scholarly journals Metabolism of C19-steroids by homogenates of normal rat and mouse adrenal tissue and of the Snell transplantable rat adrenocortical tumour 494

1972 ◽  
Vol 126 (1) ◽  
pp. 99-106 ◽  
Author(s):  
P. V. Maynard ◽  
E. H. D. Cameron
Keyword(s):  
Reductase Activity ◽  
Steroid Metabolism ◽  
Sprague Dawley ◽  
Adrenal Tissue ◽  
Normal Rat ◽  
Rats And Mice ◽  
Adrenocortical Tumour

C19-steroid metabolism in homogenates of adrenal tissue from rats and mice has been studied. Production of these compounds from [7α-3H]cholesterol by rat adrenal tissue appeared to follow a route independent of pregnenolone. The major products of [7α-3H]-dehydroepiandrosterone metabolism by rat adrenal tissue were 5α-reduced steroids, principally androsterone, epiandrosterone and 5α-androstanedione. No differences in metabolism of [7α-3H]dehydroepiandrosterone or [4-14C]pregnenolone were detected between adrenal tissue from Sprague–Dawley, Wistar and Osborne–Mendel rats, but experiments with the Snell rat adrenocortical tumour 494 showed that this tissue had low 5α-reductase activity. In contrast, the major products of [7α-3H]dehydroepiandrosterone metabolism by mouse adrenal tissue were 5β-reduced steroids. Differences were observed between LACA and NH strains of mice in that there was a lower metabolism of androstenedione by NH mouse adrenal and a considerable difference in the proportions of aetiocholanolone and epiaetiocholanolone produced.

scholarly journals Adrenal microsomal C19-steroid 5α-reductase activity in the Snell transplantable rat adrenocortical tumour 494 and the effect of oestradiol, testosterone propionate and adrenocorticotrophin in intact and gonadectomized rats

1973 ◽  
Vol 132 (2) ◽  
pp. 293-300 ◽  
Author(s):  
Paul V. Maynard ◽  
Euan H. D. Cameron
Keyword(s):  
Enzyme Activity ◽  
Steroid Hormones ◽  
Microsomal Fraction ◽  
Testosterone Propionate ◽  
Reductase Activity ◽  
Intact Control ◽  
Adrenal Tissue ◽  
Males And Females ◽  
Adrenocortical Tumour ◽  
Hormonal Treatments

The C19-steroid 5α-reductase activity in the microsomal fraction of rat adrenal tissue under various hormonal treatments was examined. In intact control rats the activity is similar in both males and females, and after gonadectomy it is markedly increased. Treatment with oestradiol (150μg/day per animal for 7 days) or testosterone propionate (2mg/day per animal for 7 days) lowered the activity of 5α-reductase in castrated animals to approximately the values for intact animals in both sexes, and in intact animals the activity was also decreased by these treatments. The enzyme activity was also decreased by adrenocorticotrophin treatment but to a lesser extent than by the steroid hormones. The activity of the 5α-reductase enzyme in the Snell adrenocortical tumour 494 is very low when incubated as a whole homogenate, but the activity in microsomal material of the tumour was measured and unexpectedly found to be similar to that in intact controls.

scholarly journals In Vivo Bioavailability of Selenium in Selenium-Enriched Streptococcus thermophilus and Enterococcus faecium in CD IGS Rats

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 463
Author(s):  
Gabriela Krausova ◽  
Antonin Kana ◽  
Marek Vecka ◽  
Ivana Hyrslova ◽  
Barbora Stankova ◽  
...  
Keyword(s):  
Glutathione Reductase ◽  
Enterococcus Faecium ◽  
Reductase Activity ◽  
Streptococcus Thermophilus ◽  
Heart Tissue ◽  
Sprague Dawley ◽  
Glutathione Reductase Activity ◽  
Novel Concept ◽  
The Individual

