UPTAKE AND BINDING IN VIVO OF 3H LABELLED ANDROGEN IN THE RAT EPIDIDYMIS AND DUCTUS DEFERENS

1971 ◽  
Vol 66 (4) ◽  
pp. 745-755 ◽  
Author(s):  
Vidar Hansson ◽  
Kjell J. Tveter
Keyword(s):  
Skeletal Muscle ◽  
Male Rats ◽  
Supernatant Fraction ◽  
Nuclear Fraction ◽  
Simultaneous Administration ◽  
Ductus Deferens ◽  
Selective Uptake ◽  
Rat Epididymis ◽  
Androgen Binding

ABSTRACT Following the administration of [3H] testosterone and [3H]5α-dihydrotestosterone to adult castrated male rats, a selective uptake of androgen was found in the epididymis and ductus deferens,in contrast to the much lower uptake by skeletal muscle. Simultaneous administration of non-labelled androgen reduced the uptake in the epididymis and ductus deferens by about 60–70 per cent. One day after castration, the uptake in the epididymis was about 54 per cent higher than in the intact animals. The 105 000 × g supernatant fraction of homogenates obtained from both the ductus deferens and the epididymis, contained androphilic macromolecules excluded from Sephadex G-100 gel. The 600 × g crude nuclear fraction of homogenized epididymal tissue contained salt extractable androgen binding macromolecules.

scholarly journals Effects of Prolonged Dietary Curcumin Exposure on Skeletal Muscle Biochemical and Functional Responses of Aged Male Rats

2019 ◽  
Vol 20 (5) ◽  
pp. 1178 ◽  
Author(s):  
Candace Receno ◽  
Chen Liang ◽  
Donna Korol ◽  
Mustafa Atalay ◽  
Kevin Heffernan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Food Intake ◽  
Muscle Mass ◽  
Male Rats ◽  
Antioxidant Defenses ◽  
Related Factor ◽  
Nuclear Fraction ◽  
Functional Responses ◽  
The Impact

Oxidative stress resulting from decreased antioxidant protection and increased reactive oxygen and nitrogen species (RONS) production may contribute to muscle mass loss and dysfunction during aging. Curcumin is a phenolic compound shown to upregulate antioxidant defenses and directly quench RONS in vivo. This study determined the impact of prolonged dietary curcumin exposure on muscle mass and function of aged rats. Thirty-two-month-old male F344xBN rats were provided a diet with or without 0.2% curcumin for 4 months. The groups included: ad libitum control (CON; n = 18); 0.2% curcumin (CUR; n = 18); and pair-fed (PAIR; n = 18) rats. CUR rats showed lower food intake compared to CON, making PAIR a suitable comparison group. CUR rats displayed larger plantaris mass and force production (vs. PAIR). Nuclear fraction levels of nuclear factor erythroid-2 related-factor-2 were greater, and oxidative macromolecule damage was lower in CUR (vs. PAIR). There were no significant differences in measures of antioxidant status between any of the groups. No difference in any measure was observed between CUR and CON rats. Thus, consumption of curcumin coupled with reduced food intake imparted beneficial effects on aged skeletal muscle. The benefit of curcumin on aging skeletal muscle should be explored further.

Regulation of glucose transporter GLUT-4 and hexokinase II gene transcription by insulin and epinephrine

1997 ◽  
Vol 273 (4) ◽  
pp. E682-E687 ◽  
Author(s):  
Jared P. Jones ◽  
G. Lynis Dohm
Keyword(s):  
Skeletal Muscle ◽  
Gene Transcription ◽  
Glucose Transporter ◽  
Male Rats ◽  
Rat Skeletal Muscle ◽  
Hexokinase Ii ◽  
Epinephrine Infusion ◽  
Glut 4 ◽  
Gastrocnemius Muscles

