RESUMEN
A high sensitivity towards cycloheximide is shown for three main protein fractions of albino rat skeletal muscle, i. e. a 50% inhibition of myofibrillar protein synthesis is caused by a dose of 0.1 mg/100 g of body weight after 3.5 h, the rate of inhibition of two other fractions is even higher. A dose of 3.0 mg/100 g of body weight inhibits the synthesis of the sarcoplasmic and myofibrillar proteins by 96% by the end of the 15th minute. Administration of cycloheximide in vivo (0.3 mg/100 g of body weight) inhibits the alpha-amanitin-resistant DNA-dependent RNA-polymerase activity of the nuclei. The relation between the inhibition rate and time of the cycloheximide action is ruled by the first order kinetic. This allows postulating the existence of a fast renewal with a period of half-life of about 110 min (determined graphically) among nuclear proteins involved in the transcription of rRNA. The idea of this protein participation in adaptive shifts of rRNA synthesis in the systematic skeletal muscle function is suggested.
Asunto(s)
Cicloheximida/farmacología , ARN Polimerasas Dirigidas por ADN/metabolismo , Proteínas Musculares/biosíntesis , Animales , Miofibrillas/efectos de los fármacos , Miofibrillas/metabolismo , ARN Polimerasa I/antagonistas & inhibidores , Ratas , Transcripción Genética/efectos de los fármacosRESUMEN
The activity of hexokinase and lipase has been determined in skeletal muscles of different metabolic types and adipose tissue of untrained albino rats during two variations of predominant aerobic physical exercise: long-term swimming and long-term swimming including short-term loads (20 s) of maximal intensity (acceleration). Muscle and liver glycogen depletion, serum lactate, glucose and free fatty acids concentrations are also investigated. It is shown that long-term swimming (first variation) has promoted a decrease of both enzymatic activities in muscle fibres and an increase in lipolytic activity of the adipose tissue. During the physical exercise with the acceleration an increase in hexokinase activity occurs in response to 20 min swimming, with its maximal decrease in response to 40 min of exercise. Activity of lipase in slow-twitch oxidative fibres of soleus and in the adipose tissue increases from 20 min to the end of the exercise. Depletion of glycogen in the muscles and liver is determined in fast-twitch oxidative-glycolytic fibres and in the liver in two types of exercises, being more significant in muscles after exercise with accelerations. Concentrations of serum lactate, glucose and free fatty acids remain unchanged after both variations of swimming. So, it may be concluded that acute adaptation to the predominant aerobic physical exercise with activity under short-term loads of maximal intensity has induced a rise of the capacity of oxidative muscles to utilise endogenous and exogenous carbohydrate and lipid reserves.
Asunto(s)
Metabolismo de los Hidratos de Carbono , Metabolismo de los Lípidos , Músculos/fisiología , Esfuerzo Físico , Tejido Adiposo/enzimología , Animales , Ácidos Grasos/metabolismo , Glucosa/metabolismo , Glucógeno/metabolismo , Hexoquinasa/metabolismo , Lactatos/sangre , Lipasa/metabolismo , Masculino , Músculos/enzimología , Músculos/metabolismo , RatasRESUMEN
Lipase activity was studied in preparations of skeletal muscles and fatty tissue by means of measurement of oleic acid methyl ester concentration developed after triolein hydrolysis using gas-liquid chromatography apparatus. The procedure described helped unify the methodology approaches in estimation of tissue lipases activity and of free fatty acid spectrum of blood serum in microquantities of the material studied, it exhibited high sensitivity and specificity.
Asunto(s)
Cromatografía de Gases/métodos , Lipasa/metabolismo , Tejido Adiposo/enzimología , Animales , Ácidos Grasos no Esterificados/sangre , Hidrólisis , Masculino , Músculo Esquelético/enzimología , Ratas , Trioleína/metabolismoRESUMEN
Correlations were identified between tumor morphobiochemical characteristics and basic parameters of reproductive homeostasis in 256 cases of endometrial carcinoma. A correlation was established between the levels of cytoplasmic receptors to estradiol (ER) and progesterone (PR), on the one hand, and morphological differentiation and spontaneous secretion in tumor tissue, on the other. A direct correlation was found between ER and metastatic spread to regional lymph nodes, and no correlation--between ER and PR and major parameters of reproductive homeostasis. A significant decrease in ER, PR, gonadotropins, estradiol and colpocytological reaction indexes followed hormone therapy with hydroxyprogesterone capronate and medroxyprogesterone acetate. The criteria of endometrial carcinoma patients sensitivity to progestin therapy were as follows: ER and PR levels--more than 30.0 fmol/mg protein, estradiol--more than 30-50 pg/ml and colpocytological index--over 40%.
