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Biomedical subjects

A Ia Mestechkina

Publications and source records attributed to A Ia Mestechkina.

15 recordsLinked to original sources

[Peptide hydrolase activity during embryonic carp development].

It was established that in the carp the process of embryonic and early postembryonic development was accompanied by the increase in the activity of both the trypsin- and chemotrypsin-like peptide hydrolases. This increase is most evident in larvae with resorbing yolk. The total and protein nitrogen content suffers no changes during embryonic and early postembryonic development. The content of non-protein nitrogen increases from the stage of the middle of segmentation on attaining the maximum level in larvae with resorbing yolk.

Animals↗

[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. A single ACTH administration to the intact rabbits was accompanied by increase in the enzyme activity in the liver and the spleen, whereas to the adrenalectomized animals--in the brain, muscles and the blood plasma. A repeated administration of both hormones decreased the enzyme activity in the brain and the liver.

Adrenalectomy↗

[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.

Adrenocorticotropic Hormone↗

[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. Hydrocortisone and ACTH administration cause an increase in the acid peptide-hydrolase activity in MLF and its decrease in the brain soluble and microsomal fractions of adrenalectomized rabbits. The degree of solubilization of MLF acid and neutral peptide-hydrolase by detergent triton X-100 after adrenalectomy is increased. Hydrocortisone and ACTH administration, on the contrary, decrease a degree of solubilization of the brain MLF peptide-hydrolase in adrenalectomized animals.

Adrenalectomy↗

[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.

Adrenalectomy↗

[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. Parallel with that AsT and AlT activities are decreased in the spleen tissue. Multiple administration of hydrocortisone induces analogous changes in the AsT activity in the muscle and in the AlT activity in the liver, muscle and blood plasma. A single administration of ACTH induces an increase of the AsT activity in the muscle supernatant and in blood plasma. It also causes a rise of the AlT activity in the liver, muscle supernatant and blood plasma. The AlT activity is decreased in the brain supernatant. A question about stability of free amino acids metabolism (especially of alanine and aspartic acid) in the rabbit brain with changes in corticosteroid levels of organism is under discussion.

Adrenal Glands↗