Selective alterations in hepatic nuclear T3-receptors and enzyme responses by glucocorticoid deficit or excess

1983 ◽  
Vol 104 (4) ◽  
pp. 485-489 ◽  
Author(s):  
Alfredo R. Recúpero ◽  
Aldo H. Coleoni ◽  
Olga Cherubini ◽  
Adriana Oviedo

Abstract. Glucocorticoid deficit in rats induced by adrenalectomy for a 10-day period resulted in an increase in the apparent association constant (Ka) of the liver nuclear T3-receptor while maximal binding capacity (MBC) remained unaltered compared to the intact (sham-operated) animals and to adrenalectomy plus dexamethasone (Sx + D) animals. In addition, a significant increase in the basal activity of liver mitochondrial α-glycerophosphate dehydrogenase (α-GPD) was observed, while cytosolic malic enzyme (ME) activity was not modified in this situation. Dexamethasone injection (5 mg/kg/day for 4–5 days) to previously adrenalectomized animals (Sx + D) induced a significant increase in MBC of nuclear T3-receptors. On the other hand, Ka value and α-GPD activity were restored to the values found in the control group. However, basal activity of ME as well as the response of this enzyme to a saturating dose of T3 was substantially increased by dexamethasone treatment. A non-specific in vitro effect of dexamethasone on MBC and ME was excluded as these parameters were not modified when dexamethasone was added immediately before the in vitro assays. The present study indicates that glucocorticoid deficit or excess is able to induce changes at the level of the nuclear T3-receptor site. The increase in the activity of cytolic ME induced by dexamethasone injection was associated with a simultaneous

2009 ◽  
Vol 76 (2) ◽  
Author(s):  
M.S. Masgoret ◽  
C.J. Botha ◽  
J.G. Myburgh ◽  
T.W. Naude ◽  
L. Prozesky ◽  
...  

During the mid 1990s a potentially serious, chronic syndrome was reported in well-managed beef and dairy herds from unrelated parts of South Africa. Farmers reported that it manifested as various combinations of decreased production, decreased weaning masses, apparent immune breakdown in previously immunocompetent animals, increased reproductive disorders, various mineral imbalances in non-deficient areas and goitre, noticeable as enlarged thyroid glands. The farmers associated this syndrome with certain batches of sugar cane molasses and molasses-based products. The syndrome was reminiscent of an ''endocrine disruptive syndrome''. The objective of this study was to evaluate the suspected endocrine disruptive effect of molasses included in cattle feed. Using existing in vitro assays, four batches of molasses syrup were screened for possible inclusion in a calf feeding trial. Two batches were selected for the trial. Thirty-two, 4- to 6-week-old, weaned Holstein bull calves were included in the single phase, three treatment, parallel design experiment. In two of the groups of calves, two different batches of molasses were included in their rations respectively. The control group was fed a ration to which no molasses was added, but which was balanced for energy and mineral content. The mass gain of the calves was recorded over the 6-month study period. The calves were clinically examined every week and clinical pathology parameters, immune responses and endocrine effects were regularly evaluated. Even though endocrine disrupting effects were detected with the in vitro screening assays, these could not be reproduced in the calves in the experiment. The two batches of molasses utilized in the calf feeding trial did not induce major differences in any of the parameters measured, with the exception of a lower mass gain in one of the molasses-fed groups (Group 1), which tended towards significance. The results of the study indicate that the two batches of molasses had no endocrine disruptive or immunosuppressive effects in calves.


1980 ◽  
Vol 95 (4) ◽  
pp. 495-499 ◽  
Author(s):  
Kazumasa Ishiguro ◽  
Yukichi Suzuki ◽  
Tamotu Sato

Abstract. Changes of nuclear T3 receptors during brain maturation were studied in normal and hypothyroid rats. In normal rats, the higher receptor concentration present in the neonatal period (0.35 ± 0.04 ng T3/mg DNA) decreased at the age of 14 days (0.25 ± 0.02 ng T3/mg DNA), and remained at this level thereafter to 35 days of age (0.25 ± 0.03 T3/mg DNA). In contrast, hypothyroid rats showed a significantly higher concentration than that found in an age-matched control group at the age of 14 days (0.38 ± 0.07 ng T3/mg DNA), and maintained this level up to 35 days of age (0.37 ± 0.03 T3/mg DNA). The binding affinity was similar in both groups and throughout maturation (mean ± sd in normal groups: 1.9 ± 0.3 × 1010m−1, in hypothyroid groups: 1.7 ± 0.2 × 1010m−1). Plasma T3 concentrations showed changes reciprocal to those in the binding capacity of T3 receptors. These results indicate that nuclear T3 receptors in rat brain mature by the age of 14 days, in association with a decrease in binding capacity, and this process seems to be T3-dependent. The physiological role of the high concentration of T3 receptors observed in neonatal and hypothyroid rat brain during development is at present not clear.