Transport of glucose across the plasma membrane by GLUT-4 and subsequent phosphorylation of glucose by hexokinase II (HKII) constitute the first two steps of glucose utilization in skeletal muscle. This study was undertaken to determine whether epinephrine and/or insulin regulates in vivo GLUT-4 and HKII gene transcription in rat skeletal muscle. In the first experiment, adrenodemedullated male rats were fasted 24 h and killed in the control condition or after being infused for 1.5 h with epinephrine (30 μg/ml at 1.68 ml/h). In the second experiment, male rats were fasted 24 h and killed after being infused for 2.5 h at 1.68 ml/h with saline or glucose (625 mg/ml) or insulin (39.9 μg/ml) plus glucose (625 mg/ml). Nuclei were isolated from pooled quadriceps, tibialis anterior, and gastrocnemius muscles. Transcriptional run-on analysis indicated that epinephrine infusion decreased GLUT-4 and increased HKII transcription compared with fasted controls. Both glucose and insulin plus glucose infusion induced increases in GLUT-4 and HKII transcription of twofold and three- to fourfold, respectively, compared with saline-infused rats. In conclusion, epinephrine and insulin may regulate GLUT-4 and HKII genes at the level of transcription in rat skeletal muscle.

scholarly journals In vivo uptake of [14C]leucine by skeletal muscle ribosomes after injury in rats fed two levels of protein

1969 ◽  
Vol 23 (2) ◽  
pp. 271-280 ◽  
Author(s):  
V. R. Young ◽  
P. C. Huang
Keyword(s):  
Skeletal Muscle ◽  
Specific Activity ◽  
Male Rats ◽  
Thigh Muscle ◽  
Left Femur ◽  
The Right ◽  
And Control ◽  
The Relationship ◽  
In Vivo Uptake

1. After 14 days on a diet containing 5 or 25% casein male rats received a fracture of the left femur. Four hours before they were killed the injured and control rats were injected with [1-14C]leucine; the incorporation of radioactivity into an isolated fraction of skeletal muscle ribosomes was studied 6, 12, 24, 48, 72, 96 and 228 h after injury.2. The incorporation of [14C]leucine into the ribosome fraction in right thigh muscles dropped to 40% of control values 72 h after fracture in well-nourished rats and after 96 h with diets containing 5 or 25%, casein.3. The specific activity of the trichloroacetic acid-soluble fraction of muscle from injured rats was equal to or higher than that of the controls during the first 72 h but lower at 96 h.4. These results suggest that a reduced incorporation of amino acids by ribosomes from the right thigh muscle occurred on day 3 after fracture in the group receiving 25% casein but not in the group receiving 5% casein.5. Muscle RNA and DNA concentrations were not affected by the injury.6. The relationship between these findings and the loss of muscle N after injury is discussed.

Rat skeletal muscle hexokinase II mRNA and activity are increased by a single bout of acute exercise

1994 ◽  
Vol 266 (2) ◽  
pp. E171-E178 ◽  
Author(s):  
R. M. O'Doherty ◽  
D. P. Bracy ◽  
H. Osawa ◽  
D. H. Wasserman ◽  
D. K. Granner
Keyword(s):  
Skeletal Muscle ◽  
Acute Exercise ◽  
Recovery Period ◽  
Exhaustive Exercise ◽  
Male Rats ◽  
Hexokinase Ii ◽  
Glut 4 ◽  
Heat Stable ◽  
Single Bout

This study addresses the potential role of skeletal muscle hexokinase (HK) II in the regulation of glucose uptake and metabolism in vivo. Male rats undertook a single bout of treadmill exercise and were then killed immediately or after a predetermined recovery period. Three muscles [soleus (Sol), gastrocnemius/plantaris (Gc), and white vastus] were excised, and HK II mRNA, GLUT-4 mRNA, total HK (HK I and HK II) and heat-stable HK (predominantly HK I) activities were assessed. Three hours after the cessation of a single bout of exhaustive exercise, HK II mRNA was significantly increased in all three muscles. Ninety or thirty minutes of exercise, with a 3-h recovery, increased Gc HK II mRNA to the same extent as exhaustive exercise, but 15 min of exercise had no effect. Gc HK II mRNA continued to increase up to 8 h after the cessation of 90 min of exercise but returned to basal by 24 h postexercise. In contrast to HK II mRNA, Gc GLUT-4 mRNA was unchanged at 0, 3, 8, and 24 h after the cessation of 90 min of exercise. Total HK activity was significantly increased in Sol and Gc, 8 and 24 h after the cessation of 90 min of exercise. Heat-stable HK activity was unchanged in all three muscles. The increase in total HK activity, inferred to be an increase of HK II, may be important in the persistence of the postexercise increase in insulin action.

