scholarly journals 5-Hydroxytryptamine (5HT) Receptors in the Heart Valves of Cynomolgus Monkeys and Sprague-Dawley Rats

2005 ◽  
Vol 53 (5) ◽  
pp. 671-677 ◽  
Author(s):  
Chandikumar S. Elangbam ◽  
Ruth M. Lightfoot ◽  
Lawrence W. Yoon ◽  
Donald R. Creech ◽  
Robert S. Geske ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Heart Valves ◽  
Cell Types ◽  
Positive Staining ◽  
Normal Heart ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Positive Immunostaining ◽  
5Ht2c Receptor ◽  
Polymerase Chain

5-Hydroxytryptamine-2B receptor (5HT2BR) stimulation is known to cause fibroblast mitogenesis, and the mitogenic effect has been proposed to trigger valvular heart disease in humans. In this study, we used real-time polymerase chain reaction (TaqMan) to quantify transcript levels of 5HT2B, 5HT2C, and 5HT1B receptors and immunohistochemistry (IHC) to detect the tissue localization of these receptors in the normal heart valves of cynomolgus (CM) monkeys and Sprague-Dawley (S-D) rats. In both species, positive immunostaining was noted for 5HT1B and 5HT2B receptors in mitral, tricuspid, aortic, and pulmonary valves, and the cell types showing positive staining were interstitial cells and endothelial cells lining the valve leaflet. In CM monkeys, 5HT2CR was expressed only in the endothelial cells lining the leaflet, whereas S-D valves were negative for this receptor. IHC results were correlated with 5HT2B and 5HT1B receptor transcripts for all four valves. However, 5HT2C receptor transcripts were lower than 5HT2B or 5HT1B in all CM monkey valves, whereas 5HT2C transcripts were below the level of detection in any of the S-D rat valves. Our data showed the expression of 5HT2B, 5HT1B, and 5HT2C receptors in the normal heart valves of CM monkeys and S-D rats, and IHC and TaqMan techniques may be used to study the potential mechanism of compounds with 5HT2BR agonist activity.

Abstract 637: Hydrogen Sulfide Acts on Endothelial Cells to Elicit Dilation.

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Nancy L Kanagy ◽  
Jessica M Osmond ◽  
Olan Jackson-Weaver ◽  
Benjimen R Walker
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Hydrogen Sulfide ◽  
Mesenteric Arteries ◽  
Direct Effects ◽  
Sprague Dawley ◽  
Imaging Studies ◽  
Knock Out ◽  
Event Frequency ◽  
Sprague Dawley Rats

Hydrogen sulfide (H 2 S), produced by the enzyme cystathionine-γ lyase (CSE), dilates arteries by hyperpolarizing and relaxing vascular smooth muscle cells (VSMC) and CSE knock-out causes hypertension and endothelial dysfunction showing the importance of this system. However, it is not clear if H 2 S-induced VSMC depolarization and relaxation is mediated by direct effects on VSMC or indirectly through actions on endothelial cells (EC). We reported previously that disrupting EC prevents H 2 S-induced vasodilation suggesting H 2 S might act directly on EC. Because inhibiting large-conductance Ca 2+ -activated K + (BK Ca ) channels also inhibits H 2 S-induced dilation, we hypothesized that H 2 S activates EC BK Ca channels to hyperpolarize EC and increase EC Ca 2+ which stimulates release of a secondary hyperpolarizing factor. Small mesenteric arteries from male Sprague-Dawley rats were used for all experiments. We found that EC disruption prevented H 2 S-induced VSMC membrane potential ( E m ) hyperpolarization. Blocking EC BK Ca channels with luminal application of the BK Ca inhibitor, iberiotoxin (IbTx, 100 nM), also prevented NaHS-induced dilation and VSMC hyperpolarization but did not affect resting VSMC E m showing EC specific actions. Sharp electrode recordings in arteries cut open to expose EC demonstrated H 2 S-induced hyperpolarization of EC while Ca 2+ imaging studies in fluor-4 loaded EC showed that H 2 S increases EC Ca 2+ event frequency. Thus H 2 S can act directly on EC. Inhibiting the EC enzyme cytochrome P 450 2C (Cyp2C) with sulfaphenazole also prevented VSMC depolarization and vasodilation. Finally, inhibiting TRPV4 channels to block the target of the Cyp2C product 11,12-EET inhibited NaHS-induced dilation. Combined with our previous report that CSE inhibition decreases BK Ca currents in EC, these results suggest that H 2 S stimulates EC BK Ca channels and activates Cyp2C upstream of VSMC hyperpolarization and vasodilation.

