Functional and morphological changes of the thyroid gland following 5 days of pulsatile TRH stimulation in male rats

1995 ◽  
Vol 146 (2) ◽  
pp. 339-348 ◽  
Author(s):  
C Hoang-Vu ◽  
G Brabant ◽  
H Leitolf ◽  
A von zur Mühlen ◽  
H Dralle ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Morphological Changes ◽  
Dominant Role ◽  
Major Product ◽  
Male Rats ◽  
Ultrastructural Changes ◽  
Sprague Dawley ◽  
Immunogold Staining ◽  
Trh Stimulation

Abstract The aim of the present study was to evaluate in vivo the selective effects of a small increase in plasma TSH levels on thyroid function, proliferation and morphology. Chronically catheterized male Sprague–Dawley rats were stimulated i.v. over 5 days either with TRH (2 μg TRH in 100 μl 0·9% (w/v) NaCl (TRH-P) or the NaCl carrier alone (P), both given as pulses every 2 h. Control groups were cotreated i.v. with 10 μg thyroxine (T4)/100 g body weight per day (TRH-P+T4) starting 2 days before pulsatile stimulation. TSH plasma levels were approximately doubled by TRH-P (P≤0·001), T4 plasma levels significantly increased (P≤0·001) but tri-iodothyronine plasma levels did not change compared with treatment with P. No significant changes between groups were found in thyroid weight and in intrathyroidal iodine content, but the percentage of 5-bromo-2′-desoxyuridinelabelled thyrocytes as a marker of proliferation in TRH-P-treated animals was significantly increased over P or TRH-P+T4 (P≤0·001). Ultrastructural analysis of the thyroid evaluated by electron microscopy revealed a significant increase in the number of lysosomes (P≤0·001). The size of the endoplasmic reticulum (ER) in relation to the cytoplasm was significantly increased when treated with TRH-P compared with P or TRH-P+T4 (P≤0·001). Post-embedding immunogold staining revealed Tg as a major product within ER cisternae. Immunogold labelling was moderate in controls and higher densities of gold particles were obtained in TRH-P-treated animals (P≤0·001). In conclusion, short-term pulsatile TRH stimulation increasing the plasma levels of immunoreactive TSH only twofold is capable of inducing hypertrophy of the thyrocytes by gross ultrastructural changes which are paralleled by an increase in circulating T4. These data underscore the dominant role of TSH on thyroid ultrastructure within the narrow boundaries of normal physiological regulation. Journal of Endocrinology (1995) 146, 339–348

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 Bone Regeneration Capacity of Newly Developed Uncalcined/Unsintered Hydroxyapatite and Poly-l-lactide-co-glycolide Sheet in Maxillofacial Surgery: An In Vivo Study

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Huy Xuan Ngo ◽  
Quang Ngoc Dong ◽  
Yunpeng Bai ◽  
Jingjing Sha ◽  
Shinji Ishizuka ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Reconstructive Surgery ◽  
Early Stage ◽  
Maxillofacial Surgery ◽  
Male Rats ◽  
Regeneration Ability ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Rat Mandible

Uncalcined/unsintered hydroxyapatite and poly-l-lactide-co-glycolide (u-HA/PLLA/PGA) is a new bioresorbable nanomaterial with superior characteristics compared with current bioresorbable materials, including appropriate mechanical properties, outstanding bioactive/osteoconductive features, and remarkably shorter resorption time. Nevertheless, the bone regeneration characteristics of this nanomaterial have not been evaluated in maxillofacial reconstructive surgery. In this study, we used a rat mandible model to assess the bone regeneration ability of u-HA/PLLA/PGA material, compared with uncalcined/unsintered hydroxyapatite and poly-l-lactide acid (u-HA/PLLA) material, which has demonstrated excellent bone regenerative ability. A 4-mm-diameter defect was created at the mandibular angle area in 28 Sprague Dawley male rats. The rats were divided into three groups: u-HA/PLLA/PGA (u-HA/PLLA/PGA graft + defect), u-HA/PLLA (u-HA/PLLA graft + defect), and sham control (defect alone). At 1, 3, 8, and 16 weeks after surgeries, the rats were sacrificed and assessed by micro-computed tomography, histological analysis with hematoxylin and eosin staining, and immunohistochemical analyses. The results confirmed that the accelerated bone bioactive/regenerative osteoconduction of u-HA/PLLA/PGA was comparable with that of u-HA/PLLA in the rat mandible model. Furthermore, this new regenerative nanomaterial was able to more rapidly induce bone formation in the early stage and had great potential for further clinical applications in maxillofacial reconstructive surgery.