Anaesthetic Agents and Their Effect on Tissue Protein Synthesis in the Rat

1989 ◽  
Vol 77 (6) ◽  
pp. 651-655 ◽  
Author(s):  
S. D. Heys ◽  
A. C. Norton ◽  
C. R. Dundas ◽  
O. Eremin ◽  
K. Ferguson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Young Male ◽  
Male Rats ◽  
Liver Protein ◽  
Arterial Blood Gas ◽  
Anaesthetic Agents ◽  
Arterial Blood ◽  
Tissue Protein Synthesis

1. Rates of protein synthesis were measured, in vivo, in lung, liver, heart and skeletal muscle of young male rats. Groups of rats were exposed for 1 h duration to one of the following anaesthetic regimens: 1.4% halothane, 2.2% halothane, 1.4% halothane in 66% nitrous oxide, intravenous pentobarbitone (20 mg/kg) and intravenous midazolam (18 mg/kg) combined with fentanyl (2 μg/kg). Fractional rates of protein synthesis were determined by injecting [3H]phenylalanine (150 μmol/100 g body weight) 2. Liver protein synthesis was depressed significantly by all regimens, except midazolam/fentanyl, by up to 37.7% of control values. Lung protein synthesis was significantly reduced by all the anaesthetic agents by up to 30% of control rates 3. The effects of the anaesthetic agents on skeletal muscle and heart were small and not statistically significant 4. There was no evidence of ventilatory depression as manifested by changes in arterial blood gas partial pressures of CO2 and O2, except in the group treated with 2.2% halothane.

Role of insulin during exercise-induced glycogenesis in muscle: effect on cyclic AMP.

1977 ◽  
Vol 233 (6) ◽  
pp. E509 ◽  
Author(s):  
J L Ivy
Keyword(s):  
Skeletal Muscle ◽  
Cyclic Amp ◽  
Glycogen Synthesis ◽  
Male Rats ◽  
Control Treatment ◽  
Glycogen Depletion ◽  
Camp Content ◽  
Glucose Administration ◽  
Exercise Induced

Skeletal muscle cyclic AMP (cAMP) content and glycogen synthesis were investigated in male rats subjected to exhaustive exercise, alloxan diabetes, and combinations of these conditions. After an exhaustive swim or control treatment of wading, randomly selected animals were administered 500 mg glucose via stomach tube. Two hours after glucose administration, gastrocnemius glycogen levels rose from 1.31 to 10.67 mg/g wet wt in fatigued nondiabetics (FND), producing a 94% supercompensation above control values. Glycogen of fatigued diabetics (FD) increased from 0.88 to 4.21 mg/g wet wt during the first 2 hr after glucose administration and did not reach control values for 24 h. In conjunction with these glycogen changes, cAMP increased from 1.23 to 2.59 and 1.47 to 2.81 pmol/mg wet wt for FND and FD, respectively (P less than 0.05). No difference in cAMP levels between diabetics and nondiabetics was found. These in vivo data suggest that insulin may not be essential for muscle glycogen synthesis, but that after glycogen depletion it plays a prominent role in supercompensation. Also, this hormone's mechanism of action in skeletal muscle does not appear to be mediated through alteration in the tissue cAMP concentration.

