Changes in thyroxine monodeiodination in rat liver, kidney and placenta during pregnancy

1984 ◽  
Vol 107 (4) ◽  
pp. 495-499 ◽  
Author(s):  
Katsumi Yoshida ◽  
Michiko Suzuki ◽  
Toshiro Sakurada ◽  
Hirofumi Kitaoka ◽  
Nobuko Kaise ◽  
...  
Keyword(s):  
Rat Liver ◽  
Time Course ◽  
Outer Ring ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Sprague Dawley Rats ◽  
Tissue Homogenates ◽  
Liver And Kidney ◽  
Liver Homogenates

Abstract. Monodeiodination of thyrxoine (T4) was studied in the liver, kidney and placenta of pregnant rats. Age matched female non-pregnant and pregnant Sprague-Dawley rats on the 7th, 14th, 17th and 21st days of gestation were used. The 800 × g supernatants of tissue homogenates (protein 1 mg/tube) were incubated with 1 μg of stable T4 in the presence of 5 mm dithiothreitol (DTT) at 37°C for 60 min at pH 7.5. Net triiodothyronine (T3) generation from T4 in rat liver homogenates on the 7th day of gestation was significantly lower than that in the non-pregnant rat. Thereafter it increased, but values on the 14th, 17th and 21st days of gestation were not significantly different from those obtained in the non-pregnant rat. Net renal T3 generation from T4 on the 14th day was significantly lower than that in the non-pregnant rat. It was increased thereafter and the values at the 17th and 21st days of gestation were not significantly different from those in the non-pregnant rat. Net reverse T3 (rT3) generation from T4 in the placenta rose from the 14th to the 17th day and then dropped by the 21st day and the value at the 17th day was significantly higher than those at the 14th and 21st days of gestation. These results indcate that 1) both T4 outer-ring monodeiodination in the pregnant rat liver and kidney, and T4 inner-ring monodeiodination in the placenta show significant variation with the progress of gestation; 2) the time course of the T4 outer-ring monodeiodination in pregnant rat liver and kidney is completely different from T4 inner-ring monodeiodination in the placenta.

THE PRESENCE OF A MITOSIS INHIBITOR IN THE SERUM AND LIVER OF ADULT RATS

1958 ◽  
Vol 36 (8) ◽  
pp. 855-859 ◽  
Author(s):  
H. F. Stich ◽  
M. L. Florian
Keyword(s):  
Partial Hepatectomy ◽  
Specific Inhibitor ◽  
Mitotic Rate ◽  
Regenerating Liver ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Sprague Dawley Rats ◽  
Organ Specific ◽  
Tissue Homogenates ◽  
Liver Homogenates

The influence of serum and tissue homogenates on the mitotic rate of regenerating liver was tested. The following fractions were injected into Sprague–Dawley rats 24 hours after partial hepatectomy: (a) serum from normal 290–340 g. rats; (b) serum from rats 24 or 72 hours following partial hepatectomy; (c) liver homogenates from normal 290–340 g. rats; (d) regenerating liver homogenates (24 hours after partial hepatectomy); and, as controls, (e) brain homogenates representing non-mitotic tissues; (f) testes homogenates representing mitotically active tissues. Serum and liver from adult animals inhibit the onset of mitosis. Serum and regenerating liver from partially hepatectomized rats, as well as heterologous tissue, show no retarding effect.The results suggest the presence of an organ-specific inhibitor of mitosis in the serum and liver of adult animals.