2020 ◽  
Vol 44 (5) ◽  
pp. 342-347
Author(s):  
Natyla ML Silva ◽  
Victor G Costa ◽  
Letícia M Gonçalves ◽  
Isabella A Gomes ◽  
Marco Aurélio B Paschoal

Objective: The present study investigated the erosive potential of children’s mouthrinses on glass ionomer cement (GIC) samples after simulated toothbrushing. Study design: Forty round-shaped samples of GIC were divided into 3 groups: G1- cetylpyridinium chloride, G2- xylitol and triclosan and G3–Malva sylvestris and xylitol and G4–distilled water as a control group. Prior to the main tests, the samples were submitted to the surface roughness measurement (Ra) and weight analysis (W). Afterward, they were brushed twice day (2× / day) for 15 days and immersed in mouthrinses after the last daily brushing. The final surface roughness (R2) and weight (W2) were determined after completing the tooth brushing-mouth rinsing cycles and the real increase in roughness (ΔRa) and real weight loss (ΔW) were calculated. In addition, stereoscopic images taken at 30× magnification. The data was analyzed by one-way ANOVA and Tukey-test post hoc tests for intergroup comparison and the T-test for dependent samples (α = 0.05). Results: Only group G2 showed increased in roughness ΔRa (1.53 ± 0.94) whereas ΔW values were not significant. However, evident cracks and voids were verified for all tested children’s rinses. Conclusion: Thus, children’s mouthrinse containing xylitol / triclosan increased the GIC roughness, especially when associated with brushing.


2017 ◽  
Vol 67 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Sung-Suk Suh ◽  
Se Kyung Oh ◽  
Sung Gu Lee ◽  
Il-Chan Kim ◽  
Sanghee Kim

Abstract The main aim of the current research was to study the effect of porphyra-334, one of mycosporine-like amino acids (MAAs), well known as UV-absorbing compounds, on UVinduced apoptosis in human immortalized keratinocyte (HaCaT) cells. Due to their UV-screening capacity and ability to prevent UV-induced DNA damage, MAAs have recently attracted considerable attention in both industry and research in pharmacology. Herein, human HaCaT cells were used to determine the biological activities of porphyra- 334 by various in vitro assays, including proliferation, apoptosis and Western blot assays. The proliferation rate of UV-irradiated HaCaT cells was significantly decreased compared to the control group. Pretreatment with porphyra- 334 markedly attenuated the inhibitory effect of UV and induced a dramatic decrease in the apoptotic rate. Expression of active caspase-3 protein was increased in response to UV irradiation, while caspase-3 levels were similar between cells treated with porphyra-334 and the non-irradiated control group. Taken together, our data suggest that porphyra-334 inhibits UV-induced apoptosis in HaCaT cells through attenuation of the caspase pathway.


2021 ◽  
Author(s):  
Mi Han ◽  
Yi Cao ◽  
Wenjie Zhou ◽  
Mingjuan Zhou ◽  
Xiaowei Zhou ◽  
...  

Abstract Impaired endometrial receptivity is the main cause of recurrent implantation failure (RIF), however, its underlying mechanism is unclear. In this study, we found that HMGB1 expression was significantly decreased in the implantation phase endometrium in the control group (patients with tubal infertility who successfully achieved conception after the first embryo transfer) (P = 0.006). However, the expression levels of HMGB1 mRNA and protein were significantly upregulated during the implantation phase in endometrial tissues obtained from patients with RIF compared to those in the control group (P = 0.001), consistent with the results of genome-wide expression profiling. Moreover, in vitro assays showed that increased expression of HMGB1 in human endometrial epithelial cells cause marked deficiency in supporting blastocysts and human embryonic JAR cell adhesion, mimicking the process of embryo adhesion. However, overexpression of HMGB1 had no effect on cell proliferation and in-vitro decidualization in a human endometrial stromal cell line (T-HESCs) and in primary human endometrial stromal cells (HESCs). These findings indicate that increased HMGB1 levels suppressed the adhesion capability of epithelial cells, contributing to impaired endometrial receptivity in patients with recurrent implantation failure. This characteristic can be used as a target for detecting and treating recurrent implantation failure in clinical practice.


