DISTRIBUTION OF RADIOACTIVITY IN THE DIFFERENT LOBES OF THE RAT PROSTATE FOLLOWING ADMINISTRATION OF TESTOSTERONE-1,2-3H

1969 ◽  
Vol 60 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Kjell J. Tveter

ABSTRACT Testosterone-1,2-3H with a specific activity of 46.5 c/mm was given intramuscularly to 3–4 months old, randomly selected rats, castrated 3 days before the injection. Radioactivity was measured in specimens from the ventral, dorsal and lateral prostatic lobes, and from the coagulating gland. A selective uptake of radioactivity relative to muscle tissue, was found in all parts of the prostate, with the same general pattern of incorporation. When correlated to wet weight, the maximum radioactivity was found in the lateral lobe. Eight hours after the injection the radioactivity in the lateral prostate was about 24 times higher than in muscle. The corresponding ratios for the ventral and dorsal lobes were 20:1 and 11:1, respectively. It is suggested that most of the radioactivity is localized within the cells, with minimal amounts of radioactivity in the secretory fluid.

1980 ◽  
Vol 239 (1) ◽  
pp. C18-C22 ◽  
Author(s):  
J. Himms-Hagen ◽  
C. Gwilliam

The size (wet weight, total protein, total cytochrome oxidase) of interscapular brown adipose tissue is reduced to about one-half of normal in the cardiomyopathic hamster (BIO 14.6). The mitochondria are normal in binding of purine nucleotides [guanosine 5'-diphosphate (GDP)] and in proportion of polypeptides in the region of 32,000, both indices of the thermogenic proton conductance pathway, and in specific activity of cytochrome oxidase. Brown adipose tissue of the cardiomyopathic hamster can grow during acclimation to 4 degrees C, but its size remains smaller than in cold-acclimated normal hamsters. Mitochondrial polypeptide composition is not altered by acclimation to cold, but a large increase in mitochondrial GDP binding occurs in both normal and cardiomyopathic hamsters. The reduced calorigenic response of cardiomyopathic hamsters to catecholamines (Horwitz, B.A., and G.E. Hanes, Proc. Soc. Exp. Biol. Med. 147: 393-395, 1974) may, at least in part, be explained by a reduction in the amount of brown adipose tissue, the major site of this response. A defect in control of growth of this tissue in the cardiomyopathic hamster is suggested.


1966 ◽  
Vol 53 (4) ◽  
pp. 655-662 ◽  
Author(s):  
István Kriskó ◽  
James B. Walker

ABSTRACT Arginine: glycine amidinotransferase is the first of two enzymes involved in creatine biosynthesis. The amidinotransferase specific activity (micromoles of hydroxyguanidine formed per hour per g wet weight of tissue) of kidney homogenates of mature male rats was about twice that of females of the same age, whereas activities were equal before puberty. Castration decreased the activity of males and increased that of females. The administration of testosterone propionate to young adult female rats resulted in a significant increase in enzyme activity. The same enzyme had previously been shown to be repressible by its end-product, creatine. Although there are numerous enzymes whose synthesis is known to be under hormonal control, amidinotransferase is the only mammalian enzyme described up to now on which there appears to operate both an end-product repression mechanism and a hormonal control on the de novo synthesis of the enzyme protein.


1986 ◽  
Vol 37 (3) ◽  
pp. 309 ◽  
Author(s):  
JM Lyle

Total mercury, alkyl mercury and selenium concentrations in the muscle tissue of 15 carcharhinid (Carcharhinus sp., C. limbatus, C. sorrah, C. fitzroyensis, C. amblyrhynchoides, C. melanopterus, C. cautus, C. amboinensis, C. macloti, C. dussumieri, C. brevipinna, Rhizoprionodon acutus, R. taylori, Galeocerdo cuvieri, Negaprion acutidens) and three hammerhead (Sphyrna lewini, S. mokarran and S. blochii) sharks from northern Australian waters are reported. Total mercury concentrations ranged widely with maximum individual concentrations exceeding 1.5 mg kg-1 wet weight in 11 species and values of over 3.0 mg kg-1 in Carcharhinus sp., C. amblyrhynchoides, C. melanopterus, C. amboinensis and S. mokarran. Much of the variability in total mercury concentration was attributable to differences in length. Total mercury was adequately correlated with fork length by the power function relationship. There were signficiant differences in these relationships for males and females of six species: males had higher concentrations of mercury than females of the same size. Weighted mean mercury concentrations were calculated using species and size composition data from commercial feasibility fishing trials. Weighted means for species other than C. sorrah, C. macloti, C. brevipinna and C. dussumieri were greater than 0.5 mg kg-1 and the value for the combined catch of all species was 1.22 mg kg-1. Alkyl mercury comprised over 80% of the total mercury content in the muscle tissue. Maximum individual selenium concentrations were greater than 1.0 mg kg-1 in nine species and the maximum concentration recorded was 3.4 mg kg-1 for C. dussumieri. There were no obvious or consistent relationships between selenium concentration and fork length or between selenium and mercury concentrations.