Effect of bromocryptine on 20α-hydroxysteroiddehydrogenase regulation in the corpus luteum of the pregnant rat

1981 ◽  
Vol 98 (1) ◽  
pp. 133-136 ◽  
Author(s):  
K. Loewit ◽  
R. Kofler ◽  
M. Tabarelli ◽  
S. Schwarz
Keyword(s):  
Enzyme Activity ◽  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Placental Lactogen ◽  
Corpora Lutea ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Sprague Dawley Rats ◽  
Effective Doses

Abstract. Pregnant Sprague Dawley rats were passively immunized with antiserum to bovine luteinizing hormone (anti-LH) on day 10 of pregnancy, and treated with 1 mg/day or 1.5 mg/day of the prolactin (Prl) inhibitor bromocryptine (BEC) between days 10 to 12 or 9 to 12, respectively. On day 12 a laparotomy was performed to assess the state of pregnancy and to remove the ovaries for histochemical detection of 20α-hydroxysteroiddehydrogenase (20α-OHSD) in the corpora lutea of pregnancy. In a second experiment pregnant rats were treated with 1.5mg BEC/day from days 17 to 22, checked for foetal state and ovariectomized on day 22 before giving birth. Treatment with BEC in effective doses did not interfere with anti-LH-induced termination of pregnancy and consequent reappearance of 20α-OHSD activity on day 12, or with spontanenous recurrence of enzyme activity at the end of gestation. It is concluded that Prl has no direct and immediate role in 20α-OHSD regulation, at least on day 12, although substitution by endogenous rat placental lactogen at the end of pregnancy cannot be excluded.

THE PRESENCE OF A MITOSIS INHIBITOR IN THE SERUM AND LIVER OF ADULT RATS

1958 ◽  
Vol 36 (1) ◽  
pp. 855-859 ◽  
Author(s):  
H. F. Stich ◽  
M. L. Florian
Keyword(s):  
Partial Hepatectomy ◽  
Specific Inhibitor ◽  
Mitotic Rate ◽  
Regenerating Liver ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Sprague Dawley Rats ◽  
Organ Specific ◽  
Tissue Homogenates ◽  
Liver Homogenates

The influence of serum and tissue homogenates on the mitotic rate of regenerating liver was tested. The following fractions were injected into Sprague–Dawley rats 24 hours after partial hepatectomy: (a) serum from normal 290–340 g. rats; (b) serum from rats 24 or 72 hours following partial hepatectomy; (c) liver homogenates from normal 290–340 g. rats; (d) regenerating liver homogenates (24 hours after partial hepatectomy); and, as controls, (e) brain homogenates representing non-mitotic tissues; (f) testes homogenates representing mitotically active tissues. Serum and liver from adult animals inhibit the onset of mitosis. Serum and regenerating liver from partially hepatectomized rats, as well as heterologous tissue, show no retarding effect.The results suggest the presence of an organ-specific inhibitor of mitosis in the serum and liver of adult animals.

scholarly journals Isoelectric focusing of glutathione S-transferases from rat liver and kidney

1978 ◽  
Vol 175 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Barbara F. Hales ◽  
Valerie Jaeger ◽  
Allen H. Neims
Keyword(s):  
Substrate Specificity ◽  
Isoelectric Focusing ◽  
Transferase Activity ◽  
Sprague Dawley ◽  
Substrate Specificities ◽  
Liver Cytosol ◽  
Sprague Dawley Rats ◽  
Isoelectric Points ◽  
Liver And Kidney ◽  
Glutathione S Transferases

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.

Influence of Slice Thickness and Culture Conditions on the Metabolism of 7-Ethoxycoumarin in Precision-cut Rat Liver Slices

1998 ◽  
Vol 26 (4) ◽  
pp. 541-548
Author(s):  
Roger J. Price ◽  
Anthony B. Renwick ◽  
Paula T. Barton ◽  
J. Brian Houston ◽  
Brian G. Lake
Keyword(s):  
Gas Phase ◽  
Rat Liver ◽  
Xenobiotic Metabolism ◽  
Culture Conditions ◽  
Slice Thickness ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Liver Slices ◽  
Sprague Dawley Rats ◽  
Rat Livers

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.

