Effects of androgens on bioactivity and immunoreactivity of pituitary FSH in GnRH antagonist-treated male rats

1990 ◽  
Vol 122 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Om P. Sharma ◽  
Shafiq A. Khan ◽  
Gerhard F. Weinbauer ◽  
Mohammed Arslan ◽  
Eberhard Nieschlag
Keyword(s):  
Isoelectric Focusing ◽  
Gnrh Antagonist ◽  
Molecular Composition ◽  
Male Rats ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Combined Administration ◽  
Ph Range ◽  
Fsh Bioactivity

Abstract The effects of androgens on the bioactivity and molecular composition of pituitary FSH were examined in intact and GnRH antagonist-suppressed male rats. Eight groups of adult Sprague-Dawley rats were subjected to the following treatments: antagonist (75 μg/day by osmotic minipumps; sc), testosterone-filled Silastic implants (3×5 cm, sc), dihydrotestosterone-filled Silastic implants (3×5 cm, sc), E2 benzoate (15 μg/day, sc), and combined administration of antagonist with either steroid for 3 weeks. At the end of the treatment period, pituitaries were dissected out and homogenised. FSH content was determined in the pituitary extracts by an in vitro bioassay and a radioimmunoassay. Individual pituitary extracts from rats treated with vehicle, testosterone and testosterone + antagonist were subjected to isoelectric-focusing on sucrose density gradients performed in the pH range from 3.5 to 7.0. Individual isoelectric-focusing fractions (100-120) were analysed for bioactive and immunoreactive FSH. Treatment with antagonist, E2 or antagonist + E2 caused a significant decrease in pituitary FSH, whereas testosterone and dihydrotesterone alone or in combination with antagonist prevented the decrease in pituitary FSH. The effects of all treatments on both bioactive and immunoreactive FSH were similar. Testosterone treatment not only maintained FSH synthesis but also altered the molecular composition of pituitary FSH. Following treatment with testosterone there was a shift of maximal FSH bioactivity to the more acidic pH range. On the other hand, less bioactivity was recovered than corresponding immunoreactivity in the higher pH region, resulting in significantly reduced ratios of bioactivity to immunoreactivity of FSH. No significant differences were found in the isoelectric-focusing profiles or bioactivity to immunoreactivity ratios of pituitary FSH in animals treated with testosterone alone or in combination with antagonist. The results demonstrate that testosterone not only maintained the synthesis of both bioactive and immunoreactive FSH in male rats, but also influences the molecular composition of pituitary FSH. These effects of testosterone on pituitary FSH appear not to be mediated through hypothalamic GnRH.

scholarly journals Vitamin B12 Conjugation of Peptide-YY3–36 Decreases Food Intake Compared to Native Peptide-YY3–36 Upon Subcutaneous Administration in Male Rats

Endocrinology ◽  
2015 ◽  
Vol 156 (5) ◽  
pp. 1739-1749 ◽  
Author(s):  
Kelly E. Henry ◽  
Clinton T. Elfers ◽  
Rachael M. Burke ◽  
Oleg G. Chepurny ◽  
George G. Holz ◽  
...  
Keyword(s):  
Food Intake ◽  
Vitamin B12 ◽  
Day Treatment ◽  
Subcutaneous Administration ◽  
Male Rats ◽  
Sprague Dawley ◽  
In Vivo Experiments ◽  
Sprague Dawley Rats

