Global trend and future landscape of intestinal microcirculation research from 2000 to 2021:A scientometric study

BACKGROUND The intestinal microcirculation functions in food absorption and metabolic substance exchanges.Accumulating evidence indicates that intestinal microcirculatory dysfunction is a significant source of multiple gastrointestinal diseases.To date,there has not been a scientometric analysis of intestinal microcirculatory research.AIM To investigate the current status,development trends,and frontiers of intestinal microcirculatory research based on bibliometric analysis.METHODS VOSviewer and CiteSpace 6.1.R2 were used to identify the overall characteristics and knowledge map of intestinal microcirculatory research based on the core literature published from 2000 to 2021 in the Web of Science database.The characteristics of each article,country of origin,institution,journal,cocitations,and other information were analyzed and visualized.RESULTS There were 1364 publications enrolled in the bibliometric analysis,exhibiting an upward trend from 2000 to 2021 with increased participation worldwide.The United States and Dalhousie University took the lead among countries and institutions,respectively.Shock was the most prolific journal,and Nature Reviews Microbiology Clinical had the most citations.The topical hotspots and frontiers in intestinal microcirculatory research were centered on the pathological processes of functional impairment of intestinal microvessels,diverse intestinal illnesses,and clinical treatment.CONCLUSION Our study highlights insights into trends of the published research on the intestinal microcirculation and offers serviceable guidance to researchers by summarizing the prolific areas in intestinal disease research to date.

Mesenteric lymph reperfusion may exacerbate brain injury in a rat model of superior mesenteric artery occlusion shock

BACKGROUND：The intestinal lymphatic pathway and intestinal ischemia/reperfusion are mainly involved in mesenteric lymph duct ligation or drainage; moreover,intervention by reducing the lymph liquid reflux might relieve lung and other organ dysfunction induced by intestinal ischemia/reperfusion; however,research addressing mesenteric lymph reperfusion （MLR） and brain injury has not yet to be reported.OBJECTIVE：To observe the effect of MLR on brain tissue in a rat model of superior mesenteric artery occlusion （SMAO） shock,and to explore the molecular mechanism of MLR.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment at a neuro-pathophysiology level was performed at the Institute of Microcirculation,Hebei North University; Department of Pathophysiology,Basic Medical College; Department of Pathology,the First Hospital of Hebei North University between December 2007 and March 2009.MATERIALS：Adenosine triphosphate （ATP） standard was provided by the National Institute for the Control of Pharmaceutical and Biological Products; lactic acid （LA）,superoxide dismutase （SOD）,malonaldehyde （MDA）,nitrogen monoxidum （NO）,nitric oxide synthase （NOS）,myeloperoxidase （MPO） and ATPase assay kits were provided by Nanjing Jiancheng Bioengineering Institute,China.METHODS：A total of 24 male Wistar rats were randomly divided into four groups.In the sham-surgery group （n = 6）,both the mesenteric lymph duct and the superior mesenteric artery were not blocked; in the MLR group （n = 6）,the mesenteric lymph duct was occluded for 1 hour followed by 2-hour reperfusion; in the SMAO group （n = 6）,the superior mesenteric artery was occluded for 1 hour followed by 2-hour reperfusion; in the MLR ＋ SMAO group （n = 6）,both the mesenteric lymph duct and superior mesenteric artery were occluded for 1 hour followed by 2-hour reperfusion.MAIN OUTCOME MEASURES：Mean arterial blood pressure prior to and following ischemia/reperfusion; brain tissue morphology levels of LA,MDA,SOD,NO,NOS,MPO,ATPase and ATP following reperfusion.RESULTS：MLR did not cause changes in mean arterial blood pressure,brain tissue morphology,LA,MDA,NO,ATP,SOD,NOS,MPO and ATPase.However,SMAO caused a rapid decrease and gradual increase of mean arterial blood pressure.Neuronal necrosis,degeneration and swelling were observed in brain tissue.Contents of MDA,NO,LA and ATP as well as activities of NOS and MPO were significantly increased （P〈 0.05）,but activities of SOD and Na＋-K＋-ATPase were significantly decreased （P 〈 0.05）.MLR aggravated neuronal damage in a rat model of SMAO shock.Following MLR,mean arterial blood pressure was significantly decreased （P 〈 0.05）,contents of MDA and NO as well as activities of NOS and MPO were significantly increased （P 〈0.05）,but activities of Ca2＋-ATPase,Mg2＋-ATPase and Ca2＋-Mg2＋-ATPase as well as ATP content were significantly decreased （P〈 0.05）.CONCLUSION：MLR aggravates brain injury in a rat model of SMAO shock,which correlates with oxygen-derived free radical injury,NO synthesis and release,sequestration of neutrophilic granulocytes,decreasing activity of cell membrane pumps and energy metabolism dysfunction.Pathogenesis of the intestinal lymphatic pathway should be thoroughly investigated to prevent ischemia/reperfusion injury.

