RESUMEN
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.
Asunto(s)
Insulina/farmacología , Hígado/metabolismo , Matriz Nuclear/metabolismo , Fosfolípidos/metabolismo , Animales , Hígado/efectos de los fármacos , Matriz Nuclear/efectos de los fármacos , RatasRESUMEN
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. It was also shown that the content of three from six phospholipid fractions altered under the insulin action. The content of sphingomyelin and phosphatidilethanolamine increased and the quantity of phosphatidylinositol decreased under the hormone action. The decrease of monophosphoinositides content was accompanied by the reliable increase of triphosphoinositides amount. It was suggested that the fractions of chromatin polyphosphoinositides were redistributed under the action of insulin.
Asunto(s)
Cromatina/metabolismo , Hepatocitos/efectos de los fármacos , Insulina/farmacología , Fosfolípidos/metabolismo , Animales , Hepatocitos/metabolismo , RatasRESUMEN
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.
Asunto(s)
Encéfalo/efectos de los fármacos , Hidrocortisona/farmacología , Hígado/efectos de los fármacos , Membrana Nuclear/efectos de los fármacos , Fosfatos de Fosfatidilinositol/metabolismo , Animales , Encéfalo/metabolismo , Hígado/metabolismo , Membrana Nuclear/metabolismo , Fosfatos de Fosfatidilinositol/biosíntesis , RatasRESUMEN
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.e. monophosphoinositide) was detected. It is remarkable that the monophosphoinositides elevation takes place mainly due to the decrease of di- and especially of triphosphoinositide. The ratio of triphosphoinositide/monophosphoinositide decreases more than twice. It was concluded that the ratio of triphosphoinositide to monophosphoinositide may be a peculiar indicator of the status of nuclear membranes for the functioning of triphosphoinositide regulatory system.
Asunto(s)
Encéfalo/efectos de los fármacos , Estradiol/farmacología , Membranas Intracelulares/efectos de los fármacos , Fosfatidilinositoles/metabolismo , Fosfolípidos/metabolismo , Animales , Encéfalo/metabolismo , Encéfalo/ultraestructura , Femenino , Membranas Intracelulares/metabolismo , RatasRESUMEN
The in vivo action of estradiol was shown to cause changes both in the total amount of phosphoinsitides and their individual fractions of rat synaptosomes. The maximum elevated levels of phosphoinositides was revealed on 1-hour exposure to the hormone. It is suggested the redistribution of phosphoinositides at the primary stage (1 hour postinjection) of exposure may rely on the initiation and functioning of the phosphoinositide mechanism, the ratio of triphosphoinositide to monophosphoinositide may be a peculiar indicator of the status of synaptosomal membranes for the functioning of this regulatory system.
Asunto(s)
Encéfalo/efectos de los fármacos , Estradiol/farmacología , Fosfatidilinositoles/metabolismo , Sinaptosomas/efectos de los fármacos , Animales , Encéfalo/metabolismo , Cromatografía en Capa Delgada , Femenino , Embarazo , Ratas , Sinaptosomas/metabolismoRESUMEN
Spermine decreased distinctly the activity of Ca2+ -phospholipid-dependent protein kinases, whereas not affected the protein kinase A activity. Content of cytosol estradiol receptors was drastically decreased in rat uterine in presence of the polyamine. The data obtained and literature data suggest that activation of estradiol receptors appears to occur after phosphorylation by means of Ca2+ - dependent protein kinases, which are regulated via phosphoinositide-involving mechanism, i.e. these receptors acquire the ability to bind hormones.