2014 ◽  
Vol 44 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Parya Rahnama Vosough ◽  
Ali Mohamadi Sani ◽  
Masoumeh Mehraban ◽  
Reza Karazhyan

Purpose – Since a sound detoxification method is needed for controlling aflatoxin B1 (AFB1), as one of the most harmful mycotoxins in animal production and food industry, this study was performed. The paper aims to discuss these issues. Design/methodology/approach – This study was conducted to examine the ability of Lactobacillus rhamnosus strain GG to remove AFB1 from liquid media. The binding of AFB1 to Lb. rhamnosus GG was studied for viable, heat-killed and acid-killed bacteria. AFB1 at concentrations (5, 10 and 20 μg/l) was added to the bacterial culture (109 cfu/ml) in MRS broth medium and incubated at 25°C for 4, 12 and 24 h. The aflatoxin-binding capacity of the strain was quantified by the amount of unbound AFB1 using ELISA technique. Findings – Results showed the AFB1-binding capacity of viable, heat-killed and acid-killed bacteria was about 43, 49 and 50 percent, respectively. The percentage of AFB1 removed was the highest amount in low (5 μg/l) and high (20 μg/l) concentrations, and there was no significant difference between them (p=0.05). These findings suggest that lactic acid bacteria can be exploited as an approach to detoxification of aflatoxins from foods. Practical implications – This method is safe because non-viable bacteria have more ability to remove toxin than viable bacteria, and also it is an effective method with 50 percent approximately toxin removal. Originality/value – Since there has been no research on the ability of this strain on the removal of AFB1, the authors assessed the ability of the strain in high levels of AFB1.


2020 ◽  
pp. 153537022096696
Author(s):  
Leonardo Lima Fuscaldi ◽  
Joaquim Teixeira de Avelar Júnior ◽  
Daniel Moreira dos Santos ◽  
Daiane Boff ◽  
Vívian Louise Soares de Oliveira ◽  
...  

In the continuing search for novel antibiotics, antimicrobial peptides are promising molecules, due to different mechanisms of action compared to classic antibiotics and to their selectivity for interaction with microorganism cells rather than with mammalian cells. Previously, our research group has isolated the antimicrobial peptide LyeTx I from the venom of the spider Lycosa erythrognatha. Here, we proposed to synthesize three novel shortened derivatives from LyeTx I (LyeTx I mn; LyeTx I mnΔK; LyeTx I mnΔKAc) and to evaluate their toxicity and biological activity as potential antimicrobial agents. Peptides were synthetized by Fmoc strategy and circular dichroism analysis was performed, showing that the three novel shortened derivatives may present membranolytic activity, like the original LyeTx I, once they folded as an alpha helix in 2.2.2-trifluorethanol and sodium dodecyl sulfate. In vitro assays revealed that the shortened derivative LyeTx I mnΔK presents the best score between antimicrobial (↓ MIC) and hemolytic (↑ EC50) activities among the synthetized shortened derivatives, and LUHMES cell-based NeuriTox test showed that it is less neurotoxic than the original LyeTx I (EC50 [LyeTx I mnΔK] ⋙ EC50 [LyeTx I]). In vivo data, obtained in a mouse model of septic arthritis induced by Staphylococcus aureus, showed that LyeTx I mnΔK is able to reduce infection, as demonstrated by bacterial recovery assay (∼10-fold reduction) and scintigraphic imaging (less technetium-99m labeled-Ceftizoxime uptake by infectious site). Infection reduction led to inflammatory process and pain decreases, as shown by immune cells recruitment reduction and threshold nociception increment, when compared to positive control group. Therefore, among the three shortened peptide derivatives, LyeTx I mnΔK is the best candidate as antimicrobial agent, due to its smaller amino acid sequence and toxicity, and its greater biological activity.


2020 ◽  
Vol 21 (4) ◽  
pp. 1478 ◽  
Author(s):  
Caroline Eozenou ◽  
Audrey Lesage-Padilla ◽  
Vincent Mauffré ◽  
Gareth D. Healey ◽  
Sylvaine Camous ◽  
...  