The cartilage degeneration in a growing rat experimental model of developmental trochlear dysplasia is associated with activation of PI3K/AKT signal pathway

2020 ◽  
Author(s):  
Wei Lin ◽  
Yike Dai ◽  
Jinghui Niu ◽  
Chongyi Fan ◽  
Xunkai Feng ◽  
...  
Keyword(s):  
Trochlear Dysplasia ◽  
Cartilage Degeneration ◽  
Signal Pathway ◽  
Control Group ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Growing Rat ◽  
Polymerase Chain ◽  
Underlying Mechanisms ◽  
Experimental Group

Abstract Background As one of the lower extremity deformities in human, trochlear dysplasia is a commonly encountered disease. However, the molecular mechanism of cartilage degeneration in trochlear dysplasia is indefinite yet. It was apparent to all that PI3K/AKT signal pathway is extremely significant in regulating the pathophysiological process of cartilage degeneration. The purpose of this research is to discuss the correlation between PI3K/AKT signal pathway and trochlear dysplasia cartilage degeneration. Materials and methods 120 female Sprague-Dawley rats at 4 weeks of age were separate into control group and experimental group randomly. The distal femurs were isolated from the experimental and unsurgeried control group at the point of the 4, 8, 12 weeks, correspondingly. Micro-CT and histological examination were carried out to investigate the anatomical structure and cartilage changes of the trochlear. Subsequently, the expression of PI3K/AKT, TGFβ1 and ADAMTS-4 in cartilage were investigated by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). Results In the experimental group, the trochlear dysplasia model was successfully established at 8 weeks after surgery. Moreover, the cartilage degeneration was found from 8 weeks, with continued higher protein and mRNA expression of PI3K/AKT, TGFβ1 and ADAMTS-4 compared with the control group. Conclusions This research suggested that patellar instability may lead to trochlear dysplasia in growing rats. Moreover, trochlear dysplasia was probably one of the causes of patellofemoral osteoarthritis and the cartilage degeneration in trochlear dysplasia might be associate with activation of PI3K/AKT signal pathway. However, more research was required to clarify the underlying mechanisms.

Regression of white adipose tissue in diabetic rats

1989 ◽  
Vol 257 (4) ◽  
pp. E547-E553 ◽  
Author(s):  
A. Geloen ◽  
P. E. Roy ◽  
L. J. Bukowiecki
Keyword(s):  
Endothelial Cells ◽  
Adipose Tissue ◽  
Protein Content ◽  
Cell Number ◽  
Diabetic Rats ◽  
Total Protein Content ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Wet Weight

The effects of long-term diabetes (4 wk) on the development of parametrial (PWAT) and retroperitoneal (RWAT) white adipose tissues were studied in young Sprague-Dawley rats (170-200 g) injected with a single dose of streptozotocin (75 mg/kg). Diabetes stopped animal growth and totally abolished the normal increases in the wet weight, total protein content, and cellularity (estimated by DNA content) of PWAT and RWAT. Remarkably, the prolonged lack of insulin induced a progressive decrease of the cellularity of RWAT to levels that were lower than those of the initial controls. It also resulted in a marked reduction of adipocyte size. The tiny adipocytes seen in diabetic animals were characterized by the presence of multilocular triglyceride droplets. In general, the decreases in cell number, cell size, and protein content were more pronounced in RWAT than in PWAT. Quantitative cellular frequency studies revealed that adipocytes, and possibly also endothelial cells, contribute to the decrease in RWAT cellularity. The results demonstrate that 1) diabetes inhibits proliferative activity in adipose tissue, 2) total cell number reduction may occur in adipose depot of young growing rats, 3) this effect is depot dependent, and 4) the turnover of adipocytes and endothelial cells is relatively slow (several weeks).

