Postnatal development of myenteric neurochemical phenotype and impact on neuromuscular transmission in the rat colon

2010 ◽  
Vol 299 (2) ◽  
pp. G539-G547 ◽  
Author(s):  
P. de Vries ◽  
R. Soret ◽  
E. Suply ◽  
Y. Heloury ◽  
M. Neunlist

Profound changes in intestinal motility occur during the postnatal period, but the involvement of the enteric nervous system (ENS), a key regulator of gastrointestinal (GI) motility, in these modifications remains largely unknown. We therefore investigated the postnatal development of the ENS phenotype and determined its functional repercussion on the neuromuscular transmission in the rat colon. Sprague-Dawley rats were euthanized at postnatal day (P) 1, P3, P5, P7, P14, P21, and P36. Whole mounts of colonic myenteric plexus were stained with antibodies against choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), and HuC/D. Colonic contractile response induced by electrical field stimulation (EFS) was investigated in organ chambers in absence or presence of N-nitro-l-arginine methyl ester (l-NAME) and/or atropine. In vivo motility was assessed by measurement of the colonic bead latency time. Randomly occurring ex vivo contractions appeared starting at P5. Starting at P14, rhythmic phasic contractions occurred whose frequency and amplitude increased over time. In vivo, bead latency was significantly reduced between P14 and P21. Ex vivo, EFS-induced contractile responses increased significantly over time and were significantly reduced by atropine starting at P14 but were sensitive to l-NAME only after P21. The proportion of ChAT-immunoreactive (IR) neurons increased time dependently starting at P14. The proportion of nNOS-IR neurons increased as early as P5 compared with P1 but did not change afterward. Our data support a key role for cholinergic myenteric pathways in the development of postnatal motility and further identify them as putative therapeutic target for the treatment of GI motility disorders in the newborn.

2012 ◽  
Vol 302 (12) ◽  
pp. G1373-G1380 ◽  
Author(s):  
Etienne Suply ◽  
Philine de Vries ◽  
Rodolphe Soret ◽  
François Cossais ◽  
Michel Neunlist

Postnatal changes in the enteric nervous system (ENS) are involved in the establishment of colonic motility. In adult rats, butyrate induced neuroplastic changes in the ENS, leading to enhanced colonic motility. Whether butyrate can induce similar changes during the postnatal period remains unknown. Enemas (Na-butyrate) were performed daily in rat pups between postnatal day (PND) 7 and PND 17. Effects of butyrate were evaluated on morphological and histological parameters in the distal colon at PND 21. The neurochemical phenotype of colonic submucosal and myenteric neurons was analyzed using antibodies against Hu, choline acetyltransferase (ChAT), and neuronal nitric oxide synthase (nNOS). Colonic motility and neuromuscular transmission was assessed in vivo and ex vivo. Butyrate (2.5 mM) enemas had no impact on pup growth and histological parameters compared with control. Butyrate did not modify the number of Hu-immunoreactive (IR) neurons per ganglia. A significant increase in the proportion (per Hu-IR neurons) of nNOS-IR myenteric and submucosal neurons and ChAT-IR myenteric neurons was observed in the distal colon after butyrate enemas compared with control. In addition, butyrate induced a significant increase in both nitrergic and cholinergic components of the neuromuscular transmission compared with control. Finally, butyrate increased distal colonic transit time compared with control. We concluded that butyrate enemas induced neuroplastic changes in myenteric and submucosal neurons, leading to changes in gastrointestinal functions. Our results support exploration of butyrate as potential therapy for motility disorders in preterm infants with delayed maturation of the ENS.


2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Clare Y. L. Chao ◽  
Gabriel Y. F. Ng ◽  
Kwok-Kuen Cheung ◽  
Yong-Ping Zheng ◽  
Li-Ke Wang ◽  
...  