Forkhead Box L2 (FOXL2) is a member of the FOXL class of transcription factors, which are essential for ovarian differentiation and function. In the endometrium, FOXL2 is also thought to be important in cattle; however, it is not clear how its expression is regulated. The maternal recognition of pregnancy signal in cattle, interferon-Tau, does not regulate FOXL2 expression. Therefore, in the present study, we examined whether the ovarian steroid hormones that orchestrate implantation regulate FOXL2 gene expression in ruminants. In sheep, we confirmed that FOXL2 mRNA and protein was expressed in the endometrium across the oestrous cycle (day 4 to day 15 post-oestrus). Similar to the bovine endometrium, ovine FOXL2 endometrial expression was low during the luteal phase of the oestrous cycle (4 to 12 days post-oestrus) and at implantation (15 days post-oestrus) while mRNA and protein expression significantly increased during the luteolytic phase (day 15 post-oestrus in cycle). In pregnant ewes, inhibition of progesterone production by trilostane during the day 5 to 16 period prevented the rise in progesterone concentrations and led to a significant increase of FOXL2 expression in caruncles compared with the control group (1.4-fold, p < 0.05). Ovariectomized ewes or cows that were supplemented with exogenous progesterone for 12 days or 6 days, respectively, had lower endometrial FOXL2 expression compared with control ovariectomized females (sheep, mRNA, 1.8-fold; protein, 2.4-fold; cattle; mRNA, 2.2-fold; p < 0.05). Exogenous oestradiol treatments for 12 days in sheep or 2 days in cattle did not affect FOXL2 endometrial expression compared with control ovariectomized females, except at the protein level in both endometrial areas in the sheep. Moreover, treating bovine endometrial explants with exogenous progesterone for 48h reduced FOXL2 expression. Using in vitro assays with COS7 cells we also demonstrated that progesterone regulates the FOXL2 promoter activity through the progesterone receptor. Collectively, our findings imply that endometrial FOXL2 is, as a direct target of progesterone, involved in early pregnancy and implantation.


2017 ◽  
Vol 62 (2) ◽  
pp. 118 ◽  
Author(s):  
I. A. TSAKMAKIDIS (Ι.Α. ΤΣΑΚΜΑΚΙΔΗΣ) ◽  
T. KHALIFA ◽  
A. G. LYMBEROPOULOS (Α.Γ. ΛΥΜΠΕΡΟΠΟΥΛΟΣ) ◽  
I. A. MICHOS (Η.Α. ΜΙΧΟΣ) ◽  
C. M. BOSKOS (Κ.Μ. ΜΠΟΣΚΟΣ)

Chemicals such as heparin, calcium ionophore and dimethyl sulfoxide (DMSO) have been used in sperm's function evaluation assays, since they are facilitating the sperm capacitation and the induction of acrosome reaction. Many researchers modified porcine in vitro protocols purposing the improvement and validation of in vitro assays. The modification of the above mentioned chemicals' concentration could have a detrimental effect on sperm characteristics, relative to normal sperm function and fertilizing ability. The present study aimed to investigate in vitro effect of various concentrations of, a) heparin (2, 4, 6, 8 and 10 μg/ml), b) calcium ionophore A23187 (10, 20, 30 μΜ) and c) DMSO (1, 2, 3 % v/v), that have been used in sperm evaluation techniques, on chromatin instability and total motility of boar spermatozoa. Eight boars were used as semen donors, providing 20 ejaculates. Acridine orange test and subjective evaluation of semen by a microscope equipped with a heated plate were performed in order to evaluate chromatin integrity and motility, respectively. The results of this study showed that the addition of heparin, A23187 and DMSO at concentrations of 8 - 10 μ^πιΐ, 10 μΜ and 1%, respectively, can be used for in vitro handling of boar spermatozoa without reduction of their motility and chromatin quality.


2020 ◽  
Vol 13 (1) ◽  
pp. 045-053
Author(s):  
Gopinath Rana ◽  
Rajesh Juneja

Ashwagandha (Withania somnifera L. Dunal) is an important and traditional medicinal herb found in India. It has been reported that, Ashwagandha has potential anti-proliferative as well as chemo-accelerative activity. The goal of this study was to investigate the most probable reason behind Ashwagandha’s anti-proliferative and chemo-accelerative activity. In addition, chromatographically isolate and chemically characterize some new compound which have antineoplastic property and find the mode of action of it. In vitro assays (MTT and Western blot) for anti-tumorigenic potentiality of the isolated drug were carried out on HT-29, KB and HeLa cell lines. In this experimental study, purification and chemical characterization (by UV, FT-IR, HPLC, LC-MS, 1H-NMR) of an anti-cancer drug has been found as Paclitaxel. MTT-assay shows an average IC50 value of the isolated Paclitaxel is 10 nM. Western blot data reveals there may be ROS-associated p53-MDM2-related cell proliferation and apoptosis by the drug’s in vitro effect.


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