Hydrogen Peroxide and Lipopolysaccharide Differentially Affect the Expression of MicroRNAs 10a, 33a, 21, 221 in Endothelial Cells Before and After Coculture With Monocytes

2017 ◽  
Vol 36 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Atefe Ghamar Talepoor ◽  
Mehdi Kalani ◽  
Alamtaj Samsami Dahaghani ◽  
Mehrnoosh Doroudchi
Keyword(s):  
Endothelial Cells ◽  
Mononuclear Cells ◽  
Cell Types ◽  
Magnetic Bead ◽  
Complete Medium ◽  
Peripheral Blood Mononuclear ◽  
Factors Affecting ◽  
Before And After ◽  
Polymerase Chain ◽  
Cellular Stressors

Inflammation and oxidative stress are important risk factors affecting various cells in the formation of atherosclerosis. MicroRNAs (miRs) are regulators of inflammation and atherogenesis. The expressions of endothelial cell (EC)-specific miR-10a and miR-21 and monocyte-specific miR-33a and miR-221 were investigated using coculture of the ECs and monocytes upon exposure to H2O2 as an oxidative stressor, and endotoxin/lipopolysaccharide (LPS) as a microbial stressor. Human umbilical endothelial cells (HUVECs) and peripheral blood mononuclear cells (or monocytes) were cocultured in M199 complete medium and were incubated with LPS (20 ng/mL) or H2O2 (1%) for 8 hours at 37°C. The HUVECs and monocytes were then separated from the cellular mix using a magnetic bead negative selection technique. The relative expression of miRs was determined by real-time polymerase chain reaction. In both cell types, H2O2 induced miR10a ( P = 0.05) and LPS induced miR21 ( P = 0.0003) compared to the untreated controls. Coculture increased miR-10a and miR-21 expression in monocytes ( P = 0.0008 and <0.0001); however when cultured alone, HUVECs expressed higher levels of miR-10a and miR-21 ( P < 0.0001 and <0.0001). Coculture decreased the expression of miR-33a in monocytes ( P < 0.0001) while increasing miR221 in HUVECs and monocytes ( P < 0.0001 and <0.0001). The expression pattern of miRs in HUVECs and monocytes changes in the coculture compared to culturing alone in response to oxidative and microbial toxic compounds. Moreover, different cellular stressors induce different athero-miRs, which may affect the course of inflammation.

scholarly journals Molecular and functional characteristics of heart-valve interstitial cells

2007 ◽  
Vol 362 (1484) ◽  
pp. 1437-1443 ◽  
Author(s):  
Adrian H Chester ◽  
Patricia M Taylor
Keyword(s):  
Endothelial Cells ◽  
Heart Valve ◽  
Heart Valves ◽  
Cell Types ◽  
Interstitial Cells ◽  
Individual Characteristics ◽  
The Body ◽  
Integral Role ◽  
Valve Function ◽  
And Function

The cells that reside within valve cusps play an integral role in the durability and function of heart valves. There are principally two types of cells found in cusp tissue: the endothelial cells that cover the surface of the cusps and the interstitial cells (ICs) that form a network within the extracellular matrix (ECM) within the body of the cusp. Both cell types exhibit unique functions that are unlike those of other endothelial and ICs found throughout the body. The valve ICs express a complex pattern of cell-surface, cytoskeletal and muscle proteins. They are able to bind to, and communicate with, each other and the ECM. The endothelial cells on the outflow and inflow surfaces of the valve differ from one another. Their individual characteristics and functions reflect the fact that they are exposed to separate patterns of flow and pressure. In addition to providing a structural role in the valve, it is now known that the biological function of valve cells is important in maintaining the integrity of the cusps and the optimum function of the valve. In response to inappropriate stimuli, valve interstitial and endothelial cells may also participate in processes that lead to valve degeneration and calcification. Understanding the complex biology of valve interstitial and endothelial cells is an important requirement in elucidating the mechanisms that regulate valve function in health and disease, as well as setting a benchmark for the function of cells that may be used to tissue engineer a heart valve.

scholarly journals Experimental Study of the Effects of Hypoxia Simulator on Osteointegration of Titanium Prosthesis in Osteoporotic Rats

