scholarly journals Strain differences in rat liver (UDP-glucuronyltransferase activity towards androsterone

1979 ◽  
Vol 179 (3) ◽  
pp. 483-487 ◽  
Author(s):  
M Matsui ◽  
F Nagai ◽  
S Aoyagi

Male Donryu, Wistar King rats showed discontinuous variations in hepatic microsomal UDP-glucuronyltransferase activities towards androsterone, but not towards testosterone, bilirubin, phenolphthalein and 4-nitrophenol. Fresh microsomal fraction with a low transferase activity towards androsterone formed 0.049–0.080 nmole of glucuronide/min per mg of protein, whereas fresh microsomal fraction with a high transferase activity towards androsterone formed 0.335–0.557 nmol of glucuronide/min per mg of protein. The microsomal fraction with low enzyme activity towards androsterone was not stimulated by treatment with Triton X-100 or freezing and thawing. In contrast, male Long Evans and Sprague-Dawley rats did not exhibit such diversity.

1970 ◽  
Vol 117 (2) ◽  
pp. 319-324 ◽  
Author(s):  
G. J. Mulder

1. The detergent Triton X-100 activates UDP glucuronyltransferase from rat liver in vitro six- to seven-fold with p-nitrophenol as substrate. The enzyme activity when measured in the presence of Triton X-100 is increased significantly by pretreatment of male rats with phenobarbital for 4 days (90mg/kg each day intraperitoneally). If no Triton X-100 is applied in vitro such an increase could not be shown. In all further experiments the enzyme activity was measured after activation by Triton X-100. 2. The Km of the enzyme for the substrate p-nitrophenol does not change on phenobarbital pretreatment. 3. When the microsomal fraction from the liver of untreated rats is subfractionated on a sucrose density gradient, 47% of the enzyme activity is recovered in the rough-surfaced microsomal fraction, which also has a higher specific activity than the smooth-surfaced fraction. 4. Of the increase in activity after the phenobarbital pretreatment 50% occurs in the smooth-surfaced fraction, 19% in the rough-surfaced fraction and 31% in the fraction located between the smooth- and rough-surfaced microsomal fractions on the sucrose density gradient. 5. The latency of the enzyme in vitro, as shown by the effect of the detergent Triton X-100, is discussed in relation to the proposed heterogeneity of UDP glucuronyltransferase.


2006 ◽  
Vol 27 (3) ◽  
pp. 136-146 ◽  
Author(s):  
Rachel M. Ceballos ◽  
Martha M. Faraday ◽  
Laura Cousino Klein

The effects of immobilization (IM) stress on plasma leptin levels and bodyweight in adult Sprague-Dawley (19 males, 20 females) and Long-Evans (20 males, 20 females) rats were investigated. Following a 10-day baseline period, half the animals from each experimental group were exposed to immobilization stress or no-stress 20 min/day for 21 days. Plasma leptin and corticosterone levels were measured following stress or no-stress exposure on the last day of the experiment. Corticosterone levels confirmed stress exposure. Important interactive effects of stress, strain, and sex on leptin and corticosterone levels were also observed. Specifically, females displayed higher leptin levels than did males, regardless of stress exposure. Strain interacted with stress such that stressed Long-Evans rats displayed higher leptin levels than did stressed Sprague-Dawley rats; there were no strain differences in leptin levels among nonstressed rats. Also, correlations between leptin and corticosterone were strain-specific. Results are discussed with respect to previously unreported strain differences in the effects of immobilization stress on circulating plasma leptin and the relevance to inconsistent findings in the human literature.


2009 ◽  
Vol 26 (4) ◽  
pp. 539-548 ◽  
Author(s):  
Arlene A. Tan ◽  
Andrea Quigley ◽  
Douglas C. Smith ◽  
Michael R. Hoane

1964 ◽  
Vol 14 (3) ◽  
pp. 775-779 ◽  
Author(s):  
Eugene F. Gauron

Infant rats of two strains were exposed to two types of shock traumatization in infancy: escapable and inescapable. The strains included Sprague-Dawley rats and Long-Evans hooded rats. Animals were tested in adulthood on open-field test, avoidance conditioning, and water escape maze. Statistical analysis yielded several significant Strain × Treatment interactions which suggest that strain of the animal and type of traumatization are potential influencing variables in the nature and direction of the effect produced by early traumatization. Such genetic and ontogenetic interaction complicates the issue of the nature of the effect produced by early experience.


Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.