The selenium (Se) enrichment of yeasts and lactic acid bacteria (LAB) has recently emerged as a novel concept; the individual health effects of these beneficial microorganisms are combined by supplying the essential micronutrient Se in a more bioavailable and less toxic form. This study investigated the bioavailability of Se in the strains Enterococcus faecium CCDM 922A (EF) and Streptococcus thermophilus CCDM 144 (ST) and their respective Se-enriched forms, SeEF and SeST, in a CD (SD-Sprague Dawley) IGS rat model. Se-enriched LAB administration resulted in higher Se concentrations in the liver and kidneys of rats, where selenocystine was the prevalent Se species. The administration of both Se-enriched strains improved the antioxidant status of the animals. The effect of the diet was more pronounced in the heart tissue, where a lower glutathione reductase content was observed, irrespective of the Se fortification in LAB. Interestingly, rats fed diets with EF and SeEF had higher glutathione reductase activity. Reduced concentrations of serum malondialdehyde were noted following Se supplementation. Diets containing Se-enriched strains showed no macroscopic effects on the liver, kidneys, heart, and brain and had no apparent influence on the basic parameters of the lipid metabolism. Both the strains tested herein showed potential for further applications as promising sources of organically bound Se and Se nanoparticles.

scholarly journals American trypanosomiasis (Chagas' disease) in conventional and germfree rats and mice

1987 ◽  
Vol 29 (5) ◽  
pp. 284-288 ◽  
Author(s):  
Marcelo E. Silva ◽  
Elizio A. Evangelista ◽  
Jacques R. Nicoli ◽  
Eduardo A. Bambirra ◽  
Enio C. Vieira
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Cardiac Failure ◽  
Sprague Dawley ◽  
American Trypanosomiasis ◽  
Sprague Dawley Rats ◽  
Rats And Mice ◽  
Germfree Rats

Germfree (GF) and conventional (CV) CFW (LOB) mice and Wistar and Sprague-Dawley rats were infected with Trypanosoma cruzi. The disease was more severe in the GF than in the CV animals as revealed by: (1) an earlier and more intense parasitemia; (2) a more precocious mortality; (3) a twice enlarged spleen: (4) a more intense cell and tissue parasitism; (5) visceral signs of cardiac failure.

Rosuvastatin treatment reverses impaired coronary artery vasodilation in fructose-fed, insulin-resistant rats

2004 ◽  
Vol 287 (1) ◽  
pp. R157-R160 ◽  
Author(s):  
Allison W. Miller ◽  
Christina D. Tulbert ◽  
David W. Busija
Keyword(s):  
Coronary Arteries ◽  
Fasting Insulin ◽  
Sprague Dawley ◽  
Calcium Dependent ◽  
Insulin Resistant ◽  
Functional Studies ◽  
Sprague Dawley Rats ◽  
Normal Rat ◽  
Biochemical Measurements

Insulin resistance (IR) impairs vascular responses in coronary arteries, but mechanisms of dysfunction and approaches to treatment remain unclear. We examined the ability of a new 3-hydroxy-methylglutaryl coenzyme A reductase inhibitor, rosuvastatin, to reverse reduced dilator responses in rats made IR by feeding a fructose-rich diet (FF). Sprague-Dawley rats were randomized to control (normal rat diet) or FF. After 1 wk, rats received rosuvastatin (2 mg/kg) or placebo (saline) subcutaneously for 5 wk. Biochemical measurements and in vitro functional studies of small coronary arteries were performed. Fasting insulin and triglyceride (TG) levels were markedly increased in FF-placebo rats compared with other groups. Rosuvastatin treatment of FF rats normalized TG and modestly decreased insulin levels. ACh-induced dilator responses were depressed in arteries from FF-placebo rats. This impairment was due to decreased responses via calcium-dependent K channels (KCa). Rosuvastatin treatment of FF rats completely reversed the response to ACh to normal levels. Moreover, this recovery in function was due to an improvement in vasodilation via KCa. Thus rosuvastatin treatment of IR rats normalizes coronary vascular dilator responses by improving the KCa function.