Challenges to peptide-based therapies include rapid clearance, ready degradation by hydrolysis/proteolysis, and poor intestinal uptake and/or a need for blood brain barrier transport. This work evaluates the efficacy of conjugation of vitamin B12 (B12) on sc administered peptide tyrosine tyrosine (PYY)3–36 function. In the current experiments, a B12-PYY3–36 conjugate was tested against native PYY3–36, and an inactive conjugate B12-PYYC36 (null control) in vitro and in vivo. In vitro experiments demonstrated similar agonism for the neuropeptide Y2 receptor by the B12-PYY3–36 conjugate (EC50 26.5 nM) compared with native PYY3–36 (EC50 16.0 nM), with the null control having an EC50 of 1.8 μM. In vivo experiments were performed in young adult male Sprague Dawley rats (9 wk). Daily treatments were delivered sc in five 1-hour pulses, each pulse delivering 5–10 nmol/kg, by implanted microinfusion pumps. Increases in hindbrain Fos expression were comparable 90 minutes after B12-PYY3–36 or PYY3–36 injection relative to saline or B12-PYYC36. Food intake was reduced during a 5-day treatment for both B12-PYY3–36- (24%, P = .001) and PYY3–36-(13%, P = .008) treated groups relative to baseline. In addition, reduction of food intake after the three dark cycle treatment pulses was more consistent with B12-PYY3–36 treatment (−26%, −29%, −27%) compared with the PYY3–36 treatment (−3%, −21%, −16%), and B12-PYY3–36 generated a significantly longer inhibition of food intake vs PYY3–36 treatment after the first two pulses (P = .041 and P = .036, respectively). These findings demonstrate a stronger, more consistent, and longer inhibition of food intake after the pulses of B12-PYY3–36 conjugate compared with the native PYY3–36.

scholarly journals The Effects of Tris(2,3-Dibromopropyl)Phosphate on the Reproductive System of Male Rats

1986 ◽  
Vol 5 (2) ◽  
pp. 153-160
Author(s):  
R. C. Cochran ◽  
M. A. Wiedow
Keyword(s):  
Reproductive System ◽  
Sperm Storage ◽  
Seminal Vesicles ◽  
Male Rats ◽  
Serum Concentrations ◽  
Sperm Production ◽  
Sprague Dawley ◽  
Prostate Weight ◽  
Sprague Dawley Rats

Tris(2,3-dibromopropyl)phosphate (TRIS) administered intraperitoneally to adult, male Sprague-Dawley rats for 12 weeks at concentrations of 85.1 to 340.5 mg/week caused significant, dose-related declines in the weights of the testes, epididymides, and seminal vesicles. Sperm production by the testes and sperm storage in the epididymides were also reduced. Although prostate weight declined, the effect was not correlated with the dose of TRIS. Neither serum concentrations of testosterone nor the testicular capacity to produce testosterone in vitro were affected by any dose of TRIS.

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.

scholarly journals Stamina-Enhancing Effects of Human Adipose-Derived Stem Cells

2021 ◽  
Vol 30 ◽  
pp. 096368972110354
Author(s):  
Eun-Jung Yoon ◽  
Hye Rim Seong ◽  
Jangbeen Kyung ◽  
Dajeong Kim ◽  
Sangryong Park ◽  
...  
Keyword(s):  
Physical Activity ◽  
Stem Cells ◽  
Locomotor Activity ◽  
Tissue Injury ◽  
Male Rats ◽  
Adipose Derived Stem Cells ◽  
Sprague Dawley ◽  
Serum Triglycerides

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.

scholarly journals Pharmacological comparison of four biopolymeric natural gums as hemostatic agents for management of bleeding wounds: preliminary in vitro and in vivo results

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Himanshu Kushwah ◽  
Nidhi Sandal ◽  
Meenakshi Chauhan ◽  
Gaurav Mittal
Keyword(s):  
Xanthan Gum ◽  
Guar Gum ◽  
Human Lymphocytes ◽  
Sprague Dawley ◽  
Gum Tragacanth ◽  
Civilian Trauma ◽  
Sprague Dawley Rats ◽  
Cytotoxicity Studies

