained suggest that release of the necessary oxygen and antiradical defence functions can be related to the catalase activity.

[Effect of thyrotoxicosis on lipid fatty acid composition in various subcellular fractions of the rat brain]. / Deistvie tireotoksikoza na zhirnokislotnyi sostav lipidov razlichnykhsubkletochnykh fraktsii golovnogo mozga krys.

Thyrotoxicosis, which developed after subcutaneous administration of L-thyroxin at a dose of 400 micrograms/100 g of body mass, was accompanied by distinct alteration of fatty acid composition in lipids of adult rat brain myelin, synaptosomes, mitochondria and microsomes. The most significant alterations were detected in synaptosomes and mitochondria. Under conditions of thyrotoxicosis the ratio of polyunsaturated docosahexaenic and docosatetraenic acids was decreased in synaptosome lipids, whereas the content of palmitic, oleic and neuronic acids was increased. The ratio of unsaturated arachidonic and docosahexaenic fatty acids was increased but content of palmitic and linoleic acids was decreased in mitochondrial lipids.

[Change in the tricarboxylic acid cycle dehydrogenase activity under the action of thyroxine in the brain of animals of varying age]. / Izmenenie aktivnosti degidrogenaz tsikla trikarbonovykh kislot pod deistviem tiroksina v mozge zhivotnykh raznogo vozrasta.

The effect of thyroxin on the activities of tricarboxylic acid cycle enzymes and NADP-malate dehydrogenase in the rat brain was studied. Experiments were conducted on 20- and 40-day old and on adult rats. Injection of L-thyroxin (50 microgram/100 g body weight) to thyroidectomized rats induced some changes in the activities of citrate-syntase, dehydrogeases of TAC and malic enzymes in the mitochondrial and cytoplasmic fractions of the brain. The most significant effect of the hormone was found in the brain of 20-day old rats there was an increase of the enzyme activities by 40--60%. The effect of the hormone on the enzymes activities could be prevented by simultaneous administration of actinomycin D (10 microgram intracerebrally). This fact indicates that the main mechanism in increasing the enzymic activity lies, probably, in stimulation of the enzyme biosynthesis by the hormone.

[Participation of glutamate and alanine in amino acid biosynthesis, in lipogenesis, and in gluconeogenesis in the brain]. / Uchastie glutamata i alanina v biosinteze aminokislot, v lipogeneze i gliukoneogeneze golovnogo mozga.

The participation of glutamate and alanine in lipogenesis and gluconeogenesis of brain was investigated. 5(14)C glutamate was injected intracisternally in an amount of 5 mcCu/l g tissue and 3(14)C-alanine was injected subcutaneously 30 mcCu/100 g body weight. Labels from glutamate and alanine were recovered in different lipid franctions -- in phospholipids, glycerides, free fatty acids and cholesterol, as well as in glucose and glycogen. An intensive incorporation of label from 5(14)C glutamate into various amino acids--aspartic acid, glutamine, serine, glycine and alanine--was demonstrated. The data presented indicate the participation of amino acids in lipogenesis and gluconeogenesis of brain.