scholarly journals Seoritae Extract Reduces Prostate Weight and Suppresses Prostate Cell Proliferation in a Rat Model of Benign Prostate Hyperplasia

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hoon Jang ◽  
Woong-Jin Bae ◽  
Seung-Mo Yuk ◽  
Dong-Seok Han ◽  
U-Syn Ha ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Rat Model ◽  
Reductase Activity ◽  
Sprague Dawley ◽  
Prostate Hyperplasia ◽  
Prostate Cell ◽  
Beneficial Effects ◽  
Prostate Weight ◽  
Sprague Dawley Rats ◽  
Health Promoting

Seoritae is a type of black soybean that is known to have health-promoting effects due to its high isoflavone and anthocyanin contents. We evaluated whether Seoritae extract (SE) had beneficial effects on the reduction of prostate weight in a rat model of benign prostatic hyperplasia (BPH). BPH was induced by intramuscular injections of testosterone enanthate once a week for 5 weeks in Sprague-Dawley rats, and rats were treated with or without daily oral doses of SE during BPH induction. After 5 weeks, the oxidative stress (superoxide dismutase and 8-hydroxy-2-deoxyguanosine), apoptosis (caspase-3), and activity of 5-alpha reductase were evaluated in the serum and prostate. The SE treatment group showed a significant decrease in prostate weight, oxidative stress, apoptosis, and 5-alpha reductase activity compared to the nontreated BPH group. These results show that SE is effective in decreasing the weight and proliferation of the prostate, and suggest that SE may be an effective treatment for BPH.

Albumin/Globulin Ratios, Colloid Osmotic Pressures and Lowry Protein Microanalysis in Rat Plasma

1978 ◽  
Vol 55 (6) ◽  
pp. 529-532 ◽  
Author(s):  
D. Weller ◽  
S. Azar ◽  
M. A. Johnson ◽  
M. Azar
Keyword(s):  
Osmotic Pressure ◽  
Experimental Situation ◽  
Rat Plasma ◽  
Colloid Osmotic Pressure ◽  
Sprague Dawley ◽  
Spontaneously Hypertensive ◽  
Normal Rat ◽  
Genetic Strains ◽  
The Difference ◽  
Capillary Pressures

1. We have correlated measurements of colloid osmotic pressure with protein concentrations and albumin/globulin ratios. Plasma from normal rats of different genetic strains was used. 2. The Landis and Pappenheimer equation does not accurately predict colloid osmotic pressure properties of the normal rat plasma used, which had an albumin/globulin ratio of 0.74. Over the range 2.2−12.2 g of protein/100 ml, the measured colloid osmotic pressures vary between −5% and +10% from the value predicted by the equation. 3. In Wistar-derived genetically hypertensive and normotensive rats, albumin/globulin ratios were higher than those in common Wistar rats. Owing to the presence of higher globulins, plasma proteins were higher in Wistar than spontaneously hypertensive and normotensive rats, and colloid osmotic pressure was identical in the three groups. 4. When common Sprague—Dawley rats were obtained from two different suppliers, their albumin/globulin ratios were found to be different. 5. As the difference in albumin/globulin ratio between human and rat plasma becomes more pronounced, predicting rat plasma colloid osmotic pressure from the Landis and Pappenheimer equation becomes less accurate. Environmental and/or genetic factors play a role in the albumin/globulin ratio found in normal healthy rats. 6. Therefore albumin/globulin ratios should be measured in each experimental situation. If the ratios are close to that of human plasma, the Landis and Pappenheimer equation can be used. If not, a new colloid osmotic pressure-protein expression should be derived. 7. Calculation of glomerular capillary pressures from directly measured colloid osmotic pressure values reduces error.