2021 ◽  
Author(s):  
Jiangfeng Liu ◽  
Huijun Kang ◽  
Jiangfeng Lu ◽  
Yike Dai ◽  
Fei Wang
Keyword(s):  
Control Group ◽  
Osteoporotic Bone ◽  
Mrna Levels ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Pull Out ◽  
Sprague Dawley Rats ◽  
Bone To Implant Contact ◽  
Polymerase Chain ◽  
And Control

Abstract Purpose: Poor osseointegration is the key reason for implant failure after arthroplasty, whether in osteoporotic or normal bone conditions. To date, osseointegration remains a major challenge. Recent studies have shown that deferoxamine(DFO) can accelerate osteogenesis by activation of the hypoxia signal pathway. The purpose of this study is to test the following hypothesis: after knee replacement, intra-articular injection of DFO will promote osteogenesis and osseointegration with titanium prosthesis in the bones of osteoporotic rats.Materials and Methods: 90 female sprague-dawley rats were used for the experiment. Ovariectomy and knee arthroplasty were performed. Then, the rats were randomly divided into DFO and control group(n=40 per group). The two groups were treated by intraarticular injection of DFO and saline respectively. After 2 weeks, polymerase chain reaction(PCR) and immunohistochemistry were used to evaluate the levels of HIF-1a, VEGF and CD31. After 12 weeks, the specimens were examined by micro CT, biomechanics and histopathology to evaluate osteogenesis and osseointegration.Results: The results of PCR showed mRNA levels of VEGF and CD31 in DFO group were significantly higher than those in control group. The immunohistochemistry results indicated positive cell expressions of HIF-1a, VEGF and CD31 in DFO group were also higher. Compared to control group, the microCT parameters of BMD, BV/TV, TB.N, TB.Th were significantly higher. The maximal pull-out force and the bone-to-implant contact (BIC) value were also higher . Conclusions: The local administration of DFO which is used to activate HIF-1a signaling pathway can promote osteogenesis and osseointegration with the prosthesis in osteoporotic bone.

A high-sucrose diet increases gluconeogenic capacity in isolated periportal and perivenous rat hepatocytes

2001 ◽  
Vol 280 (5) ◽  
pp. E695-E702 ◽  
Author(s):  
Michael E. Bizeau ◽  
Jeffrey S. Thresher ◽  
Michael J. Pagliassotti
Keyword(s):  
Rat Hepatocytes ◽  
Cell Types ◽  
Cell Populations ◽  
Sprague Dawley ◽  
Glucose Release ◽  
Sprague Dawley Rats ◽  
Pv Cell ◽  
High Sucrose Diet ◽  
Gluconeogenic Substrates ◽  
High Sucrose

A high-sucrose (SU) diet increases gluconeogenesis (GNG) in the liver. The present study was conducted to determine the contribution of periportal (PP) and perivenous (PV) cell populations to this SU-induced increase in GNG. Male Sprague-Dawley rats were fed an SU (68% sucrose) or starch (ST, 68% starch) diet for 1 wk, and hepatocytes were isolated from the PP or PV region of the liver acinus. Hepatocytes were incubated for 1 h in the presence of various gluconeogenic substrates, and glucose release into the medium was used to estimate GNG. When incubated in the presence of 5 mM lactate, which enters GNG at the level of pyruvate, glucose release (nmol · h−1 · mg−1) was significantly increased by the SU diet in both PP (84.8 ± 3.4 vs. 70.4 ± 2.6) and PV (64.3 ± 2.5 vs. 38.2 ± 2.1) cells. Addition of palmitate (0.5 mM) increased glucose release from lactate in PP cells by 11.6 ± 0.5 and 20.6 ± 1.5% and in PV cells by 11.0 ± 4.4 and 51.1 ± 9.1% in SU and ST, respectively. When cells were incubated with 5 mM dihydroxyacetone (DHA), which enters GNG at the triosephosphate level, glucose release was significantly increased by the SU diet in both cell types. In contrast, glucose release from fructose (0.5 mM) was significantly increased by the SU diet in PV cells only. These changes in glucose release were accompanied by significant increases in the maximal specific activities of glucose-6-phosphatase (G-6-Pase) and phospho enolpyruvate carboxykinase (PEPCK) in both PP and PV cells. These data suggest that the SU diet influences GNG in both PP and PV cell populations. It appears that SU feeding produces changes in GNG via alterations in at least two critical enzymes, G-6-Pase and PEPCK.

