[Aspartate and alanine aminotransferase activity in the tissues of adrenalectomized rabbits following administration of hydrocortisone and corticotropin].

Aspartate and alanine aminotransferase (AsT, AlT) activities were studied in tissues of adrenalectomized rabbits which were treated with a single and multiple administrations of hydrocortisone (5 mg/kg) or a single administration of corticotropine (ACTH, 10 units/kg). It is shown that adrenalectomy decreases the AsT activity in homogenate of femoral muscle tissue and decreases the AlT activity in homogenate and supernatant of the liver, spleen and muscle tissue and in blood plasma. A single administration of hydrocortisone increases the AsT activity in supernatant of femoral muscle tissue and in blood plasma and increases AIT activity in the brain, liver, muscle and blood plasma.

[Content of free amino acids in rabbit tissues as affected by adrenalectomy and administration of hydrocortisone and ACTH].

Adrenalectomy is accompanied by a decreased content of free amino acids in muscules and blood plasma by an increased content of certain amino acids in the liver. A single injection of hydrocortisone to adrenalectomized animals increases the content of amino acids in muscles and lowers their total content in the liver; a single injection of ACTH lowers the total content of amino acids in the liver and blood plasma "Substitutive therapy" by hydrocortisone essentially increases the content of amino acids in the liver, muscles and blood plasma. Under conditions of the experiment the least changes in the content of amino acids were found in the brain tissue.

[Peptide hydrolase activity in rabbit brain subcellular fractions under conditions of adrenalectomy and administration of hydrocortisone and ACTH].

Adrenalectomy and administration of hydrocortisone and ACTH are shown to induce no changes in the total activity of neutral peptide-hydrolase in both homogenates and brain subcellular fractions. The absence of adrenalectomy and hormone administration effect on the total peptide-hydrolase activity in homogenates is established simultaneously with its essential changes in the brain subcellular fractions. A decrease in the enzymic activity of the mitochondrial-lysosomal fraction (MLF) following adrenalectomy is observed side by side with its increase in a soluble fraction.

[Changes in alanine and aspartate aminotransferase activity in rabbit tissues following administration of hydrocortisone and ACTH].

Hydrocortisone and ACTH administration induced AlT- and AsT-activity changes in the brain hemispheres, liver, spleen, muscles and blood plasm of rabbits. The direction and rate of changes of the studied enzymes activity in the tissues was not the same after hydrocortisone and ACTH injections and depended on duration of the hormones administration. The changes in the AlT-activity were more essential than those in the AsT-activity for all tissues.

[Change in the activity of tyrosine aminotransferase in the tissues of rabbits with various levels of corticosteroids in the body].

Experiments were conducted on rabbits. As revealed, hypocoriticism was accompanied by a reduction of the tyrosineaminotranspherase in the liver, muscles and blood plasma; the enzyme activity was unchanged in the brain and the spleen. An increase of the corticosteroid level in the organism after the administration of hydrocortisone to the intact and adrenalectomized animals led to increase of the enzyme activity in the tissues under study; the effect of hydrocortisone action depended on the initial hormonal background in the organism and the duration of the hormone administration.