Response of adrenal 3β-hydroxy-Δ5-steroid dehydrogenase to adrenocorticotropin treatment in thiouracil-fed male mice

1982 ◽  
Vol 60 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Lee A. Meserve ◽  
Shu-Mei Ting
Keyword(s):  
Maternal Diet ◽  
Subcutaneous Administration ◽  
Physiological Saline ◽  
Subcutaneous Injections ◽  
Adrenal Tissue ◽  
Endocrine Status ◽  
Elevated Activity ◽  
Rats And Mice ◽  
Old Mice ◽  
Steroid Dehydrogenase

A number of parallels can be drawn between the reported endocrine status of thiouracil-fed young rodents and that of aged animals, particularly with regard to the hypothalamus–pituitary–adrenal axis. Since the activity of the adrenal steroidogenic enzyme 3β-hydroxy-Δ5-steroid dehydrogenase (3β-HSD) has been shown to be depressed in aged rats and mice, the present study was done to determine whether exposure of young mice to thiouracil had a similar effect on adrenal 3β-HSD activity. Feeding the goitrogen thiouracil at 0.25% (w/w) of the maternal diet from conception, and keeping it 0.25% of the offsprings diet after weaning, significantly elevated activity of 3β-HSD per gram of adrenal gland above control levels in 4-month-old mice, perhaps to compensate for depressed adrenal mass. Daily subcutaneous injections of physiological saline (0.9%) for 4 days was sufficient to increase 3β-HSD activity per gram of adrenal tissue in euthyroid (P < 0.05) but not in thiouracil-fed mice. Subcutaneous administration of ACTH (2 IU daily for 4 days) significantly increased adrenal 3β-HSD activity to comparable levels in thiouracil-fed and euthyroid animals. Thus, thiouracil enhances the activity of 3β-HSD per gram of adrenal tissue and does not prevent response of enzyme activity to exogenous ACTH.

scholarly journals ADP-ribosyl cyclase and ryanodine receptors mediate endothelin ETA and ETB receptor-induced renal vasoconstriction in vivo

2008 ◽  
Vol 295 (2) ◽  
pp. F360-F368 ◽  
Author(s):  
Tiffany L. Thai ◽  
William J. Arendshorst
Keyword(s):  
Ryanodine Receptors ◽  
Ruthenium Red ◽  
Sprague Dawley ◽  
Renal Vasculature ◽  
Receptor Stimulation ◽  
Renal Vasoconstriction ◽  
Adp Ribosyl Cyclase ◽  
Etb Receptor ◽  
Rats And Mice

ADP-ribosyl cyclase (ADPR cyclase) and ryanodine receptors (RyR) participate in calcium transduction in isolated afferent arterioles. We hypothesized that this signaling pathway is activated by ETA and ETB receptors in the renal vasculature to mediate vasoconstriction in vivo. To test this, we measured acute renal blood flow (RBF) responses to ET-1 in anesthetized rats and mice in the presence and absence of functional ADPR cyclase and/or RyR. Inhibitors of ADPR cyclase (nicotinamide) or RyR (ruthenium red) reduced RBF responses to ET-1 by 44% ( P < 0.04 for both) in Sprague-Dawley rats. Mice lacking the predominant form of ADPR cyclase (CD38−/−) had RBF responses to ET-1 that were 47% weaker than those seen in wild-type mice ( P = 0.01). Selective ETA receptor stimulation (ET-1+BQ788) produced decreases in RBF that were attenuated by 43 and 56% by nicotinamide or ruthenium red, respectively ( P < 0.02 for both). ADPR cyclase or RyR inhibition also reduced vasoconstrictor effects of the ETB receptor agonist sarafotoxin 6c (S6c; 77 and 54%, respectively, P < 0.02 for both). ETB receptor stimulation by ET-1 + the ETA receptor antagonist BQ123 elicited responses that were attenuated by 59 and 60% by nicotinamide and ruthenium red, respectively ( P < 0.01 for both). Nicotinamide attenuated RBF responses to S6c by 54% during inhibition of nitric oxide synthesis ( P = 0.001). We conclude that in the renal microcirculation in vivo 1) ET-1-induced vasoconstriction is mediated by ADPR cyclase and RyR; 2) both ETA and ETB receptors activate this pathway; and 3) ADPR cyclase participates in ETB receptor signaling independently of NO.