Influence of mesenteric lymph reperfusion on neurotransmitter expression in brain tissue of a superior mesenteric artery occlusion shock rat model

BACKGROUND： Previous studies have shown that mesenteric lymph reperfusion （MLR） exacerbates brain injury in a rat model of superior mesenteric artery occlusion （SMAO） shock. However, little is known about the influence of MLR on neurotransmitter expression in brain tissue. OBJECTIVE： To observe the effect of MLR on brain tissue injury by measuring monoamine and cholinergic neurotransmitter levels. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Microcirculation, Hebei North University, China; Research Room of Microcirculation and Laboratory of Biochemistry, Department of Pathophysiology, Basic Medical College, Hebei North University between December 2007 and March 2009. MATERIALS： Choline acetyltransferase （CHAT） and acetylcholine esterase （ACHE） kits were provided by Nanjing Jiancheng Bioengineering Institute, China; dopamine （DA） and noradrenalin （NE） standards were provided by the National Institute for the Control of Pharmaceutical and Biological Products; HP1100 chromatograph of liquid was provided by Agllent, USA. METHODS： A total of 24 male, Wistar rats were randomly assigned to 4 groups： sham-surgery, MLR SMAO, and MLR ＋ SMAO groups, with 6 rats in each group. In the MLR or SMAO groups, the mesenteric lymph duct or superior mesenteric artery was blocked for 1 hour. In the MLR ＋ SMAO group, the mesenteric lymph duct and superior mesenteric artery were occluded for 1 hour, followed by 2-hour repeffusion. ChAT and AChE levels were measured using the synthesized and hydrolyzed acetylcholine method, respectively. Liquid chromatography was employed to quantitatively analyze DA and NE levels, using relative retention time and the external standard method. MAIN OUTCOME MEASURES： CHAT, ACHE, DA, and NE levels. RESULTS： AChE levels were significantly increased, but ChAT levels were significantly decreased in the MLR and MLR ＋ SMAO groups following 2-hour repeffusion （P〈 0.01）. However, AChE activity in the MLR ＋ SMAO group was greater than in the MLR group （P 〈 0.05）. DA and NE levels were significantly decreased in the SMAO and MLR ＋ SMAO groups （P〈 0.01）, while DA levels in the MLR ＋ SMAO group were less than in the SMAO group （P 〈 0.05）. CONCLUSION： MLR exacerbated brain injury in a rat model of SMAO shock, which correlated with the intestinal lymphatic pathway. MLR decreased DA levels, but increased AChE activity, in a rat model of SMAO shock.

Electroacupuncture at Dazhui(GV14) and Mingmen(GV4) protects against spinal cord injury:the role of the Wnt/β-catenin signaling pathway

Electroacupuncture at Dazhui（GV14） and Mingmen（GV4） on the Governor Vessel has been shown to exhibit curative effects on spinal cord injury; however, the underlying mechanism remains poorly understood. In this study, we established rat models of spinal cord injury using a modified Allen＇s weight-drop method. Ninety-nine male Sprague-Dawley rats were randomly divided into three equal groups： sham（only laminectomy）, SCI（induction of spinal cord injury at T10）, and EA（induction of spinal cord injury at T10 and electroacupuncture intervention at GV14 and GV4 for 20 minutes once a day）. Rats in the SCI and EA groups were further randomly divided into the following subgroups： 1-day（n = 11）, 7-day（n = 11）, and 14-day（n = 11）. At 1, 7, and 14 days after electroacupuncture treatment, the Basso, Beattie and Bresnahan locomotor rating scale showed obvious improvement in rat hind limb locomotor function, hematoxylin-eosin staining showed that the histological change of injured spinal cord tissue was obviously alleviated, and immunohistochemistry and western blot analysis showed that Wnt1, Wnt3 a, β-catenin immunoreactivity and protein expression in the injured spinal cord tissue were greatly increased compared with the sham and SCI groups. These findings suggest that electroacupuncture at GV14 and GV4 upregulates Wnt1, Wnt3 a, and β-catenin expression in the Wnt/β-catenin signaling pathway, exhibiting neuroprotective effects against spinal cord injury.

Role of insulin in pancreatic microcirculatory oxygen profile and bioenergetics

BACKGROUND The pancreatic islet microcirculation adapts its metabolism to cope with limited oxygen availability and nutrient delivery.In diabetes,the balance between oxygen delivery and consumption is impaired.Insulin has been proven to exert complex actions promoting the maintenance of homeostasis of the pancreas under glucotoxicity.AIM To test the hypothesis that insulin administration can improve the integrated pancreatic microcirculatory oxygen profile and bioenergetics.METHODS The pancreatic microcirculatory partial oxygen pressure(PO_(2)),relative hemoglobin(rHb)and hemoglobin oxygen saturation(SO_(2))were evaluated in nondiabetic,type 1 diabetes mellitus(T1DM),and insulin-treated mice.A threedimensional framework was generated to visualize the microcirculatory oxygen profile.Ultrastructural changes in the microvasculature were examined using transmission electron microscopy.An Extracellular Flux Analyzer was used to detect the real-time changes in bioenergetics by measuring the oxygen consumption rate and extracellular acidification rate in islet microvascular endothelial cells(IMECs).RESULTS Significantly lower PO_(2),rHb,and SO_(2) values were observed in T1DM mice than in nondiabetic controls.Insulin administration ameliorated the streptozotocin-induced decreases in these microcirculatory oxygen parameters and improved the mitochondrial ultrastructural abnormalities in IMECs.Bioenergetic profiling revealed that the IMECs did not have spare respiratory capacity.Insulin-treated IMECs exhibited significantly greater basal respiration than glucotoxicity-exposed IMECs(P<0.05).An energy map revealed increased energetic metabolism in insulin-treated IMECs,with significantly increased ATP production,non-mitochondrial respiration,and oxidative metabolism(all P<0.05).Significant negative correlations were revealed between microcirculatory SO_(2) and bioenergetic parameters.CONCLUSION Glucotoxicity deteriorates the integrated pancreatic microcirculatory oxygen profile and bioenergetics,but this deterioration can be reversed by insulin administration.