An evaluation of wound mechanics is crucial in reflecting the wound healing status. The present study examined the biomechanical properties of healing rat skin wounds in vivo and ex vivo. Thirty male Sprague-Dawley rats, each with a 6 mm full-thickness circular punch biopsied wound at both posterior hind limbs were used. The mechanical stiffness at both the central and margins of the wound was measured repeatedly in five rats over the same wound sites to monitor the longitudinal changes over time of before wounding, and on days 0, 3, 7, 10, 14, and 21 after wounding in vivo by using an optical coherence tomography-based air-jet indentation system. Five rats were euthanized at each time point, and the biomechanical properties of the wound tissues were assessed ex vivo using a tensiometer. At the central wound bed region, the stiffness measured by the air-jet system increased significantly from day 0 (17.2%), peaked at day 7 (208.3%), and then decreased progressively until day 21 (40.2%) as compared with baseline prewounding status. The biomechanical parameters of the skin wound samples measured by the tensiometer showed a marked reduction upon wounding, then increased with time (all p < 0.05). On day 21, the ultimate tensile strength of the skin wound tissue approached 50% of the normal skin; while the stiffness of tissue recovered at a faster rate, reaching 97% of its prewounded state. Our results suggested that it took less time for healing wound tissues to recover their stiffness than their maximal strength in rat skin. The stiffness of wound tissues measured by air-jet could be an indicator for monitoring wound healing and contraction.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1381
Author(s):  
Marilisa Straface ◽  
Raj Makwana ◽  
Alexandra Palmer ◽  
Laura Rombolà ◽  
Joanne Aleong ◽  
...  

Bergamot essential oil (BEO) added to food and drink promotes a citrus flavour. Folklore suggests benefits on gastrointestinal functions but with little supporting evidence. BEO and major constituents (linalool, limonene, linalyl acetate) were therefore examined for any ability to influence neuromuscular contractions of human and rat colon. Circular muscle strips (macroscopically-normal human colon obtained following ethical approval at cancer surgery; Sprague–Dawley rats) were suspended in baths (Krebs solution; 37 °C; 5% CO2 in O2) for measurement of neuronally-mediated contractions (prevented by tetrodotoxin or atropine) evoked by electrical field stimulation (5 Hz, 0.5 ms pulse width, 10s/minute, maximally-effective voltage), or contractions evoked by KCl (submaximally-effective concentrations). BEO and each constituent concentration dependently inhibited neuronally-mediated and KCl-induced contractions. In human: apparent pIC50 for BEO (volume/volume Krebs), respectively, 3.8 ± 0.3 and 4.4 ± 0.3; Imax 55.8% ± 4.2% and 37.5% ± 4.2%. For the constituents, the rank order of potency differed in human (linalool > limonene >> linalyl-acetate) and rat colon (linalyl-acetate > limonene = linalool), but rank order of efficacy was similar (linalool >> (BEO) = linalyl-acetate >> limonene). Thus, linalool had high efficacy but greater potency in human colon (Imax 76.8% ± 6.9%; pIC50 6.7 ± 0.2; n = 4) compared with rat colon (Imax 75.3% ± 1.9%; pIC50 5.8 ± 0.1; n = 4). The ability of BEO and linalool to inhibit human colon neuromuscular contractility provides a mechanism for use as complementary treatments of intestinal disorders.


Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3471
Author(s):  
Fatima Saqib ◽  
Muhammad Arif Aslam ◽  
Khizra Mujahid ◽  
Luigi Marceanu ◽  
Marius Moga ◽  
...  

Anogeissus acuminata (Roxb. ex DC.) is a folkloric medicinal plant in Asia; including Pakistan; used as a traditional remedy for cardiovascular disorders. This study was planned to establish a pharmacological basis for the trivial uses of Anogeissus acuminata in certain medical conditions related to cardiovascular systems and to explore the underlying mechanisms. Mechanistic studies suggested that crude extract of Anogeissus acuminata (Aa.Cr) produced in vitro cardio-relaxant and vasorelaxant effects in isolated paired atria and aorta coupled with in vivo decrease in blood pressure by invasive method; using pressure and force transducers connected to Power Lab Data Acquisition System. Moreover; Aa.Cr showed positive effects in left ventricular hypertrophy in Sprague Dawley rats observed hemodynamically by a decrease in cardiac cell size and fibrosis; along with absence of inflammatory cells; coupled with reduced levels of angiotensin converting enzyme (ACE) and renin concentration along with increased concentrations of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP). In Acute Myocardial Infarction (AMI) model; creatine kinase (CK), creatine kinase-MB (CK-MB) and lactic acid dehydrogenase (LDH levels) were found to be decreased; along with decreased necrosis; edema and recruitment of inflammatory cells histologically. In vivo and ex vivo studies of Anogeissus acuminata provided evidence of vasorelaxant; hypotensive and cardioprotective properties facilitated through blockage of voltage-gated Ca++ ion channel; validating its use in cardiovascular diseases


2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Jenny R. Roberts ◽  
Robert R. Mercer ◽  
Rebecca S. Chapman ◽  
Guy M. Cohen ◽  
Sarunya Bangsaruntip ◽  
...  