1978 ◽  
Vol 175 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Barbara F. Hales ◽  
Valerie Jaeger ◽  
Allen H. Neims

The glutathione S-transferases that were purified to homogeneity from liver cytosol have overlapping but distinct substrate specificities and different isoelectric points. This report explores the possibility of using preparative electrofocusing to compare the composition of the transferases in liver and kidney cytosol. Hepatic cytosol from adult male Sprague–Dawley rats was resolved by isoelectric focusing on Sephadex columns into five peaks of transferase activity, each with characteristic substrate specificity. The first four peaks of transferase activity (in order of decreasing basicity) are identified as transferases AA, B, A and C respectively, on the basis of substrate specificity, but the fifth peak (pI6.6) does not correspond to a previously described transferase. Isoelectric focusing of renal cytosol resolves only three major peaks of transferase activity, each with narrow substrate specificity. In the kidney, peak 1 (pI9.0) has most of the activity toward 1-chloro-2,4-dinitrobenzene, peak 2 (pI8.5) toward p-nitrobenzyl chloride, and peak 3 (pI7.0) toward trans-4-phenylbut-3-en-2-one. Renal transferase peak 1 (pI9.0) appears to correspond to transferase B on the basis of pI, substrate specificity and antigenicity. Kidney transferase peaks 2 (pI8.5) and 3 (pI7.0) do not correspond to previously described glutathione S-transferases, although kidney transferase peak 3 is similar to the transferase peak 5 from focused hepatic cytosol. Transferases A and C were not found in kidney cytosol, and transferase AA was detected in only one out of six replicates. Thus it is important to recognize the contribution of individual transferases to total transferase activity in that each transferase may be regulated independently.


1998 ◽  
Vol 26 (4) ◽  
pp. 541-548
Author(s):  
Roger J. Price ◽  
Anthony B. Renwick ◽  
Paula T. Barton ◽  
J. Brian Houston ◽  
Brian G. Lake

This study investigated the effects of some experimental variables on the rate of xenobiotic metabolism in precision-cut rat liver slices. Liver slices of 123 ± 8μm (mean ± SEM of six slices), 165 ± 3μm, 238 ± 6μm and 515 ± 14μm thickness were prepared from male Sprague-Dawley rats, and incubated in RPMI 1640 medium in an atmosphere of 95% O2/5% CO2 by using a dynamic organ culture system. Liver slices of all thicknesses metabolised 10μM 7-ethoxycoumarin to total (free and conjugated) 7-hydroxycoumarin in a time-dependent manner. The rate of 7-ethoxycoumarin metabolism was greatest in 165μm thick slices and slowest in 515μm thick slices, being 2.74 ± 0.19pmol/minute/mg slice protein and 0.69 ± 0.07pmol/minute/mg slice protein, respectively. No marked effects on the rate of 7-ethoxycoumarin metabolism in liver slices were observed either by changing the medium to Earle's balanced salt solution (EBSS) or by changing the gas phase to 95% air/5% CO2. Moreover, the perfusion of rat livers with EBSS at 2–4°C, prior to preparation of tissue cores, did not enhance 7-ethoxycoumarin metabolism in rat liver slices. In this study, the optimal slice thickness was 175μm, with higher rates of 7-ethoxycoumarin metabolism being observed than with 250μm thick slices, which are often used for studies of xenobiotic metabolism. Variable results were obtained with slices of around 100–120μm thickness, which may be attributable to the ratio between intact hepatocytes and cells damaged by the slicing procedure in these very thin slices.


Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Xuechai Chen ◽  
Abida Arshad ◽  
Hong Qing ◽  
Rui Wang ◽  
Jianqing Lu ◽  
...  

AbstractSalsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline; Sal) is structurally similar to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which is supposed to have a role in the development of Parkinson-like syndrome in both human and non-human subjects. In the human brain, the amount of (R)-enantiomer of Sal is much higher than (S)-enantiomer, suggesting that a putative enzyme may participate in the synthesis of (R)-salsolinol, called (R)-salsolinol synthase. In this study, the (R)-salsolinol synthase activity in the condensation of dopamine and acetaldehyde was investigated in the crude extracts from the brains of Sprague Dawley rats. Identification of the enzymatic reaction products and enzyme activity detection were achieved by HPLC-electrochemical detection. The discovery of this enzyme activity in rat’s brain indicates the natural existence of (R)-salsolinol synthase in the brains of humans and rats, and it is distributed in most brain regions of rat with higher activity in soluble proteins extracted from striatum and substantia nigra.


1997 ◽  
Vol 3 (S2) ◽  
pp. 49-50
Author(s):  
B.A. MacDuff ◽  
A. Singh ◽  
I. Chu

Although there are a variety of gasoline ethanol mixtures proposed as neat fuels (ethanol 85% + gasoline 15% = E85; E95) for automobiles, gasohol (gasoline 90% + ethanol 10%) is presently used as a fuel in the United States. The adverse effects, if any, of gasohol ingestion are unknown; effects on the liver of rats administered gasohol are examined in this study.Twenty-four female Sprague-Dawley rats received daily, via gavage, one of the three concentrations of gasohol for 28 days; LD50/20, LD50/100 and LD50/1000, where LD50 = 1.5g ethanol / kg body weight (bw) and 14g gasoline / kg bw. The LD50 was based on that of gasoline, which was obtained from literature value.1 The amount of ethanol added to stock gasohol was only 1/10 its LD50, required to maintain the gasoline ethanol proportion of 9:1. Gasohol was administered in corn oil with total volume 10 ml. Animals that received only corn oil served as controls.


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