METABOLISM IN VIVO OF [3H] ANDROSTENEDIONE AND [3H] TESTOSTERONE BY ANDROGEN DEPENDENT TISSUES

1970 ◽  
Vol 65 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Kjell J. Tveter ◽  
Asbjörn Aakvaag
Keyword(s):  
Intramuscular Injection ◽  
Total Activity ◽  
Seminal Vesicles ◽  
Radioactive Material ◽  
Male Rats ◽  
Ventral Prostate ◽  
Supernatant Fraction ◽  
Rectus Abdominis Muscle ◽  
Main Metabolite

ABSTRACT The radioactive material present in the different prostatic lobes and the seminal vesicles was isolated and identified after intramuscular injection of [1,2-3H] testosterone to adult castrated male rats. 5α-Dihydrotestosterone was the main metabolite, representing 70, 72, 49, 56 and 70%, respectively, of the total activity in the ventral, dorsal and lateral prostate, the coagulating glands and the seminal vesicles one hour after the administration of hormone. The corresponding values for unchanged [3H] testosterone were 16, 6.4, 23, 6 and 15%, respectively. In rectus abdominis muscle less than 0.3% was 5α-dihydrotestosterone, while 37% represented unconverted [3H] testosterone. Of the activity in liver, [3H]-testosterone accounted for 0.2%, whereas less than 0.1% was 5α-dihydrotestosterone. One hour after administration of [1,2-3H] androst-4-ene-3,17-dione to adult castrated rats, the uptake of radioactivity in the ventral prostate was about 2.7 times higher than in skeletal muscle. In the ventral prostate, 32% of the total activity present at this time was represented by 5α-dihydrotestosterone, while 3.5% was unmetabolized [3H] androstenedione. The corresponding values for the seminal vesicles were 24 and 3.7%, respectively. In the 105 000 × g supernatant fraction of homogenized ventral prostate tissue, part of the radioactivity was associated with soluble macromolecules one hour after the administration of [3H]-androstenedione.

BINDING AND METABOLISM OF 5α-ANDROSTANE-3α,17β-DIOL AND OF 5α-ANDROSTANE-3β,17β-DIOL IN THE PROSTATE, SEMINAL VESICLES AND PLASMA OF MALE RATS: STUDIES IN VIVO AND IN VITRO

1975 ◽  
Vol 64 (3) ◽  
pp. 529-538 ◽  
Author(s):  
M. KRIEG ◽  
H.-J. HORST ◽  
M.-L. STERBA
Keyword(s):  
Skeletal Muscle ◽  
Specific Binding ◽  
Biological Effects ◽  
Sucrose Density Gradient ◽  
Total Radioactivity ◽  
Seminal Vesicles ◽  
Male Rats ◽  
Cytosol Fraction

SUMMARY Binding of 5α-androstane-3α,17β-diol (3α-diol) and 5α-androstane-3β,17β-diol (3β-diol) in vivo and in vitro to the 100000 g cytosol fraction of the rat prostate and seminal vesicles as well as to plasma was studied by agargel electrophoresis and sucrose density gradient ultracentrifugation and the results compared with the corresponding findings for 5α-dihydrotestosterone (5α-DHT). The metabolism of 3α-diol and 3β-diol was also investigated by thin-layer chromatography. The following results were obtained: (1) A specific binding of 3α-diol and 3β-diol by the cytosols could not be demonstrated in vitro, while 5α-DHT was specifically bound. (2) In plasma, 3α-diol was extensively bound, 3β-diol less extensively bound, while 5α-DHT remained unbound. (3) After intravenous injection of 3α-diol, specifically bound radioactivity, increasing within 30 min, was found in the prostate cytosol, while after 3β-diol injection no binding occurred. (4) Parallel to the increased binding, the total radioactivity in the prostate accumulated within 30 min after 3α-diol injection, the uptake being 5·3 times higher than in skeletal muscle. However after 3β-diol injection, total radioactivity decreased in the prostate within 30 min, the uptake being only 1·5 times higher than in skeletal muscle. (5) One minute after injection of 3α-diol, 53% of the extracted radioactivity in the prostate had been converted to 5α-DHT, this increased within 30 min to 81%. Thirty minutes after the injection of 3β-diol, about 32% of the extracted radioactivity in the prostate had been converted to 5α-DHT. (6) From the in-vivo and in-vitro experiments it was concluded that 3α-diol exerts its biological effects mainly by its conversion into 5α-DHT.