1996 ◽  
Vol 76 (4) ◽  
pp. 627-637 ◽  
Author(s):  
Patricia Deloyer ◽  
Guy Dandrifosse ◽  
Catherine Bartholomeus ◽  
Nadine Romain ◽  
Monique Klimek ◽  
...  

We questioned whether polyamines coming from the diet or produced by intestinal microflora or by intracellular metabolism influence intestinal functions. Therefore, we compared pathogen-free rats and germ-free rats receiving a diet with low polyamine content and either treated or not treated with difluoromethylornithine (DFMO) and/or methylglyoxal bis (guanylhydrazone) (MGBG). Wet weight, protein content, DNA content, sucrase (EC3.2.1.48), maltase (EC 3.2.1.20) and lactase (EC 3.2.1.23) specific activities, amounts of putrescine, spennidine and spemine were measured in the mucosa of the proximal and distal intestine. Body weight was also determined. Rats without microflora had a higher specific activity of maltase and higher amounts of spermidine and spermine but lower lactase specific activity than pathogen-free animals; the low-polyamine diet given to gem-free rats had little effect on the functional variables measured (decrease of maltase and lactase specific activities) and did not modify the amounts of polyamines. DFMO and/or MGBG administered to germ-free rats receiving a low-polyamine diet induced modifications of most of the variables studied. Body weight and wet weight of proximal and distal intestine decreased, disaccharidase specific activities decreased, and amounts of polyamines changed according to the inhibitor used. Thus, our results showed that the deprivation of polyamine supply from microflora or from the diet failed, under our experimental conditions, to affect the intestinal properties analysed but exogenous and endogenous polyamine restriction altered general properties of the organism as well as intestinal functions.


2008 ◽  
Vol 52 (No. 4) ◽  
pp. 175-177 ◽  
Author(s):  
E. Srebocan ◽  
J. Pompe-Gotal ◽  
A. Prevendar-Crnic ◽  
E. Ofner

Levels of total mercury in the muscle (29 samples) and liver tissue (15 samples) of bluefin tuna (<i>Thunnus thynnus</i>) weighing 100&minus;300 kg were determined by cold vapour atomic absorption (AA) spectroscopy. Tunas were previously captured in the waters of Malta, towed to the farm in the Adriatic Sea and fattened with defrosted herring and sardine for the period of 6 to 7 months. The purpose of the investigation was to determine the magnitude of mercury contamination and to ascertain whether the concentrations in muscle tissue exceeded the maximum level defined by the European Commission Decision (1 &mu;g/g wet weight). Total mercury concentrations in the muscle tissue of tunas ranged from 0.49 to 1.809 (median 0.899 &mu;g/g wet weight) while in the liver tissue it was from 0.324 to 3.248 (median 1.165 &mu;g/g wet weight). Total mercury concentrations in six samples of sardine ranged from 0.050 to 0.072 &mu;g/g wet weight while two samples of herring contained 0.020 and 0.053 &mu;g/g wet weight. Twelve out of 29 (41%) muscle samples of tuna contained mercury above the maximum level defined by the European Commission Decision. It is generally believed that mercury levels in Mediterranean fish are higher than those of the other seas or oceans due to numerous deposits of mercury ores and metallic mercury in surrounding countries.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Filipe F Conti ◽  
Andrea Linares ◽  
Leena E Couling ◽  
Mariana Morris ◽  
Katia De Angelis ◽  
...  