Distribution and metabolism of corticotropin-releasing factor in the rat

1986 ◽  
Vol 64 (6) ◽  
pp. 683-688 ◽  
Author(s):  
Bernard Candas ◽  
Josée Lalonde ◽  
Maurice Normand
Keyword(s):  
Time Course ◽  
Corticotropin Releasing Factor ◽  
Metabolic Clearance ◽  
Sprague Dawley ◽  
Rapid Injection ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
The Mean ◽  
The Moment ◽  
The One

To develop a mathematical model of the distribution and metabolism of rat corticotropin-releasing factor (rCRF), the time course of 125I-labelled rCRF in plasma was measured in male Sprague–Dawley rats (i) following a rapid injection of 24 ng rCRF/100 g body weight (BW), or (ii) following a rapid injection of 424 ng rCRF/100 g BW, or (iii) during an infusion at a rate ranging from 0.28 to0.73 ng rCRF∙min−1∙100 g BW−1. The comparison of the one-, two-, and three-compartment models shows that the two-pool structure fits better to the dynamics of CRF in plasma as measured in each rat. Following a rapid injection the decay curve occurs in a biphasic manner; the early phase of disappearance is 25 times faster than the late one. There is no significant difference between the estimates of the metabolic clearance rate following both amplitudes of injection (0.40 ± 0.06 and 0.48 ± 0.05 mL∙min−1∙100 g BW−1). The volume of the first pool, 16.8 ± 1.1 mL/100 g BW, is four times larger than the plasma volume. It would thus appear that CRF is rapidly distributed from plasma into several tissues which are represented in the first pool of the model. The mean residence time of every CRF molecule in the second compartment, from the moment of secretion to its elimination, is from three to four times longer than in the first one. It stays, on average, between 140 min and 3 h in the system before an irreversible exit. At steady state, the disposal rate represents only 3% of the CRF mass of the first compartment every minute. These results could explain the prolonged effects of CRF on pituitary-adrenocortical secretion.

Effect of Gasohol on The Rat Liver

1997 ◽  
Vol 3 (S2) ◽  
pp. 49-50
Author(s):  
B.A. MacDuff ◽  
A. Singh ◽  
I. Chu
Keyword(s):  
United States ◽  
Body Weight ◽  
Adverse Effects ◽  
Rat Liver ◽  
Corn Oil ◽  
The United States ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

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.

Time course of peripheral heterothermy in a homeotherm

1980 ◽  
Vol 239 (1) ◽  
pp. R126-R129 ◽  
Author(s):  
R. T. Brown ◽  
J. G. Baust
Keyword(s):  
Room Temperature ◽  
Time Course ◽  
Temperature Fluctuations ◽  
Temperature Gradients ◽  
Tissue Temperature ◽  
Central Component ◽  
Sprague Dawley ◽  
Contralateral Limb ◽  
Sprague Dawley Rats ◽  
Peripheral Temperature

The integrity of the peripheral heterothermic response was monitored in adult Sprague-Dawley rats during cold acclimation. Subcutaneous peripheral temperature gradients were simultaneously recorded in the hindlimbs. One limb was exposed to room temperature (22 +/- 2 degrees C) while the contralateral limb was gradually cooled to 0 +/- 1 degrees C. Noncontrols were acclimated at 5 +/- 1 degrees C for periods up to 35 days. Controls responded to the cooling regimen (25 to 0 degrees C at 0.5 degrees C . min-1) in a "poikilothermic" manner indicating local cold-induced vasoconstriction (CIVC). CIVC was not released until tissue temperatures reached 22,3 +/- 2.5 degrees C whereupon nonpatterned limb temperature fluctuations, Lewis' hunting response, were often initiated. The hunting response occurred synchronously in the contralateral warmed limb despite its elevated temperature. The experiments revealed a progressive decrease in the intensity of heterothermy indicative of an earlier onset of cold-induced vasodilation as well as increased resistance to tissue cooling with increasing acclimation time. Following 21 days at 5 degrees C, limb exposure to 0 degrees C resulted in a 2-4 degrees C drop in tissue temperature. The time course of the diminution in peripheral heterothermy is discussed. In addition, evidence supporting the hypothesis of a central component in the regulation of the hunting response is presented.