EFFECT OF CARBENOXOLONE ON THE CONCENTRATIONS OF ALDOSTERONE IN RAT PLASMA AND KIDNEY

1979 ◽  
Vol 81 (1) ◽  
pp. 143-151 ◽  
Author(s):  
M. J. HUMPHREY ◽  
W. E. LINDUP ◽  
J. CHAKRABORTY ◽  
D. V. PARKE
Keyword(s):  
Binding Sites ◽  
Rat Kidney ◽  
Rat Plasma ◽  
Supernatant Fraction ◽  
Nuclear Fraction ◽  
Toad Skin ◽  
Site Of Action ◽  
Specific Receptors

The renal subcellular distribution of various subcutaneous doses (10−10–10−8 mol) of [3H]aldosterone has been investigated in adrenalectomized rats pretreated with carbenoxolone. Carbenoxolone increased the concentration of plasma [3H]aldosterone, but the uptake of [3H]aldosterone into the kidney nuclear and cytosol fractions was decreased. Pretreatment of rats with carbenoxolone at low doses of aldosterone (0·4 × 10−10 and 1·5 × 10−10 mol) decreased both the amount of [3H]aldosterone bound to the 50% (NH4)2SO4 precipitate, and that present in the supernatant fraction, of a Tris–CaCl2 extract of the kidney nuclear fraction. Carbenoxolone also decreased the rate of biliary excretion of metabolites of aldosterone. When [3H]aldosterone and carbenoxolone were incubated with Tris–CaCl2 extracts of a kidney nuclear fraction in vitro, the carbenoxolone did not decrease the [3H]aldosterone bound to the 50% (NH4)2SO4 precipitate, although the [3H]aldosterone bound to the 50% (NH4)2SO4 supernatant was significantly decreased by carbenoxolone at concentrations known to occur in the kidney in vivo. These results indicate that displacement of aldosterone from binding sites, with a concomitant potential increase in the amount of hormone available to specific receptors may be part of the mechanism by which carbenoxolone potentiates aldosterone action in toad skin in vitro. However, in rat kidney, such a mechanism is unlikely to play a significant role in the manifestation by carbenoxolone of aldosterone-like effects. Data are presented to indicate that carbenoxolone may affect the normal distribution and metabolism of aldosterone, and it is possible that potentiation of aldosterone action may involve receptors in other tissues, such as the gastrointestinal tract which is the major site of action of carbenoxolone.

Effects of hypoxia on in vivo glycine-C14 incorporation into pancreatic cell proteins

1965 ◽  
Vol 208 (6) ◽  
pp. 1177-1182 ◽  
Author(s):  
M. Don Turner ◽  
Anne C. Turner
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Liquid Scintillation ◽  
Experimental Series ◽  
Male Rats ◽  
Supernatant Fraction ◽  
Zymogen Granule ◽  
Pancreatic Cell ◽  
Cell Fractions

The effects of graded hypoxia on glycine-C14 incorporation into subcellular components were measured in the intact mammal. Groups of three fasted male rats were injected intraperitoneally with 5 µc of glycine-2-C14 and sacrificed at 5 (or 10), 15, 20, 30, and 45 min by decapitation. In one experimental series the environmental pO2 was maintained at 35 mm Hg for 2 hr before injection and throughout the experiment. In three other experimental series, the pO2 in the sealed chamber was maintained at 58, 48, and 38 mm Hg for 45 min before injection and for the duration of the experiment. The whole pancreases were rapidly removed, cooled, homogenized, and pooled before separation of cell fractions by ultracentrifugation. The specific activities (counts/min per µg of amino acid or protein N) were obtained for plasma and supernatant fraction ("cell sap") amino acids and for the purified proteins of zymogen granule, mitochondrial, microsomal, and cell sap fractions from micro-Kjeldahl analyses and liquid-scintillation counting. No detectable changes were found in the turnover of plasma amino acids during graded hypoxia. Amino acid incorporation into the proteins of all cell fractions was depressed stepwise with increasing degrees of hypoxia.

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