scholarly journals Bone Regeneration Potential of Uncalcined and Unsintered Hydroxyapatite/Poly l-lactide Bioactive/Osteoconductive Sheet Used for Maxillofacial Reconstructive Surgery: An In Vivo Study

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2931 ◽  
Author(s):  
Quang Ngoc Dong ◽  
Takahiro Kanno ◽  
Yunpeng Bai ◽  
Jingjing Sha ◽  
Katsumi Hideshima
Keyword(s):  
Bone Regeneration ◽  
Maxillofacial Surgery ◽  
Male Rats ◽  
Regeneration Ability ◽  
Sprague Dawley ◽  
Control Groups ◽  
Critical Size Defect ◽  
Hematoxylin And Eosin ◽  
Regenerative Ability

Uncalcined and unsintered hydroxyapatite/poly l-lactide (u-HA/PLLA) material has osteoconductive characteristics and is available for use as a maxillofacial osteosynthetic reconstruction device. However, its bone regeneration ability in the maxillofacial region has not been fully investigated. This study is the first to assess the bone regenerative potential of osteoconductive u-HA/PLLA material when it is used for repairing maxillofacial bone defects. A total of 21 Sprague-Dawley male rats were divided into three groups—the u-HA/PLLA, PLLA, or sham control groups. A critical size defect of 4 mm was created in the mandible of each rat. Then, the defect was covered with either a u-HA/PLLA or PLLA sheet on the buccal side. The rats in each group were sacrificed at 2, 4, or 8 weeks. The rats’ mandibles were sampled for histological analysis with hematoxylin and eosin staining, histomorphometry, and immunohistochemistry with Runx2 and osteocalcin (OCN) antibody. The amount of newly formed bone in the u-HA/PLLA group was significantly higher than that of the PLLA group. The expression of Runx2 and OCN in the u-HA/PLLA group was also significantly higher. These results demonstrate that the u-HA/PLLA material has excellent bone regenerative ability and confirm its applicability as a reconstructive device in maxillofacial surgery.

scholarly journals Metabolic and cardiac signaling effects of inhaled hydrogen sulfide and low oxygen in male rats

2012 ◽  
Vol 112 (10) ◽  
pp. 1659-1669 ◽  
Author(s):  
Asaf Stein ◽  
Zhengkuan Mao ◽  
Joanna P. Morrison ◽  
Michelle V. Fanucchi ◽  
Edward M. Postlethwait ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Tissue Injury ◽  
Biological Effects ◽  
Male Rats ◽  
Sprague Dawley ◽  
Low Oxygen ◽  
Creatine Kinase Mb ◽  
Gsk 3Β

Low concentrations of inhaled hydrogen sulfide (H2S) induce hypometabolism in mice. Biological effects of H2S in in vitro systems are augmented by lowering O2 tension. Based on this, we hypothesized that reduced O2 tension would increase H2S-mediated hypometabolism in vivo. To test this, male Sprague-Dawley rats were exposed to 80 ppm H2S at 21% O2 or 10.5% O2 for 6 h followed by 1 h recovery at room air. Rats exposed to H2S in 10.5% O2 had significantly decreased body temperature and respiration compared with preexposure levels. Heart rate was decreased by H2S administered under both O2 levels and did not return to preexposure levels after 1 h recovery. Inhaled H2S caused epithelial exfoliation in the lungs and increased plasma creatine kinase-MB activity. The effect of inhaled H2S on prosurvival signaling was also measured in heart and liver. H2S in 21% O2 increased Akt-PSer473 and GSK-3β-PSer9 in the heart whereas phosphorylation was decreased by H2S in 10.5% O2, indicating O2 dependence in regulating cardiac signaling pathways. Inhaled H2S and low O2 had no effect on liver Akt. In summary, we found that lower O2 was needed for H2S-dependent hypometabolism in rats compared with previous findings in mice. This highlights the possibility of species differences in physiological responses to H2S. Inhaled H2S exposure also caused tissue injury to the lung and heart, which raises concerns about the therapeutic safety of inhaled H2S. In conclusion, these findings demonstrate the importance of O2 in influencing physiological and signaling effects of H2S in mammalian systems.