Silicon nanowires (Si NWs) are being manufactured for use as sensors and transistors for circuit applications. The goal was to assess pulmonary toxicity and fate of Si NW using anin vivoexperimental model. Male Sprague-Dawley rats were intratracheally instilled with 10, 25, 50, 100, or 250 μg of Si NW (~20–30 nm diameter; ~2–15 μm length). Lung damage and the pulmonary distribution and clearance of Si NW were assessed at 1, 3, 7, 28, and 91 days after-treatment. Si NW treatment resulted in dose-dependent increases in lung injury and inflammation that resolved over time. At day 91 after treatment with the highest doses, lung collagen was increased. Approximately 70% of deposited Si NW was cleared by 28 days with most of the Si NW localized exclusively in macrophages. In conclusion, Si NW induced transient lung toxicity which may be associated with an early rapid particle clearance; however, persistence of Si NW over time related to dose or wire length may lead to increased collagen deposition in the lung.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yoon Hee Cho ◽  
Cheol Ryong Ku ◽  
Zhen-Yu Hong ◽  
Ji Hoe Heo ◽  
Eun Hee Kim ◽  
...  

Danshen is a traditional Chinese medicine with many beneficial effects on cardiovascular diseases. The aim of this study was to evaluate the mechanisms responsible for the antiatherogenic effect of water soluble Danshen extracts (DEs). Rat vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs) were treated with DE. To evaluate the effects of DEin vivo, carotid balloon injury and tail vein thrombosis were induced in Sprague-Dawley (SD) rats and iliac artery stent was induced in New Zealand white rabbits. The inhibitory action of DE on platelet aggregation was confirmed with an impedance aggregometer. DE inhibited the production of reactive oxygen species, and the migration and proliferation of platelet-derived growth factor-BB stimulated VSMCs. Furthermore, DE prevented inflammation and apoptosis in HUVECs. Both effects of DE were reconfirmed in both rat models. DE treatment attenuated platelet aggregation in bothin vivoandex vivoconditions. Pretreatment with DE prevented tail vein thrombosis, which is normally induced byκ-carrageenan injection. Lastly, DE-treated rabbits showed decreased in-stent restenosis of stented iliac arteries. These results suggest that water soluble DE modulates key atherogenic events in VSMCs, endothelial cells, and platelets in bothin vitroandin vivoconditions.


2002 ◽  
Vol 102 (5) ◽  
pp. 541-546 ◽  
Author(s):  
Molly JACOB ◽  
Ingvar BJARNASON ◽  
Robert J. SIMPSON

The non-steroidal anti-inflammatory drugs (NSAIDs) are a widely used group of drugs in clinical medicine. However, their propensity to cause gastrointestinal damage limits their clinical utility. The pathogenesis of this toxicity is not well established. It has been postulated that an early event in the development of damage is an effect of these drugs on mitochondrial function. The present paper sets out to evaluate the effects of indomethacin, a commonly used NSAID, on energy metabolism in vivo. Indomethacin was administered to male Sprague-Dawley rats, either intrajejunally or orally, and indices of mitochondrial function were determined. The parameters chosen for this purpose were oxygen uptake by, lactate levels in and the energy charge of jejunal tissue. Oxygen uptake by and energy charge in jejunal tissue were unaffected at 1 and 3h after dosing by gavage with indomethacin. The drug significantly affected the tissue lactate/pyruvate ratio at 3h (but not at 1h) after oral dosing. Effects of indomethacin on jejunum incubated ex vivo were found to be reversible. The data suggest that indomethacin affects mitochondrial function in vivo, but that compensatory changes in glycolytic rate maintain energy charge.


