Decellularized Pancreas Matrix Scaffolds for Tissue Engineering Using Ductal or Arterial Catheterization

2018 ◽  
Vol 205 (2) ◽  
pp. 72-84 ◽  
Author(s):  
Javad Hashemi ◽  
Parvin Pasalar ◽  
Masoud Soleimani ◽  
Ehsan Arefian ◽  
Reza Khorramirouz ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Islet Cells ◽  
Sodium Dodecyl ◽  
3D Structure ◽  
Sprague Dawley ◽  
Efficient Procedure ◽  
Sprague Dawley Rats ◽  
High Concentrations ◽  
Great Burden

Introduction: Diabetes is known as a worldwide disease with a great burden on society. Since therapeutic options cover a limited number of target points, new therapeutic strategies in the field of regenerative medicine are considered. Bioscaffolds along with islet cells would provide bioengineered tissue as a substitute for β-cells. The perfusion-decellularization technique is considered to create such scaffolds since they mimic the compositional, architectural, and biomechanical nature of a native organ. In this study, we investigated 2 decellularization methods preserving tissue microarchitecture. Methods: Procured pancreas from Sprague-Dawley rats was exposed to different percentages of detergent for 2, 4, and 6 h after cannulation via the common bile duct or aorta. Results: High concentrations of sodium dodecyl sulfate (SDS), i.e., > 0.05%, resulted in tissue disruption or incomplete cell removal depending on the duration of exposure. In both methods, 6-h exposure to 0.05% SDS created a bioscaffold with intact extracellular matrices and proper biomechanical characteristics. Tissue-specific stainings revealed that elastic, reticular, and collagen fiber concentrations were well preserved. Quantitative findings showed that glycosaminoglycan content was slightly different, but hydroxyproline was in the range of native pancreas tissue. Dye infusion through ductal and vascular cannulation proved that the vascular network was intact, and scanning electron microscopy indicated a homogeneous porous structure. Conclusions: Using the detergent-based method, an effective and time-efficient procedure, a whole pancreas extracellular matrix bioscaffold can be developed that can be used as a 3D structure for pancreas tissue engineering-based studies and regenerative medicine applications.

scholarly journals Age-related decline in the taurine content of the skin in rodents

Amino Acids ◽  
2021 ◽  
Author(s):  
Tomohisa Yoshimura ◽  
Yuki Inokuchi ◽  
Chikako Mutou ◽  
Takanobu Sakurai ◽  
Tohru Nagahama ◽  
...  
Keyword(s):  
High Performance ◽  
Age Groups ◽  
Immunohistochemical Analysis ◽  
Sprague Dawley ◽  
Taurine Supplementation ◽  
Hairless Mice ◽  
Age Related ◽  
Sprague Dawley Rats ◽  
High Concentrations ◽  
Effects Of Aging

AbstractTaurine, a sulfur-containing amino acid, occurs at high concentrations in the skin, and plays a role in maintaining the homeostasis of the skin. We investigated the effects of aging on the content and localization of taurine in the skin of mice and rats. Taurine was extracted from the skin samples of hairless mice and Sprague Dawley rats, and the taurine content of the skin was determined by high-performance liquid chromatography (HPLC). The results of the investigation revealed that the taurine content in both the dermis and epidermis of hairless mice declined significantly with age. Similar age-related decline in the skin taurine content was also observed in rats. In contrast, the taurine content in the sole remained unchanged with age. An immunohistochemical analysis also revealed a decreased skin taurine content in aged animals compared with younger animals, although no significant differences in the localization of taurine were observed between the two age groups. Supplementation of the drinking water of aged mice with 3% (w/v) taurine for 4 weeks increased the taurine content of the epidermis, but not the dermis. The present study showed for the first time that the taurine content of the skin decreased with age in mice and rats, which may be related to the impairment of the skin homeostasis observed with aging. The decreased taurine content of the epidermis in aged animals was able to be rescued by taurine supplementation.