Contribution of whole blood to the control of plasma asymmetrical dimethylarginine

2006 ◽  
Vol 291 (4) ◽  
pp. H1788-H1796 ◽  
Author(s):  
Scott S. Billecke ◽  
Laura A. Kitzmiller ◽  
Joseph J. Northrup ◽  
Steven E. Whitesall ◽  
Masumi Kimoto ◽  
...  
Keyword(s):  
Whole Blood ◽  
Ex Vivo ◽  
Dominant Role ◽  
Peptide Bond ◽  
Sprague Dawley ◽  
Asymmetrical Dimethylarginine ◽  
Sprague Dawley Rats ◽  
Endogenous Nitric Oxide ◽  
Nos Inhibitor

The endogenous nitric oxide (NO) synthase (NOS) inhibitor asymmetrical dimethylarginine (ADMA) is elevated in many patients and may contribute to the initiation and progression of their disease. While some mechanistic pathways have been identified, tissue-specific contributions to ADMA control remain unclear. We sought to determine if whole blood (WB) could participate in ADMA control ex vivo. Anesthetized male Sprague-Dawley rats underwent exsanguinations, and WB preparations were incubated at 37°C for 5 h. ADMA and symmetrical dimethylarginine were analyzed by high-pressure liquid chromatography. Incubation of lysed red blood cell (RBC) supernatant yielded a significant decrease in ADMA that was blocked by 4124W, a synthetic inhibitor of dimethylarginine dimethylaminohydrolase, the only reported enzyme to hydrolyze ADMA. Hydrolysis of ADMA was diminished by addition of physiologically relevant concentrations of zinc (i.e., 20 μM). Conversely, when rat WB or WB supernatant was incubated at 37°C, it liberated quantities of free ADMA (1–2 μM) that in vivo would likely have pathological consequences. Addition of arginine methyltransferase inhibitors to these incubations did not reduce ADMA release, indicating no dominant role for active protein methylation during these incubations. This ADMA liberation was significantly reduced by addition of protease inhibitors, indicating a dependence on peptide bond hydrolysis. Total ADMA (protein incorporated plus free) was determined by acid hydrolysis and found to be 43.18 ± 4.79 μM in WB with ∼95% of this in RBCs. These ex vivo data demonstrate the potential of blood to control the NO-NOS system by modulating free ADMA.

scholarly journals Oestradiol decreases rat apolipoprotein AI transcription via promoter site B

2000 ◽  
Vol 25 (2) ◽  
pp. 207-219 ◽  
Author(s):  
AH Taylor ◽  
AE Fox-Robichaud ◽  
C Egan ◽  
J Dionne ◽  
DE Lawless ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Target Genes ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Sprague Dawley ◽  
Male Adult ◽  
Nuclear Extracts ◽  
Major Mode ◽  
Apo Ai

Oestrogens protect against ischaemic heart disease in the post-menopausal female by increasing serum concentrations of apolipoprotein (apo) AI and the abundance of high-density lipoprotein particles. In men and experimental male animals, the administration of oestrogen has variable effects on apo AI expression. As the major mode of oestrogen action on target genes involves regulating promoter activity and hence transcription, oestrogen is expected to alter transcription of the apo AI gene. To test this hypothesis, the effect of 17beta-oestradiol (E(2)), on rat apo AI promoter activity in male hepatoma HuH-7 cells, was tested by co-transfecting a reporter template, pAI.474.CAT containing-474 to-7 of the rat apo AI promoter and an oestrogen receptor (ER) expression vector, pCMV-ER. Transfected cells exposed to E(2) showed a dose-dependent decrease in chloramphenicol acetyltransferase (CAT)-activity, with a maximum 91+/-1.5% reduction at 1 microM E(2). Deletional analysis of the promoter localized the inhibitory effect of ER and E(2) to site B (-170 to-144) with an adjacent 5' contiguous motif, site S (-186 to-171) acting as an amplifier. HuH-7 cell nuclear extracts showed binding activities with both sites S and B, but recombinant human ER did not. Furthermore, nuclear extracts from E(2)-treated HuH-7 cells showed weaker binding activity to site B, but not to site S. In summary, the inhibitory effect of ER and E(2) on rat apo AI gene activity is mediated by a promoter element, site B. This inhibitory effect arises from a mechanism that does not involve direct ER binding to the B-element. The conclusion that E(2) inhibits apo AI transcription was confirmed in vivo. Treatment of male adult Sprague-Dawley rats with up to 200 microg E(2) for 7 days decreased apo AI protein and hepatic mRNA by 72+/-21% and 68+/-1.4% respectively. Results of 'run-on' transcription of the apo AI gene in isolated hepatic nuclei showed a 55% decrease in hormone-treated male rats. These findings suggest that E(2) exerts primarily an inhibitory effect within male hepatic nuclei.