scholarly journals Manganese exposure induces permeability in renal glomerular endothelial cells via the Smad2/3-Snail–VE-cadherin axis

2020 ◽  
Vol 9 (5) ◽  
pp. 683-692
Author(s):  
Peng Gao ◽  
Yutian Tian ◽  
Qi Xie ◽  
Liang Zhang ◽  
Yongjian Yan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Zinc Finger Protein ◽  
Vascular Endothelial ◽  
Sprague Dawley ◽  
Glomerular Diseases ◽  
Cell Monolayers ◽  
Vascular Endothelial Cadherin ◽  
Glomerular Endothelial Cells ◽  
Sprague Dawley Rats ◽  
Glomerular Endothelium

Abstract Manganese (Mn) is an essential micronutrient. However, it is well established that Mn overexposure causes nervous system diseases. In contrast, there are few reports on the effects of Mn exposure on glomerular endothelium. In the present study, the potential effects of Mn exposure on glomerular endothelium were evaluated. Sprague Dawley rats were used as a model of Mn overexposure by intraperitoneal injection of MnCl2·H2O at 25 mg/kg body weight. Mn exposure decreased expression of vascular endothelial-cadherin, a key component of adherens junctions, and increased exudate from glomeruli in Sprague Dawley rats. Human renal glomerular endothelial cells were cultured with different concentration of Mn. Exposure to 0.2 mM Mn increased permeability of human renal glomerular endothelial cell monolayers and decreased vascular endothelial-cadherin expression without inducing cytotoxicity. In addition, Mn exposure increased phosphorylation of mothers against decapentaplegic homolog 2/3 and upregulated expression of zinc finger protein SNAI1, a negative transcriptional regulator of vascular endothelial-cadherin. Our data suggest Mn exposure may contribute to development of glomerular diseases by inducing permeability of glomerular endothelium.

scholarly journals Changes in Gastric Smooth Muscle Cell Contraction during Pregnancy: Effect of Estrogen

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Othman A. Al-Shboul ◽  
Hanan J. Al-Rshoud ◽  
Ahmed N. Al-Dwairi ◽  
Mohammad A. Alqudah ◽  
Mahmoud A. Alfaqih ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Late Pregnancy ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sprague Dawley ◽  
Gastric Smooth Muscle ◽  
Sprague Dawley Rats ◽  
Polymerase Chain ◽  
Synthase Inhibitor

It is well known that pregnancy is associated with frequent gastrointestinal (GI) disorders and symptoms. Moreover, previous reports have shown that estrogen, which changes in levels during pregnancy, participates in the regulation of GI motility and is involved in the pathogenesis of various functional disorders in the stomach. The aim of the current study was to explore the changes in the expression of estrogen receptors (ERs) and examine the effect of estrogen on nitric oxide- (NO-) cyclic guanosine monophosphate (cGMP) pathway and thus relaxation in gastric smooth muscle cells (GSMC) during pregnancy. Single GSMC from early-pregnant and late-pregnant Sprague-Dawley rats were used. Protein and mRNA expression levels of ERs were measured via specifically designed enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), respectively. NO and cGMP levels were measured via specifically designed ELISA kits. Effect of estrogen on acetylcholine- (ACh-) induced contraction of single GSMC was measured via scanning micrometry in the presence or absence of the NO synthase inhibitor,N-nitro-L-arginine (L-NNA), or guanylyl cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ). Estrogen increased both NO and cGMP levels and their levels were greater in early compared to late pregnancy. Expression of ERs was greater in early compared to late pregnancy. ACh induced greater contraction of GSMC in late pregnancy compared to early pregnancy. Estrogen inhibited ACh-induced contraction in both periods of pregnancy. Importantly, pretreatment of GSMC with either L-NNA or ODQ abolished estrogen inhibitory action on muscle contraction. In conclusion, GSMC contractile behavior undergoes drastic changes in response to estrogen during pregnancy and this might explain some of the pregnancy-associated gastric disorders.

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