Hepatic Stellate Cells Play a Functional Role in Exacerbating Ischemia-Reperfusion Injury in Rat Liver

2019 ◽  
Vol 60 (1-2) ◽  
pp. 74-85 ◽  
Author(s):  
Tomokazu Takahashi ◽  
Masato Yoshioka ◽  
Hiroshi Uchinami ◽  
Yasuhiko Nakagawa ◽  
Naohiko Otsuka ◽  
...  
Keyword(s):  
Rat Liver ◽  
Hepatic Stellate Cells ◽  
Functional Role ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Stellate Cells ◽  
Treated Group ◽  
Sprague Dawley ◽  
Perfusion Rate ◽  
Sprague Dawley Rats

Purpose: The involvement of hepatic stellate cells (HSCs) with ischemia-reperfusion (I/R) injury in rat liver was examined using gliotoxin, which is known to induce HSC apoptosis. Methods: Male Sprague-Dawley rats were used. HSC was represented by a glial fibrillary acidic protein (GFAP)-positive cell. Liver ischemia was produced by cross-clamping the hepatoduodenal ligament. The degree of I/R injury was evaluated by a release of aminotransferases. Sinusoidal diameter and sinusoidal perfusion rates were examined using intravital fluorescence microscopy. Results: Gliotoxin significantly decreased the number of GFAP-positive cells 48 h after dosing (2.50 ± 0.19% [mean ± SD] in the nontreated group vs. 1.91 ± 0.46% in the gliotoxin-treated group). Liver damage was significantly suppressed by the pretreatment with gliotoxin. Sinusoidal diameters in zone 3 were wider in the gliotoxin group (10.25 ± 0.35 µm) than in the nontreated group (8.21 ± 0.50 µm). The sinusoidal perfusion rate was maintained as well in the gliotoxin group as in normal livers, even after I/R. Conclusions: Pretreatment with gliotoxin significantly reduced the number of HSCs in the liver and further suppressed liver injury following I/R. It is strongly suggested that HSCs play a functional role in exacerbating the degree of I/R injury of the liver.

Cinnamomum cassia ameliorates Ni-NPs-induced liver and kidney damage in male Sprague Dawley rats

2020 ◽  
Vol 39 (11) ◽  
pp. 1565-1581
Author(s):  
S Iqbal ◽  
F Jabeen ◽  
C Peng ◽  
MU Ijaz ◽  
AS Chaudhry
Keyword(s):  
Dependent Manner ◽  
Sprague Dawley ◽  
Cinnamomum Cassia ◽  
Preliminary Information ◽  
Sprague Dawley Rats ◽  
Liver And Kidney ◽  
Altered Blood ◽  
Biochemical Analyses ◽  
Dose Dependent ◽  
Different Doses

Nickel nanoparticles (Ni-NPs) have been widely used in various industries related to electronics, ceramics, textiles, and nanomedicine. Ambient and occupational exposure to Ni-NPs may bring about potential detrimental effects on animals and humans. Thus, there is a growing effort to identify compounds that can ameliorate NPs-associated pathophysiologies. The present study examined Cinnamomum cassia ( C. cassia) bark extracts (CMBE) for its ameliorative activity against Ni-NPs-induced pathophysiological and histopathological alterations in male Sprague Dawley rats. The biochemical analyses revealed that dosing rats with Ni-NPs at 10 mg/kg/body weight (b.w.) significantly altered the normal structural and biochemical adaptations in the liver and kidney. Conversely, supplementations with CMBE at different doses (225, 200, and 175 mg/kg/b.w. of rat) ameliorated the altered blood biochemistry and reduced the biomarkers of liver and kidney function considerably ( p < 0.05) in a dose-dependent manner. However, the best results were at 225 mg/kg/b.w. of rat. The study provided preliminary information about the protective effect of C. cassia against Ni-NPs indicated liver and kidney damages. Future investigations are needed to explore C. cassia mechanism of action and isolation of single constituents of C. cassia to assess their pharmaceutical importance accordingly.

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