scholarly journals Myrmecodia platytyrea Methanol Tuber Extract Ameliorates Hyperglycemia In STZ-Induced Diabetic Sprague-Dawley Male Rats

2021 ◽  
pp. 338-348
Author(s):  
Mizaton Hazizul Hasan ◽  
Hasbullani Zakaria ◽  
Ibtisam Abdul Wahab ◽  
Thellie Ponto ◽  
Aishah Adam
Keyword(s):  
Blood Glucose ◽  
Fasting Blood Glucose ◽  
Density Lipoprotein ◽  
Diabetic Rats ◽  
Male Rats ◽  
Current Therapy ◽  
Diabetic Patients ◽  
Sprague Dawley ◽  
Tuber Extract

Type 2 diabetes mellitus (T2DM) is one of the main non-communicable chronic diseases that has many complications that compromise the quality of life. Hence, the need to find alternatives to replace the current therapy or as an adjuvant. Tubers of Myrmecodia platytytrea (Rubiaceae) has been used traditionally as an alternative therapy for the management of cancer and other inflammatory-related disorders. The aim of this study was to investigate the potency of M. platytytrea methanolic tuber extract (MPMTE) as an antihyperglycemic agent, in vivo. :The streptozotocin (STZ)-induced diabetic rats were treated orally with MPMTE (100, 200 and 400 mg/kg) and metformin (positive control, 100 mg/kg) daily for 14 days. Blood glucose level and other biochemistry analysis were conducted including histological examination on liver, kidney and pancreas.  The STZ-induced diabetic rats treated with MPMTE (200 and 400 mg/kg) had significant decreased (p<0.05) in fasting blood glucose, total cholesterol, triglycerides and low-density lipoprotein (LDL) with no significant changes in high-density lipoprotein (HDL) compared to STZ-induced untreated diabetic rats. Liver, kidney and pancreas were devoid of any damage caused by STZ.  MPMTE had strong antihyperglycaemic activity and was protective against any STZ-induced organ damage. Thus, MPMTE can be further developed into an adjuvant therapy for diabetic patients.

scholarly journals Trimethyl Chitosan Hydrogel Nanoparticles for Progesterone Delivery in Neurodegenerative Disorders

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 657 ◽  
Author(s):  
Maria Cristina Cardia ◽  
Anna Rosa Carta ◽  
Pierluigi Caboni ◽  
Anna Maria Maccioni ◽  
Sara Erbì ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Sodium Tripolyphosphate ◽  
Fold Increase ◽  
Male Rats ◽  
In Vivo Studies ◽  
Sprague Dawley ◽  
Neuroprotective Effects ◽  
Trimethyl Chitosan ◽  
Hydrogel Nanoparticles