Despite the plethora of data indicating beneficial effects of angiotensin (1-7) (Ang 1-7) on the cardiovascular system, its putative receptor, Mas, has not been characterized in tissue membrane preparations other than single concentration demonstrations of the localization of 125 I-Ang 1-7 binding sites in rat kidney. This does not indicate the specificity of 125 I-Ang 1-7 binding nor does it indicate the actual densities of the binding sites, i.e., B max (fmoles/mg tissue), or dissociation constant (K D ) to indicate binding affinity of 125 I-Ang 1-7 for its putative receptor. To characterize 125 I-Ang 1-7 binding in the kidney we prepared a low specific activity, monoradioiodinated Ang 1-7 using a 1:19 mix of 125 iodine : 127 iodine which allows for assessment of the B max and K D with concentrations of radioligand up to 100 nM. Frozen kidneys from adult male albino rats were dissected and homogenized in water and the membranes were precipitated by centrifugation at 48 kxG. Membranes were resuspended in Tris:MgCl 2 (50:1) pH 7.2 and incubated with 12 concentrations of 125/127 I-Ang 1-7 ranging from ~3-100 nM for 30 min at 22 C, after which bound 125/127 I-Ang 1-7 was resolved from unbound 125/127 I-Ang 1-7 by filtration and measured with a gamma counter. Specific binding (defined as 100 μM Ang 1-7 displaceable binding) of 125/127 I-Ang 1-7 showed a moderate binding affinity (K D = 14.7 ± 1.8 nM) and binding site density (B max = 24.5 ± 9.9 fmoles/mg initial wet weight). The B max value tended to be lower than that in the liver (B max = 62.3 ± 20.1 fmoles/mg initial wet weight) and the K D value was significantly greater (lower affinity) than that in the liver ( K D = 5.7 ± 0.6 nM, p = 0.0085). Of note, competition for 125/127 I-Ang 1-7 binding Ang 1-7 indicated that the IC 50 for Ang 1-7 competition for 125/127 I-Ang 1-7 binding was 42.5 μM. Moreover, the ability of a variety of angiotensin peptides to inhibit 125/127 I-Ang 1-7 binding at 100 μM, Ang 1-7 was less potent that the other angiotensin peptides: Ang III > Ang II > Ang I ~ Ang IV > Ang 2-7 > Ang 1-7 ~ Ang 3-7. These studies suggest that the binding site for 125/127 I-Ang 1-7 is not specific for the putative Ang 1-7 receptor mas, and may represent a low affinity binding to the AT 1 or AT 2 receptor


1968 ◽  
Vol 46 (5) ◽  
pp. 549-555 ◽  
Author(s):  
Jennifer M. Walker ◽  
E. R. Waygood

Photosynthesis of a single shoot of Phragmites communis Trin. var. berlandieri (Fourn.) Fern., growing isolated from a stand, was measured in situ by enclosing it in a plastic bag of volume 107 liters and administering 1 mcurie of 14CO2 (specific activity, 5 mcurie per mmole) for 1 hour under a cloudless sky (light intensity > 100 000 lux; photoperiod, 16.5 h). The plant was 164 cm in height with 15 internodes, 11 expanded leaves, and a terminal unrolled leaf. The leaves, leaf sheaths, and internodes were removed, frozen between blocks of solid CO2, and subsequently extracted by the method of Bieleski and Turner (Anal. Biochem. 17, 278–293 (1966)). 14CO2 incorporation was determined in extracts of the plant parts by a scintillation analyzer.Photosynthetic rates were calculated per leaf, per square decimeter of leaf, per gram wet weight, and per μmole of leaf chlorophyll. Greatest incorporation of 14CO2 was found in the centrally inserted leaves. Leaf sheaths and internodes fixed only 8% of the total. Leaf area was the only useful index of photosynthesis averaging 6.1 (S.D. ± 0.62) mg CO2/dm2 per hour. On a gram wet weight basis the rate of photosynthesis increased in a hyperbolic relationship from the lowest to the uppermost leaves. Chlorophyll was determined on leaves from an adjacent plant of similar size and structure. On this basis the centrally inserted leaves were the least and the upper leaves were the most efficient, the uppermost expanded leaf having a rate of 163 µmoles CO2 per µmole chlorophyll per hour (assimilation time = 22 seconds). Productivity, in terms of carbon fixed, was 3.5 g/m2 per day based on a mean density of 12.75 plants per 0.25 m2 and a 10-hour day.


Neurosurgery ◽  
1990 ◽  
Vol 26 (2) ◽  
pp. 248-254 ◽  
Author(s):  
John S. Hill ◽  
Andrew H. Kaye ◽  
William H. Sawyer ◽  
George Morstyn ◽  
Phillip D. Megison ◽  
...  

Abstract The uptake of hematoporphyrin derivative (HpD) into human cerebral glioma was measured using a porphyrin extraction technique. Patients with cerebral glioma were injected with HpD at a dose of 5 mg/kg body weight 24 hours before surgery and photoradiation therapy (PRT). Biopsies of tumor, and where possible, adjacent brain and normal brain were taken for analysis of HpD uptake. HpD was selectively localized into all grades of glioma, and there was a direct correlation between the grade of glioma and HpD level in the tumor. The levels were highest in glioblastoma multiforme (mean uptake of 5.9 mg of HpD/g of tumor wet weight) and lower in the intermediate-grade anaplastic astrocytoma (mean uptake of 2.4 mg/g of tumor) and the low-grade astrocytoma (1.6 mg/g of tumor), Uptake into normal brain tissue taken from HpD-sensitized patients was 0.2 mg/g. HpD was also localized into the “brain adjacent to tumor” region. The selective uptake into the low-grade glioma suggests that PRT may be of use as an adjuvant therapy in these tumors and the detection of HpD in this region indicates that PRT may control the spread of tumor infiltrating into the adjacent normal brain.


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