Abstract Background Uncontrolled bleeding is one of the primary reasons for preventable death in both civilian trauma and military battle field. This study evaluates in vitro and in vivo hemostatic potential of four biopolymeric natural gums, namely, gum tragacanth, guar gum, xanthan gum, and gum acacia. In vitro evaluation of whole blood clotting time and erythrocyte agglutination assay were carried out. In vitro cytotoxicity studies with respect to each gum were done in human lymphocytes to ascertain percent cell viability. In vivo hemostatic potential of each gum (as sponge dressing and powder form) was evaluated in Sprague Dawley rats using tail bleeding assay and compared with commercially available hemostatic sponge. Other important parameters like (a) time taken for complete hemostasis, (b) amount of blood absorbed, (c) adherence strength of developed hemostatic dressing(s), (d) incidence of re-bleeding, and (e) survival of animals were also studied. Results Of the four test gums studied, xanthan gum (@3mg/ml of blood) and gum tragacanth (@35mg/ml of blood) were able to clot blood in least time (58.75±6.408 s and 59.00±2.082 s, respectively) and exhibited very good hemostatic potential in vitro. Except for xanthan gum, all other test gums did not exhibit any significant cytotoxicity at different time points till 24 h. In rat tail bleeding experiments, gum tragacanth sponge dressing and powder achieved hemostasis in least time (156.2±12.86 s and 76±12.55 s, respectively) and much earlier than commercially available product (333.3±38.84 s; p˂0.01). Conclusion Results indicate potential of gum tragacanth to be developed into a suitable hemostatic product.

Bioavailability in Vivo of Benzo[a]Pyrene Adsorbed to Diesel Particulate

1991 ◽  
Vol 7 (3) ◽  
pp. 125-139 ◽  
Author(s):  
David R. Bevan ◽  
David M. Ruggio
Keyword(s):  
Health Risks ◽  
Quantitative Description ◽  
Intratracheal Instillation ◽  
Direct Analysis ◽  
Sprague Dawley ◽  
Reasonable Estimate ◽  
Diesel Particulate ◽  
Sprague Dawley Rats

To evaluate health risks associated with exposure to particulates in the environment, it is necessary to quantify the bioavailability of carcinogens associated with the particulates. Direct analysis of bioavailability in vivo is most readily accomplished by adsorbing a radiolabeled form of the carcinogen to the particulate. A sam ple of native diesel particulate collected from an Oldsmobile die sel engine that contained 1.03 μ g benzo[ a] pyrene ( BaP)/ g particulate was supplemented with exogenous [ 3 H]- BaP to pro duce a particulate containing 2.62 μ g BaP/g. To insure that elu tion of BaP from native and [3 H] -BaP-supplemented particulate was similar, in vitro analyses were performed. When using phos pholipid vesicles composed of dimyristoylphosphatidylcholine (DMPC), 1.52% of total BaP was eluted from native particulate into the vesicles in 18 hrs; from [ 3 H] -BaP supplemented particu late, 1.68% was eluted. Using toluene as eluent, 2.55% was eluted from native particulate, and 8.25% from supplemented particulate, in 6 hrs. Supplemented particulate was then instilled intratracheally into male Sprague-Dawley rats and distribution of radioactivity was analyzed at selected times over 3 days. About 50% of radioactivity remained in lungs at 3 days following instil lation, with 30% being excreted into feces and the remainder dis tributed throughout the organs of the rats. To estimate the amount of radioactivity that entered feces through swallowing of a portion of the instilled dose, [3 H] -BaP-supplemented particu late was instilled intratracheally into rats that had a cannula sur gically implanted in the bile duct. Rate of elimination of radio activity into bile was monitored; 10.6% of radioactivity was re covered in 6 hr, an amount slightly lower than the 12.8% ex creted in 6 hrs into feces of animals with intact bile ducts. Our studies provide a quantitative description of the distribution of BaP and its metabolites following intratracheal instillation of diesel particulate. Because rates of elution of BaP in vitro are similar for native diesel particulate and particulate with supple mental [ 3H] -BaP, our results provide a reasonable estimate of the bioavailability in vivo of BaP associated with diesel particu late.