Characterization of vasoactive intestinal peptide receptors on rat alveolar macrophages

1994 ◽  
Vol 267 (3) ◽  
pp. L256-L262 ◽  
Author(s):  
H. Sakakibara ◽  
K. Shima ◽  
S. I. Said
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Alveolar Macrophages ◽  
Inflammatory Responses ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
High Capacity ◽  
Sprague Dawley ◽  
Major Band ◽  
High Affinity ◽  
Sprague Dawley Rats

In view of the evidence that vasoactive intestinal peptide (VIP) may modulate acute inflammatory injury in the lung, we investigated the presence and characteristics of VIP receptors on alveolar macrophages (AMs). We examined the binding of monoiodinated [Tyr(125I)10]-labeled VIP (125I-VIP) to rat AMs (> 96% pure), obtained from Sprague-Dawley rats by bronchoalveolar lavage (BAL). At 23 degrees C, the interaction of 125I-VIP with AMs was rapid, reversible, saturable, and linearly proportional to the number of cells. At equilibrium, the binding was competitively inhibited by 10(-11)-10(-6) M of native peptide [half-maximal inhibition (IC50) = 0.53 +/- 0.34 nM, n = 8], with evidence for two classes of binding sites: one with a high affinity (Kd = 0.20 +/- 0.09 nM) and a low capacity (1,190 +/- 640 sites/cell) and another with a low affinity (Kd = 43.2 +/- 13.8 nM) and a high capacity (51,700 +/- 14,000 sites/cell). VIP-related peptides inhibited the binding with the order of potency: VIP > peptide histidine isoleucine > helodermin >> secretin; glucagon was ineffective. In the presence of 3-isobutyl-1-methylxanthine, VIP dose dependently stimulated adenosine 3',5'-cyclic monophosphate accumulation in intact AMs, with maximal stimulation (6.3 times basal level) at 1 nM, and half-maximal accumulation at 0.23 +/- 0.11 nM VIP (Kd for high-affinity sites). For determination of the mass of the VIP receptor, 125I-VIP was covalently bound to AMs with the cross-linking agent dithiobis succinimidyl propionate. Autoradiographic studies after sodium dodecyl sulfate/polyacrylamide gel electrophoresis of solubilized affinity-labeled cells revealed a single major band of M(r) 76,400. We conclude that VIP binds to specific receptors on rat AMs that are coupled to adenylate cyclase, through which VIP may modulate inflammatory responses within the lung.

Decreased vascular sensitivity to norepinephrine following exercise training

1981 ◽  
Vol 51 (2) ◽  
pp. 282-287 ◽  
Author(s):  
D. L. Wiegman ◽  
P. D. Harris ◽  
I. G. Joshua ◽  
F. N. Miller
Keyword(s):  
Blood Pressure ◽  
Exercise Training ◽  
Sprague Dawley ◽  
Maximal Increase ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
Vascular Sensitivity ◽  
Series Of Experiments ◽  
High Concentrations ◽  
Alpha Chloralose

Twenty Sprague-Dawley rats (230 +/- 9 g; mean +/- SE) were exercised daily for 6 wk by swimming 1 h/day with weights (5% of body wt) attached to their tails. Nineteen additional rats (237 +/- 8 g) remained sedentary in their cages. All animals were anesthetized with urethan (800 mg/kg) and alpha-chloralose (60 mg/kg). In the first series of experiments, increasing doses of norepinephrine were injected into the jugular vein and the responses in mean arterial blood pressure was recorded from a cannulated femoral artery. Exercise training had no effect on the maximal increase in blood pressure, but significantly decreased blood pressure sensitivity to norepinephrine, expressed as a pD2 value (=-log ED 50), from 5.64 +/- 0.07 to 5.20 +/- 0.06. In the second series, the cremaster muscle with intact circulation and innervation was suspended in a tissue bath and norepinephrine in increasing concentrations was added to the cremaster bath. The responses of the main arteriole (approximately 110 micron) and venule (approximately 170 micron) were recorded by television microscopy. Exercise training had no effect on vessel diameters of resting muscle or on the maximal vessel constrictions obtained in response to high concentrations of norepinephrine. Arteriole sensitivity to norepinephrine was significantly decreased (pD2 of 6.69 +/- 0.24 vs. 5.96 +/- 0.18) and there was some tendency for reduced venule sensitivity. These data suggest that exercise training in rats produces a decrease in alpha- or an increase in beta-adrenergic receptor sensitivity.

scholarly journals A 90-Day Oral (Dietary) Toxicity Study of Rebaudioside A in Sprague-Dawley Rats