Adrenal pheochromocytoma impacts three main pathways: cysteine-methionine, pyrimidine, and tyrosine metabolism

Pheochromocytomas and paragangliomas(PPGLs)cause symptoms by altering the circulation levels of catecholamines and peptide hormones.Currently,the diagnosis of PPGLs relies on diagnostic imaging and the detection of catecholamines.In this study,we used ultra-performance liquid chromatography(UPLC)/quadrupole time-of-flight mass spectrometry(Q-TOF MS)analysis to identify and measure the perioperative differential metabolites in the plasma of adrenal pheochromocytoma patients.We identified differentially expressed genes by comparing the transcriptomic data of pheochromocytoma with the normal adrenal medulla.Through conducting two steps of metabolomics analysis,we identified 111 differential metabolites between the healthy group and the patient group,among which 53 metabolites were validated.By integrating the information of differential metabolites and differentially expressed genes,we inferred that the cysteine-methionine,pyrimidine,and tyrosine metabolism pathways were the three main metabolic pathways altered by the neoplasm.The analysis of transcription levels revealed that the tyrosine and cysteine-methionine metabolism pathways were downregulated in pheochromocytoma,whereas the pyrimidine pathway showed no significant difference.Finally,we developed an optimized diagnostic model of two metabolites,L-dihydroorotic acid and vanylglycol.Our results for these metabolites suggest that they may serve as potential clinical biomarkers and can be used to supplement and improve the diagnosis of pheochromocytoma.

Microvascular protective role of pericytes in melatonin-treated spinal cord injury in the C57BL/6 mice

Background Pericytes,located on microvessels,help to maintain vascular stability and blood-brain barrier integrity.The influence of pericytes on microvessels after spinal cord injury （SCI） is less clear.Therefore,the aim of this study was to investigate whether pericytes took a protective effect on microvessels in melatonin-treated SCI.Methods C57BL/6 mice were randomly divided into three groups：sham group,SCI group,and melatonin group （n=27per group）.Functional recovery was evaluated using the Basso Mouse Scale.Motor neurons were observed using hematoxylin and eosin staining.Pericyte coverage was analyzed using immunofluorescence.Permeability of blood-spinal cord barrier （BSCB） was assessed by administration of Evan＇s Blue.Protein levels of occludin,aquaporin-4 （AQP4）,angiopoietin-1 （Ang1）,intercellular cell adhesion molecule-1 （ICAM-1）,Bcl-2,and Bax were determined using Western blotting.Mimicking the pathological conditions of SCI,melatonin-treated primary pericytes were subjected to oxygenglucose deprivation/reperfusion （OGD/R）.Secretion of Ang1 was analyzed using an enzyme-linked immunosorbent assay,and the expression of ICAM-1 was detected by immunofluorescence.Results Melatonin treatment improved locomotor functional outcome and rescued motor neurons.Pericyte coverage was significantly reduced after SCI; melatonin treatment alleviated the loss of pericyte coverage and rescued perfused microvessels 7 days after injury.The permeability of BSCB and loss of occludin were attenuated,and edema formation and upregulation of AQP4 were inhibited,after melatonin treatment.The expression of Ang1 and Bcl-2 was improved,while the expression of ICAM-1 and Bax was inhibited,in melatonin-treated SCl mice.Furthermore,the secretion of Ang1 was increased and the expression of ICAM-1 was inhibited in melatonin-treated pericytes after OGD/R.Conclusions Melatonin ameliorated the loss of blood vessels and disruption of BSCB to exert a protective effect on SCI,which might be mediated by increased pericyte coverage.The upregulation of Ang1 in pericytes could inhibit inflammation and apoptosis to protect the microvessels.

Postconditioning of stellate ganglion block improves intestinal barrier function by inhibiting autophagy in conscious rats following hemorrhagic shock and resuscitation

To the Editor:Hemorrhagic shock is a critical pathological process characterized by microcirculation dysfunction and hypoperfusion,with severe consequences of cell damage and organ dysfunction.Intestinal barrier dysfunction is a critical link of distant organ injury caused by hemorrhagic shock.Prophylactic treatment with stellate ganglion block(SGB)significantly reduces hemorrhagic shock-induced intestinal barrier damage.