Oxytocin resistance in Brattleboro rat adipocytes and comparative studies on insulin or oxytocin responsiveness in normal rat adipocytes

1983 ◽  
Vol 61 (11) ◽  
pp. 1418-1425 ◽  
Author(s):  
K. Hanif ◽  
H. J. Goren ◽  
R. M. Geonzon ◽  
K. Lederis ◽  
M. D. Hollenberg
Keyword(s):  
Calcium Concentration ◽  
Maximal Response ◽  
Sprague Dawley ◽  
Assay Medium ◽  
Rat Adipocytes ◽  
Sprague Dawley Rats ◽  
Normal Rat ◽  
Increased Sensitivity ◽  
Long Evans ◽  
Treatment Use

We have evaluated factors, other than genetic, which might be related to the lack of an oxytocin-mediated insulinlike response (glucose oxidation; lipogenesis) in adipocytes from Brattleboro rats, homozygous for the diabetes insipidus trait (HoDI rats). The manoeuvres used in an attempt to restore the glucoregulatory responses to oxytocin in HoDI cells (increased glucose in the fat pad digestion medium; increased calcium concentration in the oxidation assay; estrogen treatment; use of [1-14C]glucose as substrate; inclusion of adenosine in the assay medium; vasopressin replacement therapy) uniformly failed to result in oxytocin activation of HoDI adipocytes, in contrast, the contractile responses of estrogenized HoDI rat uteri were indistinguishable from those of estrogenized normal rats. We conclude that the nonresponsiveness of the Brattleboro adipocytes to the glucoregulatory actions of oxytocin is not due to factors related to the conditions of the bioassay. On the other hand, in normal fat cells (from Sprague–Dawley and Long Evans rats), oxytocin responsiveness was augmented by a number of the manoeuvres mentioned above, most notably by the inclusion of either calcium (10 mM) or adenosine (10 μM) in the assay medium. Nonetheless, the maximum oxytocin responsiveness of adipocytes from Long Evans or Sprague–Dawley rats, under all conditions of assay, was still only a fraction (less than 20%) of the maximal response to insulin. The effect of adenosine on oxytocin action (increased sensitivity, without an effect on the maximum response) is in keeping with the previously observed effects of this nucleoside on the action of insulin; our results thus pointed to a new parallel in the action of insulin and oxytocin.

Inability of human clinical strains of Helicobacter pylori to colonize the alimentary tract of germfree rodents

1990 ◽  
Vol 36 (4) ◽  
pp. 237-241 ◽  
Author(s):  
Margherita T. Cantorna ◽  
Edward Balish
Keyword(s):  
Helicobacter Pylori ◽  
Lymph Nodes ◽  
Alimentary Tract ◽  
Sprague Dawley ◽  
Mesenteric Lymph Nodes ◽  
Immunodeficient Mice ◽  
Mesenteric Lymph ◽  
H Pylori ◽  
Rats And Mice ◽  
Culture Negative

Several attempts were made to colonize the alimentary tract and infect germfree BALB/c mice and germfree Sprague-Dawley rats with two human isolates of Helicobacter pylori. The alimentary tracts of mice, sacrificed at intervals between 1 day and 20 weeks after oral challenge, were culture negative for H. pylori. The alimentary tract, kidney, liver, and mesenteric lymph nodes were culture negative for H. pylori 5 h after intravenous challenge. Growth of H. pylori was inhibited by homogenates of murine stomach, small intestine, liver, and mesenteric lymph nodes. Germfree rats and mice do not appear to be readily colonized or infected by human strains of H. pylori. Key words: Helicobacter pylori, germfree mice, congenitally immunodeficient mice.

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