2008 ◽  
Vol 27 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Andrey I Nikiforov ◽  
Alex K Eapen
Keyword(s):  
Clinical Pathology ◽  
Stevia Rebaudiana ◽  
Rebaudioside A ◽  
Sprague Dawley ◽  
Small Magnitude ◽  
Stevia Rebaudiana Bertoni ◽  
Sprague Dawley Rats ◽  
The Difference ◽  
High Concentrations ◽  
And Behavior

Rebaudioside A is one of several glycosides found in the leaves of Stevia rebaudiana (Bertoni) Bertoni (Compositae) stevia that has been identified as a potential sweetener. The present study (initiated in April 2006 and completed in October 2006) evaluated the safety of this sweetener when administered as a dietary admix at target exposure levels of 500, 1000, and 2000 mg/kg/day to Sprague-Dawley rats for 90 days. There were no treatment-related effects on the general condition and behavior of the animals as determined by clinical observations, functional observational battery, and locomotor activity assessments. Evaluation of clinical pathology parameters revealed no toxicologically relevant, treatment-related effects on hematology, serum chemistry, or urinalysis. Macroscopic and microscopic findings revealed no treatment-related effects on any organ evaluated. Lower mean body weight gains were noted in males in the 2000 mg/kg/day group throughout the study, which was considered to be test article related; however, given the small magnitude of the difference as compared to controls, this effect was not considered to be adverse. Results of this study clearly demonstrate that dietary administration of high concentrations of rebaudioside A for 90 consecutive days to Sprague-Dawley rats was not associated with any signs of toxicity.

scholarly journals Assessment of carbon dioxide, carbon dioxide/oxygen, isoflurane and pentobarbital killing methods in rats

2016 ◽  
Author(s):  
Jessica M Chisholm ◽  
Daniel SJ Pang
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Loss Of Consciousness ◽  
Sprague Dawley ◽  
Loss Of Righting Reflex ◽  
Sprague Dawley Rats ◽  
General Order ◽  
Righting Reflex ◽  
High Concentrations ◽  
The Relationship

AbstractBackground:Exposure to carbon dioxide (CO2) gas as a killing method is aversive and exposure to high concentrations likely to be painful. Bradycardia during exposure to CO2 is associated with nociception and pain. However, it is unclear if bradycardia occurs before loss of consciousness as this is variably defined in the literature. The objectives of this study were to explore the relationship between recumbency, loss of righting reflex (LORR) and a quiescent electromyograph as measures of loss of consciousness, and identify the onset of bradycardia in relation to these measures.Methods:Thirty-two adult, female Sprague-Dawley rats were instrumented with a telemetry device and randomly assigned to one of four killing methods (100% CO2, CO2 (70%)/O2 (30%), isoflurane (5%) and intraperitoneal pentobarbital (200 mg/kg). Time to achieve recumbency, LORR, quiescent electromyograph, isoelectric electrocorticograph, heart rate and apnea were recorded.Results:The general order of progression was recumbency, LORR, quiescent electromyograph, isoelectric electrocorticograph and apnea. Recumbency preceded LORR in the majority of animals (CO2; 7/8, CO2/O2; 8/8, isoflurane; 5/8, pentobarbital; 4/8). Bradycardia occurred before recumbency in the CO2 (p = 0.0002) and CO2/O2 (p = 0.005) groups, with a 50% reduction in heart rate compared to baseline. The slowest (time to apnea) and least consistent killing methods were CO2/O2 (1180 ± 658.1s) and pentobarbital (875 [239 to 4680]s).Conclusion:Bradycardia, and consequently nociception and pain, occurs before loss of consciousness during CO2 exposure. Pentobarbital displayed an unexpected lack of consistency, questioning its classification as an acceptable euthanasia method in rats.

scholarly journals Chronic stress increases the tyrosine phosphorylation in female reproductive organs: An experimental study

2021 ◽  
Author(s):  
Sudtida Bunsueb ◽  
Natthapol Lapyuneyong ◽  
Saranya Tongpan ◽  
Supatcharee Arun ◽  
Sitthichai Iamsaard
Keyword(s):  
Experimental Study ◽  
Tyrosine Phosphorylation ◽  
Chronic Stress ◽  
Cold Water ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Reproductive Organs ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Sds Page