Safety Assessment of a Hydroethanolic Extract of Caralluma fimbriata

2013 ◽  
Vol 32 (5) ◽  
pp. 385-394 ◽  
Author(s):  
Antoinette Y. Odendaal ◽  
Narendra S. Deshmukh ◽  
Tennille K. Marx ◽  
Alexander G. Schauss ◽  
John R. Endres ◽  
...  
Keyword(s):  
Developmental Toxicity ◽  
Toxicity Study ◽  
Developmental Study ◽  
Sprague Dawley ◽  
Oral Toxicity ◽  
Toxicological Assessment ◽  
Sprague Dawley Rats ◽  
Chromosomal Aberration Test ◽  
Hydroethanolic Extract

This toxicological assessment evaluated the safety of a hydroethanolic extract prepared from Caralluma fimbriata (CFE), a dietary supplement marketed worldwide as an appetite suppressant. Studies included 2 in vitro genotoxicity assays, a repeated dose oral toxicity study, and a developmental study in rats. No evidence of in vitro mutagenicity or clastogenicity surfaced in the in vitro studies at concentrations up to 5000 μg of extract/plate (Ames test) or 5000 μg of extract/mL (chromosomal aberration test). No deaths or treatment-related toxicity were seen in the 6-month chronic oral toxicity study in Sprague-Dawley rats conducted at 3 doses (100, 300, and 1000 mg/kg body weight (bw)/d). The no observed effect level for CFE in this study was considered to be 1000 mg/kg bw/d. A prenatal developmental toxicity study conducted at 3 doses (250, 500, and 1000 mg/kg bw/d) in female Sprague-Dawley rats resulted in no treatment-related external, visceral, or skeletal fetal abnormalities, and no treatment-related maternal or pregnancy alterations were seen at and up to the maximum dose tested. CFE was not associated with any toxicity or adverse events.

Neonatal IL-4 exposure decreases adipogenesis of male rats into adulthood

2021 ◽  
Author(s):  
Tammy Ying ◽  
Thea N. Golden ◽  
Lan Cheng ◽  
Jeff Ishibashi ◽  
Patrick Seale ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Neonatal Period ◽  
Uncoupling Protein ◽  
Adipogenic Differentiation ◽  
Male Rats ◽  
Interleukin 4 ◽  
Sprague Dawley ◽  
Fat Cell ◽  
Subcutaneous White Adipose Tissue

The cytokine interleukin 4 (IL-4) can increase beige adipogenesis in adult rodents. However, neonatal animals use a distinct adipocyte precursor compartment for adipogenesis compared to adults. In this study, we address whether IL-4 can induce persistent effects on adipose tissue when administered subcutaneously in the interscapular region during the neonatal period in Sprague Dawley rats. We injected IL-4 into neonatal male rats during postnatal days 1-6, followed by analysis of adipose tissue and adipocyte precursors at 2 weeks and 10 weeks of age. Adipocyte precursors were cultured and subjected to differentiation in vitro. We found that a short and transient IL-4 exposure in neonates upregulated uncoupling protein 1 (Ucp1) mRNA expression and decreased fat cell size in subcutaneous white adipose tissue (WAT). Adipocyte precursors from mature rats that had been treated with IL-4 as neonates displayed a decrease in adiponectin (Adipoq) but no change in Ucp1 expression, as compared to controls. Thus, neonatal IL-4 induces acute beige adipogenesis and decreases adipogenic differentiation capacity long term. Overall, these findings indicate that the neonatal period is critical for adipocyte development and may influence the later onset of obesity.

Metabolism of triallate in Sprague-Dawley rats. 3. In vitro metabolic pathways

1993 ◽  
Vol 41 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Amy G. Hackett ◽  
John J. Kotyk ◽  
Hideji. Fujiwara ◽  
Eugene W. Logusch
Keyword(s):  
Metabolic Pathways ◽  
Sprague Dawley ◽  
Sprague Dawley Rats
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