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Reproductive Sciences (Thousand Oaks,... Apr 2021Epidemiological evidence suggests that normal pregnancy in women is associated with decreased cardiovascular risk in later life. Clinical studies have provided evidence...
Epidemiological evidence suggests that normal pregnancy in women is associated with decreased cardiovascular risk in later life. Clinical studies have provided evidence that alterations in vascular function and structure are detectable long after delivery. To understand these findings, we examined mesenteric artery reactivity at both early (3 days and 2-4 weeks) and late (12 weeks) postpartum (PP) time points in relation to late pregnancy (LP) and lactation. Vessels from virgin controls, LP, PP, and nursing and non-nursing mothers were tested for responses to phenylephrine (PE), high potassium solutions (high K), and acetylcholine (ACh). Passive arterial distensibility, vessel dimensions, and collagen and elastin content were evaluated for the studied groups. We observed that (1) there was a significant inhibition of vascular reactivity to PE in LP, 3 days and 2 weeks PP vessels that returned to pre-pregnancy levels at 4 and 12 weeks PP; (2) inhibition of NO production in PP vessels restored PE-induced constriction to pre-pregnancy levels; (3) vasodilator responses to ACh were similar at all PP periods; (4) LP and early PP was associated with a persistent increase in arterial distensibility that correlates with a PP-induced reduction in wall collagen, and regressed to pre-conception levels at 12 weeks PP; (5) vessels from non-nursing PP mice demonstrated an increased PE reactivity, diminished responses to ACh, and reduced distensibility compared to breastfeeding mice. These studies provide a timeframe for mesenteric artery adaptations that occur during pregnancy and extend to the PP period, but which may be modified by PP events.
Topics: Acetylcholine; Animals; Collagen; Elastin; Female; Lactation; Mesenteric Arteries; Mice; Phenylephrine; Postpartum Period; Potassium; Pregnancy; Vasoconstrictor Agents; Vasodilator Agents
PubMed: 33415648
DOI: 10.1007/s43032-020-00402-4 -
The Journal of Physiology Aug 2017Substantial information on rat mesenteric small artery physiology and pharmacology based on in vitro experiments is available. Little is known about the relevance of...
KEY POINTS
Substantial information on rat mesenteric small artery physiology and pharmacology based on in vitro experiments is available. Little is known about the relevance of this for artery function in vivo. We here present an intravital model where rat mesenteric small artery diameters are studied under isolated and controlled conditions in situ with simultaneous measurement of blood flow. The responses of the isolated arteries vary with the anaesthetic used, and they are quantitatively but not qualitatively different from the responses seen in vitro.
ABSTRACT
Functional characteristics of rat mesenteric small arteries (internal diameter ∼150-200 μm) have been extensively studied in vitro using isometric and isobaric myographs. In vivo, precapillary arterioles (internal diameter < 50 μm) have been studied, but only a few studies have investigated the function of mesenteric small arteries. We here present a novel approach for intravital studies of rat mesenteric small artery segments (∼5 mm long) isolated in a chamber. The agonist-induced changes in arterial diameter and blood flow were studied using video imaging and laser speckle analysis in rats anaesthetized by isoflurane, pentobarbital, ketamine-xylazine, or by a combination of fentanyl, fluanison and midazolam (rodent mixture). The arteries had spontaneous tone. Noradrenaline added to the chamber constricted the artery in the chamber but not the downstream arteries in the intestinal wall. The constriction was smaller when rats were anaesthetized by rodent mixture in comparison with other anaesthetics, where responses were qualitatively similar to those reported in vitro. The contraction was associated with reduction of blood flow, but no flow reduction was seen in the downstream arteries in the intestinal wall. The magnitude of different endothelium-dependent relaxation pathways was dependent on the anaesthesia. Vasomotion was present under all forms of anaesthesia with characteristics similar to in vitro. We have established an intravital method for studying the tone and flow in rat mesenteric arteries. The reactivity of the arteries was qualitatively similar to the responses previously obtained under in vitro conditions, but the choice of anaesthetic affects the magnitude of responses.