Asunto(s)
Antineoplásicos/uso terapéutico , Citoplasma/efectos de los fármacos , Hidroxiprogesteronas/uso terapéutico , Medroxiprogesterona/análogos & derivados , Receptores de Superficie Celular/efectos de los fármacos , Neoplasias Uterinas/tratamiento farmacológico , Caproato de 17 alfa-Hidroxiprogesterona , Citoplasma/análisis , Evaluación de Medicamentos , Femenino , Homeostasis/efectos de los fármacos , Humanos , Metástasis Linfática , Medroxiprogesterona/uso terapéutico , Acetato de Medroxiprogesterona , Persona de Mediana Edad , Cuidados Preoperatorios , Receptores de Superficie Celular/análisis , Reproducción/efectos de los fármacos , Neoplasias Uterinas/análisis , Frotis VaginalRESUMEN
A comparative investigation into the influence of 3 and 5 times a day feeding on the protein metabolism in the skeletal muscles and liver of albino rats was carried out. The dietary regimen with a greater frequency of feeding was found to be consonant with a higher concentration of total aminonitrogen and with a number of essential amino acids, as well as with a higer activity of asparate-aminotransferase in the study tissues. Along with this, there occurs a more intensive incorporation of radioactive leucine in the total proteins and basic proteinic fractions of the skeletal muscles and also augments specific radioactivity of the poly-A-containing informative RNA in polysomes and is in evidence shifting the ribosomal spectrum toward formation of polysomal complexes. The activation of proteinosynthesis observed with increasing frequency of feeding may be ascribed to a more uniform diurnal supply of nutrients to the organism.
Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Proteínas en la Dieta/metabolismo , Hígado/metabolismo , Músculos/metabolismo , Aminoácidos/metabolismo , Animales , Leucina/metabolismo , Masculino , Proteínas Musculares/metabolismo , Ácido Orótico/metabolismo , Biosíntesis de Proteínas , ARN/metabolismo , Ratas , Factores de TiempoRESUMEN
A study was made of 3H-19-nortestosterone binding by isolated nuclei and 0.4 M KCl nuclear extract of the rat skeletal muscle. Binding specificity was ascertained by incubation in the presence of various unlabeled steroids. The Kd values were measured for nuclei and 0.4 M KCl nuclear extract (11.6 +/- 2.5 nM and 9.9 +/- 1.6 nM, respectively). The amount of binding sites was 24.1 +/- 1.7 fmol/mg DNA or 13.7 +/- 1.0 fmol/g tissue. Enzymatic treatment with pronase and DNase shows that nuclear androgen receptors are proteins. DNA was noted to have a stabilizing effect. DNase treatment of nuclei during extraction with 0.4 M KCl was shown to significantly increase the amount of specifically bound radioactivity in the extract.
Asunto(s)
Andrógenos/metabolismo , Núcleo Celular/metabolismo , Músculos/metabolismo , Animales , Masculino , Nandrolona/metabolismo , Ratas , Receptores Androgénicos/metabolismo , Temperatura , Testosterona/metabolismo , Factores de TiempoRESUMEN
Aerobic training led to enhancement of lipase activity in type IIA type muscles. Still more obvious changes were found in rats trained to aerobic swimming with maximal intensity. In latter activity, a rise of the fatty acid-binding protein (FABP) was revealed in types I and IIA skeletal muscles. These adaptive changes led to enhancement of lipid metabolism. It was also shown that the FABP content decreased after physical exercise more obviously in the trained animals due, probably, to their substance turnover enhancement.
Asunto(s)
Ácidos Grasos/metabolismo , Lipasa/metabolismo , Músculo Esquelético/metabolismo , Proteínas de Neoplasias , Proteínas del Tejido Nervioso , Condicionamiento Físico Animal , Resistencia Física , Adaptación Fisiológica , Animales , Transporte Biológico , Proteínas Portadoras/metabolismo , Proteína de Unión a los Ácidos Grasos 7 , Proteínas de Unión a Ácidos Grasos , Glucógeno/metabolismo , Hígado/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/enzimología , Músculo Esquelético/ultraestructura , RatasRESUMEN
High-carbohydrate nutrition was shown to increase the level of the blood serum glycated proteins in rats. The level reached its maximum in added aerobic physical exercises. However, there were no differences in insulin concentration, glycated hemoglobin level, (14-C)-thyroxine and (3-H)-glucose incorporation into the blood serum proteins in different groups of rats.