2006 ◽  
Vol 291 (4) ◽  
pp. H1788-H1796 ◽  
Author(s):  
Scott S. Billecke ◽  
Laura A. Kitzmiller ◽  
Joseph J. Northrup ◽  
Steven E. Whitesall ◽  
Masumi Kimoto ◽  
...  

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.


2011 ◽  
Vol 300 (1) ◽  
pp. C198-C209 ◽  
Author(s):  
Jonathan E. Campbell ◽  
Ashley J. Peckett ◽  
Anna M. D'souza ◽  
Thomas J. Hawke ◽  
Michael C. Riddell

Glucocorticoids have been proposed to be both adipogenic and lipolytic in action within adipose tissue, although it is unknown whether these actions can occur simultaneously. Here we investigate both the in vitro and in vivo effects of corticosterone (Cort) on adipose tissue metabolism. Cort increased 3T3-L1 preadipocyte differentiation in a concentration-dependent manner, but did not increase lipogenesis in adipocytes. Cort increased lipolysis within adipocytes in a concentration-dependent manner (maximum effect at 1–10 μM). Surprisingly, removal of Cort further increased lipolytic rates (∼320% above control, P < 0.05), indicating a residual effect on basal lipolysis. mRNA and protein expression of adipose triglyceride lipase and phosphorylated status of hormone sensitive lipase (Ser563/Ser660) were increased with 48 h of Cort treatment. To test these responses in vivo, Sprague-Dawley rats were subcutaneously implanted with wax pellets with/without Cort (300 mg). After 10 days, adipose depots were removed and cultured ex vivo. Both free fatty acids and glycerol concentrations were elevated in fed and fasting conditions in Cort-treated rats. Despite increased lipolysis, Cort rats had more visceral adiposity than sham rats (10.2 vs. 6.9 g/kg body wt, P < 0.05). Visceral adipocytes from Cort rats were smaller and more numerous than those in sham rats, suggesting that adipogenesis occurred through preadipocyte differentiation rather than adipocyte hypertrophy. Visceral, but not subcutaneous, adipocyte cultures from Cort-treated rats displayed a 1.5-fold increase in basal lipolytic rates compared with sham rats ( P < 0.05). Taken together, our findings demonstrate that chronic glucocorticoid exposure stimulates both lipolysis and adipogenesis in visceral adipose tissue but favors adipogenesis primarily through preadipocyte differentiation.


2020 ◽  
Author(s):  
Mo Xian Chen ◽  
Shu Cheng ◽  
Lei Lei ◽  
Chloe U Wallis ◽  
Qiang Liu ◽  
...  

Abstract Background Prenatal exposure to selective serotonin reuptake inhibitor (SSRI), such as fluoxetine (FLX) may increase susceptibility to autism spectrum disorder (ASD). However, findings from published studies on SSRI and ASD are inconsistent. The use of a rodent model can provide a clear indication as to whether prenatal exposure to SSRIs, independent of maternal psychiatric disorders or genetic syndromes, can cause long-term behavioral and ASD-related neurobiological abnormalities in offspring. Methods FLX or normal saline (NS) was administered to pregnant Sprague-Dawley (SD) rats (FLX=30, NS=27) on gestation day 11 till birth. The resulting offspring were assessed in terms of their physical development and behavior, and underwent in vivo magnetic resonance spectroscopy ( MRS) to quantify biochemical alterations in the prefrontal cortex (PFC). Ex vivo measurements of brain serotonin level and a proteomic analysis were also undertaken. Results The offspring (male offspring in particular) of fluoxetine exposed mothers showed delayed physical development, increased anxiety and impaired social interaction. Moreover, down-regulation of 5-HT or SERT expression and up-regulation of TPH levels was observed in the PFC. We also found that prenatal FLX exposure significantly decreased NAA/tCr with 1 H-MRS in the PFC. Finally, a proteomic study revealed sex-dependent differential protein expression. ConclusionsThese findings may have translational importance suggesting that the use of SSRI medication alone in pregnant mothers may result in developmental delay and autistic-like behavior in their offspring. Our results also help to guide the choice of outcome measures in the identification of molecular and developmental mechanisms that may confer vulnerability in ASD.


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