Topics: Acetylcholine; Anesthesia; Animals; Arginine Vasopressin; Blood Pressure; Heart Rate; Male; Mesenteric Arteries; Norepinephrine; Rats, Wistar; Regional Blood Flow; Telemetry; Vasoconstriction; Vasoconstrictor Agents; Vasodilator Agents
PubMed: 28568894
DOI: 10.1113/JP274604 -
Journal of Visualized Experiments : JoVE Sep 2011Proximal resistance vessels, such as the mesenteric arteries, contribute substantially to the peripheral resistance. These small vessels of between 100-400 μm in...
Proximal resistance vessels, such as the mesenteric arteries, contribute substantially to the peripheral resistance. These small vessels of between 100-400 μm in diameter function primarily in directing blood flow to various organs according to the overall requirements of the body. The rat mesenteric artery has a diameter greater than 100 μm. The myography technique, first described by Mulvay and Halpern(1), was based on the method proposed by Bevan and Osher(2). The technique provides information about small vessels under isometric conditions, where substantial shortening of the muscle preparation is prevented. Since force production and sensitivity of vessels to different agonists is dependent on the extent of stretch, according to active tension-length relation, it is essential to conduct contraction studies under isometric conditions to prevent compliance of the mounting wires. Stainless steel wires are preferred to tungsten wires because of oxidation of the latter, which affects recorded responses(3).The technique allows for the comparison of agonist-induced contractions of mounted vessels to obtain evidence for normal function of vascular smooth muscle cell receptors. We have shown in several studies that isolated mesenteric arteries that are contracted with phenylyephrine relax upon addition of cumulative concentrations of extracellular calcium (Ca(2+)(e;)). The findings led us to conclude that perivascular sensory nerves, which express the G protein-coupled Ca(2+)-sensing receptor (CaR), mediate this vasorelaxation response. Using an automated wire myography method, we show here that mesenteric arteries from Wistar, Dahl salt-sensitive(DS) and Dahl salt-resistant (DR) rats respond differently to Ca(2+)(e;). Tissues from Wistar rats showed higher Ca(2+)-sensitivity compared to those from DR and DS. Reduced CaR expression in mesenteric arteries from DS rats correlates with reduced Ca(2+)(e;)-induced relaxation of isolated, pre-contracted arteries. The data suggest that the CaR is required for relaxation of mesenteric arteries under increased adrenergic tone, as occurs in hypertension, and indicate an inherent defect in the CaR signaling pathway in Dahl animals, which is much more severe in DS. The method is useful in determining vascular reactivity ex vivo in mesenteric resistance arteries and similar small blood vessels and comparisons between different agonists and/or antagonists can be easily and consistently assessed side-by-side(6,7,8).
Topics: Animals; Mesenteric Arteries; Myography; Rats; Rats, Wistar; Vasoconstriction; Vasodilation
PubMed: 21969063
DOI: 10.3791/3119 -
European Radiology Jun 2021A practical screening tool for chronic mesenteric ischemia (CMI) could facilitate early recognition and reduce undertreatment and diagnostic delay. This study explored...
OBJECTIVE
A practical screening tool for chronic mesenteric ischemia (CMI) could facilitate early recognition and reduce undertreatment and diagnostic delay. This study explored the ability to discriminate CMI from non-CMI patients with a mesenteric artery calcium score (MACS).
METHODS
This retrospective study included CTAs of consecutive patients with suspected CMI in a tertiary referral center between April 2016 and October 2019. A custom-built software module, using the Agatston definition, was developed and used to calculate the MACS for the celiac artery (CA), superior mesenteric artery (SMA), and inferior mesenteric artery. Scoring was performed by two blinded observers. Interobserver agreement was determined using 39 CTAs scored independently by both observers. CMI was defined as sustained symptom improvement after treatment. Non-CMI patients were patients not diagnosed with CMI after a diagnostic workup and patients not responding to treatment.