Background: Changes in tyrosine-phosphorylated (TyrPho) protein expressions have demonstrated stress in males. In females, chronic stress (CS) is a major cause of infertility, especially anovulation. However, the tyrosine phosphorylation in the female reproductive system under stress conditions has never been reported. Objective: To investigate the alteration of TyrPho protein expression in ovary, oviduct, and uterus of CS rats. Materials and Methods: In this experimental study, 16 female Sprague-Dawley rats (5 wk: 220-250 gr) were divided into control and CS groups (n = 8/group). Every day, the CS animals were immobilized within a restraint cage and individually forced to swim in cold water for 60 consecutive days. Following the stress induction, the ovary, oviduct, and uterus of all rats were observed for their morphologies. The total protein profiles of all tissues were revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) before detecting TyrPho proteins using western blot. Intensity analysis was used to compare the expression of proteins between groups. Results: The results showed that the morphology and weights of ovary and oviduct in the CS group were not different from control. In contrast, the CS significantly increased the uterine weight as compared to control. Moreover, the expressions of TyrPho proteins in the ovary (72, 43, and 28 kDas), oviduct (170, 55, and 43 kDas), and uterus (55, 54, and 43 kDas) were increased in CS group as compared to those of control. Conclusion: The increased expressions of TyrPho proteins in ovary, oviduct, and uterus could be potential markers used to explain some mechanisms of female infertility caused by chronic stress. Key words: Ovary, Oviduct, Uterus, Phosphorylation.

Relationship between PG and beta-adrenergic pathways to renin release in rat renal cortical slices

1984 ◽  
Vol 247 (3) ◽  
pp. E343-E348 ◽  
Author(s):  
W. L. Henrich ◽  
W. B. Campbell
Keyword(s):  
Renin Activity ◽  
Renin Release ◽  
Sprague Dawley ◽  
Beta Adrenergic ◽  
Beta Agonists ◽  
Sprague Dawley Rats ◽  
High Concentrations ◽  
Rat Renal Cortical Slices ◽  
Cortical Slices ◽  
Synergistic Increase

The precise importance of prostaglandin (PG) in the beta-adrenergic pathway to renin release is unresolved. Thus, we examined this question using renal cortical slices from Sprague-Dawley rats incubated in Krebs-Ringer bicarbonate mixture (KRB), KRB + isoproterenol (10(-5) M, ISO), or a solution containing KRB + ISO + either propranolol (PRO, 10(-5) M) or indomethacin (IN, 10(-5) M). Media samples were assayed for renin activity, 6-keto-PGF1 alpha (the stable metabolite of PGI2), and PGE2. ISO only increased renin release 1.96-fold; modest increments in 6-keto-PGF1 alpha and PGE2 also occurred. The addition of PRO prevented these increases. In the next series of studies, ISO again increased renin, but the addition of IN failed to modify this increase in renin release. However, IN did prevent any increase in 6-keto-PGF1 alpha or PGE2. Meclofenemate (10(-5) M) provided results similar to those of IN. PGI2 was found to stimulate the release of renin in concentrations of 10(-7) M. The combination of submaximal stimulatory concentrations of PGI2 (10(-6) M, a 1.6-fold increment) and ISO (10(-6) M, a 1.7-fold increment) produced a synergistic increase in renin release (2.84-fold). These results demonstrate that renal prostaglandins do not function as essential mediators of the beta-adrenergic pathway to renin release. Rather, high concentrations of prostaglandins may increase the renin-releasing action of beta-agonists, thereby modulating the release of renin.

Neuropeptide FF exerts pro- and anti-opioid actions in the parabrachial nucleus to modulate food intake

2003 ◽  
Vol 285 (5) ◽  
pp. R1046-R1054 ◽  
Author(s):  
Danielle M. Nicklous ◽  
Kenny J. Simansky
Keyword(s):  
Food Intake ◽  
Opioid Receptor ◽  
Receptor Agonist ◽  
Parabrachial Nucleus ◽  
Sprague Dawley ◽  
Neuropeptide Ff ◽  
Opioid Receptor Agonist ◽  
Sprague Dawley Rats ◽  
Μ Opioid Receptor ◽  
High Concentrations

