[Effect of insulin on the composition of chromatin phospholipid in rat liver cells].

In vivo the action of insulin on rat liver chromatin phospholipid composition was investigated. It was shown that the hormone led to reliable increase (nearly 20%) of total phospholipid content. The same phenomenon was shown also in the fraction of active chromatin while the phospholipids content of non-active chromatin didn't changed.

[Shifts in phospholipid composition of the nuclear matrix in rat liver cells exposed to insulin].

It was shown that the total content of phospholipids of rat liver nuclear matrix increased after in vivo action of insulin (2 units per 100 g of animal weight). At the same time the sphyngomyelin content was increased and the content of phosphatydilcholine and phoshpatydilinositol was decreased significantly under the hormone action. The decreasing of monophosphoinositides amount was accompanied by the increasing of triphosphoinositides content which indicates the redistribution among the phosphoinositides fractions under the hormone action and may be the result of insulin initiation of phosphoinositide pathway in nuclear membrances.

[Effect of hydrocortisone on composition of polyphosphoinositides in liver cell nuclear membrane and rat brain].

The action of hydrocortisone in vivo was shown to cause changes both in the total amount of phospholipids and polyphosphoinositides of rat liver and brain nuclear membranes. The hormone increased the content of five from seven phospholipid fractions including the fraction of monophosphoinositide when acting in concentration and exposition leading to activation of biosynthetic processes. The increasing of monophosphoinositides amount was accompanied by the decreasing of triphosphoinositides content which indicated the redistribution among the phosphoinositides fractions under the steroid hormone action in both cell types.

[Effect of estradiol on phosphoinositide composition of nuclear membranes of rat brain cells].

The effect of estradiol on phospholipids and particularly on phosphoinositides of nuclear membranes of rat brain cells at different stages of hormone action was investigated. It was shown that hormone leads to the elevation of phospholipids total amount at the primary and early stages of its action (1 and 4 h after estradiol injection, correspondingly). The increase of content of almost all individual fractions of phospholipids as well as phosphatidylinositol (i.

[An increase of CDP-choline: diglyceride phosphocholine transferase reaction in microsome fraction and its decrease in nuclear membranes of the rat liver after treatment with hydrocortisone].

The availability of CDP-choline: diaglyceride phosphocholine transpherase activity in the rat liver nuclear membrane fraction is shown. It is established that the enzyme activity in nuclear membrane fraction makes up less than 1/3 of the analogous activity in microsomes. The hydrocortisone treatment of animals leads to an increase of the enzyme activity in microsomes and to a decrease in the nuclear membranes.

[Action of hydrocortisone on the lipid composition of active and inactive chromatin fractions in the rat liver].

A composition of phospholipids and neutral lipids of rat liver chromatin and its active and inactive fractions has been investigated. It is shown that the hydrocortisone action results in marked increase in phospholipid/neutral lipid ratio of both chromatin and its active fraction. The changes in lipid content is clearly expressed in active chromatin fraction, the lipid content of inactive fraction is not changed.

[Neutral lipids of nuclear membranes and chromatin in rat liver after hydrocortisone administration].

It is shown that over 80% of nuclear neutral lipids are found in the nuclear membrane preparations, whereas only 7%--in chromatin. The injection of hydrocortisone to animals significantly decreases the neutral lipids content in both fractions. These results and the data obtained previously by the authors indicate the possible participation of nuclear membrane and chromatin lipids in the process of hormonal regulation of the genetic activity.

[Lipid composition of the rat liver nuclear matrix as affected by hydrocortisone].

It has been found that the rat liver nuclear matrix contains a small amount of phospholipids (2%) and neutral lipids (1.6%). The injection of hydrocortisone increased the nuclear matrix phospholipid content and reduced its neutral lipid levels.

[Effect of hydrocortisone on the phospholipid composition and activity of various enzymes of phospholipid metabolism in the nuclear membranes of the rat liver].

It was shown that hydrocortisone injections markedly increase the total content of liver nuclear membrane phospholipids, the greatest increase being observed in the phosphatidyl choline level. It was found also that nuclear membranes contain phospholipid metabolism enzymes. The hormone-induced increase in the phospholipid content is accompanied by a marked decrease of the activity of phospholipase A2 (5.

[Changes in the phospholipid composition of rat liver chromatin during treatment with hydrocortisone].

When isolating protein components of chromatin from the rat liver phospholipids are found in the fraction of nonhistone proteins but not in that of histone. Administration of hydrocortisone to animals evokes a reliable increase of the phospholipids of hydrocortisone to animals evokes a reliable increase of the phospholipids amount in the preparations of chromatin and labile-bound nonhistone proteins. In this case the fraction of phosphatidylcholine lowers considerably with a simultaneous increase of sphingomyelin and phosphatidylethanolamine.