Progesterone is a sex hormone which shows neuroprotective effects in different neurodegenerative disorders, including Parkinson’s disease, stroke, and Alzheimer’s disease. However, the pharmacokinetic limitations associated with the peripheral administration of this molecule highlight the need for more efficient delivery approaches to increase brain progesterone levels. Since the nose-to-brain administration of mucoadhesive hydrogel nanoparticles is a non-invasive and convenient strategy for the delivery of therapeutics to the central nervous system, in this work, progesterone-loaded hydrogel nanoparticle formulations have been prepared, characterized, and tested in vivo. Nanoparticles, loaded with different progesterone concentrations, have been obtained by polyelectrolyte complex formation between trimethyl chitosan and sodium alginate, followed by ionotropic gelation with sodium tripolyphosphate as a cross-linking agent. All formulations showed a mean diameter ranging from 200 nm to 236 nm, a polydispersity index smaller than 0.23, and a high progesterone encapsulation efficiency (83–95%). The zeta potential values were all positive and greater than 28 mV, thus ensuring nanoparticles stability against aggregation phenomena as well as interaction with negative sialic residues of the nasal mucosa. Finally, in vivo studies on Sprague–Dawley male rats demonstrated a 5-fold increase in brain progesterone concentrations compared to basal progesterone level after 30 min of hydrogel nanoparticle inhalation.

scholarly journals Osseointegration of Alkali-Modified NANOZR Implants: An In Vivo Study

2019 ◽  
Vol 20 (4) ◽  
pp. 842 ◽  
Author(s):  
Satoshi Komasa ◽  
Mariko Nishizaki ◽  
Honghao Zhang ◽  
Seiji Takao ◽  
Derong Yin ◽  
...  
Keyword(s):  
Bending Strength ◽  
Bone Marrow Cells ◽  
Alkali Treatment ◽  
Treated Group ◽  
Fluorescent Labeling ◽  
Male Rats ◽  
Sprague Dawley ◽  
Bone Differentiation

Ingredients and surface modification methods are being continually developed to improve osseointegration of dental implants and reduce healing times. In this study, we demonstrate in vitro that, by applying concentrated alkali treatment to NANOZR with strong bending strength and fracture toughness, a significant improvement in the bone differentiation of rat bone marrow cells can be achieved. We investigated the influence of materials modified with this treatment in vivo, on implanted surrounding tissues using polychrome sequential fluorescent labeling and micro-computer tomography scanning. NANOZR implant screws in the alkali-treated group and the untreated group were evaluated after implantation in the femur of Sprague–Dawley male rats, indicating that the amount of new bone in the alkali-modified NANOZR was higher than that of unmodified NANOZR. Alkali-modified NANOZR implants proved to be useful for the creation of new implant materials.

scholarly journals Ghrelin Ameliorates Angiotensin II-Induced Myocardial Fibrosis by Upregulating Peroxisome Proliferator-Activated Receptor Gamma in Young Male Rats

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Qian Wang ◽  
Xin Sui ◽  
Rui Chen ◽  
Pei-Yong Ma ◽  
Yong-Liang Teng ◽  
...  
Keyword(s):  
Myocardial Fibrosis ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Male Rats ◽  
Peroxisome Proliferator ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Collagen Iii

Angiotensin (Ang) II contributes to the formation and development of myocardial fibrosis. Ghrelin, a gut peptide, has demonstrated beneficial effects against cardiovascular disease. In the present study, we explored the effect and related mechanism of Ghrelin on myocardial fibrosis in Ang II-infused rats. Adult Sprague-Dawley (SD) rats were divided into 6 groups: Control, Ang II (200ng/kg/min, microinfusion), Ang II+Ghrelin (100μg/kg, subcutaneously twice daily), Ang II+Ghrelin+GW9662 (a specific PPAR-γinhibitor, 1 mg/kg/d, orally), Ang II+GW9662, and Ghrelin for 4 wks. In vitro, adult rat cardiac fibroblasts (CFs) were pretreated with or without Ghrelin, Ghrelin+GW9662, or anti-Transforming growth factor (TGF)-β1 antibody and then stimulated with or without Ang II (100 nmol/L) for 24 h. Ang II infusion significantly increased myocardial fibrosis, expression of collagen I, collagen III, and TGF-β1, as well as TGF-β1 downstream proteins p-Smad2, p-Smad3, TRAF6, and p-TAK1 (all p<0.05). Ghrelin attenuated these effects. Similar results were seen in Ang II-stimulated rat cardiac fibroblasts in vitro. In addition, Ghrelin upregulated PPAR-γexpressionin vivoandin vitro, and treatment with GW9662 counteracted the effects of Ghrelin. In conclusion, Ghrelin ameliorated Ang II-induced myocardial fibrosis by upregulating PPAR-γand in turn inhibiting TGF-β1signaling.

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