Neurons that synthesize the morphine modulatory peptide neuropeptide FF (NPFF; Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2) densely innervate the parabrachial nucleus (PBN), an area implicated in regulating food intake. We analyzed opioid-related actions of NPFF in feeding in adult male Sprague-Dawley rats. Unilateral infusion of 2 nmol/0.5 μl of the μ-opioid receptor agonist [d-Ala2,NMe-Phe4,glycinol5]enkephalin (DAMGO) into the lateral PBN increased 4-h food intake from 0.7 ± 0.1 to 3.3 ± 0.3 g. NPFF (1.25-5.0 nmol) prevented this hyperphagic μ-opioidergic action. In rats fed after 4-h deprivation (baseline = 12.3 ± 0.3 g/2 h), 5 nmol of NPFF did not alter and larger doses (10 and 20 nmol) actually increased food intake (+36, 54%). Twenty nanomoles also elevated intake of freely feeding rats (from 0.7 ± 0.1 to 5.1 ± 1.0 g/4 h). The opioid receptor blocker naloxone (10 nmol) antagonized this increase. These data reveal both pro- and anti-opioid actions of NPFF in the PBN to modulate feeding. The mechanisms for the opposite actions of low and high concentrations of this neuropeptide in parabrachial regulation of food intake remain to be determined.

Spontaneous glomerular immunoglobulin deposition in young Sprague-Dawley rats

1988 ◽  
Vol 22 (4) ◽  
pp. 287-292 ◽  
Author(s):  
N. P. Goode ◽  
A. M. Davison ◽  
G. Gowland ◽  
M. Shires
Keyword(s):  
Immune Complexes ◽  
Age Group ◽  
Newborn Rats ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Weanling Rats ◽  
Dense Deposits ◽  
High Concentrations ◽  
Igm Deposits ◽  
Maternal Igg

The frequency, age-onset and distribution of spontaneously deposited immunoglobulins (lgs) in glomeruli of Sprague-Dawley rats has been investigated. Groups of rats ( n=10) were examined at 4-7 day intervals from birth (presuckling) until 30 days of age. Findings were compared with circulating immunoglobulin concentrations in each age group. Immunoglobulins were undetectable in immature kidneys of newborn rats. However, as early as 5 days, scanty IgA and IgM deposits were observed predominantly in mesangial areas of mature glomeruli, corresponding to low circulating concentrations of these immunoglobulins. By contrast, glomerular IgG deposits were not observed until 21 days, despite relatively high concentrations of circulating maternal IgG from birth. Mesangial deposition of immunoglobulins increased with age. Absence of complement C3c or electron dense deposits associated with this mesangial localization suggests that immunoglobulins were not deposited as immune complexes. Accumulation of non-phlogogenic immunoglobulins in the mesangium of normal rats supports the concept that the mesangium is constantly perfused by circulating macro-molecules and filtration residues. The results indicate problems of interpretation of the significance of endogenous immunoglobulin deposition in models of experimental glomerulonephritis, even in studies involving weanling rats.

scholarly journals Optimization of Complete Rat Heart Decellularization Using Artificial Neural Networks

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 79
Author(s):  
Greta Ionela Barbulescu ◽  
Taddeus Paul Buica ◽  
Iacob Daniel Goje ◽  
Florina Maria Bojin ◽  
Valentin Laurentiu Ordodi ◽  
...  
Keyword(s):  
Neural Networks ◽  
Histological Analysis ◽  
Sodium Dodecyl ◽  
Sprague Dawley ◽  
Deep Convolutional Neural Networks ◽  
Software Application ◽  
Sprague Dawley Rats ◽  
Machine Learning Approach ◽  
Image Set ◽  
Exact Moment

Whole organ decellularization techniques have facilitated the fabrication of extracellular matrices (ECMs) for engineering new organs. Unfortunately, there is no objective gold standard evaluation of the scaffold without applying a destructive method such as histological analysis or DNA removal quantification of the dry tissue. Our proposal is a software application using deep convolutional neural networks (DCNN) to distinguish between different stages of decellularization, determining the exact moment of completion. Hearts from male Sprague Dawley rats (n = 10) were decellularized using 1% sodium dodecyl sulfate (SDS) in a modified Langendorff device in the presence of an alternating rectangular electric field. Spectrophotometric measurements of deoxyribonucleic acid (DNA) and total proteins concentration from the decellularization solution were taken every 30 min. A monitoring system supervised the sessions, collecting a large number of photos saved in corresponding folders. This system aimed to prove a strong correlation between the data gathered by spectrophotometry and the state of the heart that could be visualized with an OpenCV-based spectrometer. A decellularization completion metric was built using a DCNN based classifier model trained using an image set comprising thousands of photos. Optimizing the decellularization process using a machine learning approach launches exponential progress in tissue bioengineering research.

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