RESULTS
The MACS was obtained in 184 patients, 49 CMI and 135 non-CMI. Interobserver agreement was excellent (intraclass correlation coefficient 0.910). The MACS of all mesenteric arteries was significantly higher in CMI patients than in non-CMI patients. ROC analysis of the combined MACS of CA + SMA showed an acceptable AUC (0.767), high sensitivity (87.8%), and high NPV (92.1%), when using a ≥ 29.7 CA + SMA MACS cutoff. Comparison of two CTAs, obtained in the same patient at different points in time with different scan and reconstruction parameters, was performed in 29 patients and revealed significant differences in MACSs.
CONCLUSION
MACS seems a promising screening method for CMI, but correction for scan and reconstruction parameters is warranted.
KEY POINTS
• A mesenteric artery calcium score obtained in celiac artery and superior mesenteric artery has a high negative predictive value for chronic mesenteric ischemia and could serve as a screening tool. • Interobserver agreement of the mesenteric artery calcium score is excellent. • Scan and reconstruction parameters influence the mesenteric artery calcium score and warrant the development of a method to correct for these parameters.
Topics: Calcium; Celiac Artery; Chronic Disease; Delayed Diagnosis; Humans; Ischemia; Mesenteric Arteries; Mesenteric Artery, Superior; Mesenteric Ischemia; Mesenteric Vascular Occlusion; Retrospective Studies; Stents; Treatment Outcome
PubMed: 33263162
DOI: 10.1007/s00330-020-07530-0 -
Journal of Vascular Surgery Apr 2012The purpose of this study was to describe the incidence, management, and outcomes of mesenteric artery complications (MACs) during angioplasty and stent placement (MAS)... (Comparative Study)
Comparative Study
OBJECTIVE
The purpose of this study was to describe the incidence, management, and outcomes of mesenteric artery complications (MACs) during angioplasty and stent placement (MAS) for chronic mesenteric ischemia (CMI).
METHODS
We retrospectively reviewed the clinical data of 156 patients treated with 173 MAS for CMI (1998-2010). MACs were defined as procedure-related mesenteric artery dissection, stent dislodgement, embolization, thrombosis, or perforation. End points were procedure-related morbidity and death.
RESULTS
There were 113 women and 43 men (mean age, 73 ± 14 years). Eleven patients (7%) developed 14 MACs, including distal mesenteric embolization in six, branch perforation in three, dissection in two, stent dislodgement in two, and stent thrombosis in one. Five patients required adjunctive endovascular procedures, including in two patients each, catheter-directed thrombolysis or aspiration, retrieval of dislodged stents, and placement of additional stents for dissection. Five patients (45%) required conversion to open repair: two required evacuation of mesenteric hematoma, two required mesenteric revascularization, and one required bowel resection. There were four early deaths (2.5%) due to mesenteric embolization or myocardial infarction in two patients each. Patients with MACs had higher rates of mortality (18% vs 1.5%) and morbidity (64% vs 19%; P <.05) and a longer hospital length of stay (6.3 ± 4.2 vs 1.6 ± 1.2 days) than those without MACs. Periprocedural use of antiplatelet therapy was associated with lower risk of distal embolization or vessel thrombosis (odds ratio, 0.2; 95% confidence interval, 0.06-0.90). Patients treated by a large-profile system had a trend toward more MACs (odds ratio, 1.8; 95% confidence interval, 0.7-26.5; P = .07).
CONCLUSIONS
MACs occurred in 7% of patients who underwent MAS for CMI and resulted in higher mortality, morbidity, and longer hospital length of stay. Use of antiplatelet therapy reduced the risk of distal embolization or vessel thrombosis. There was a trend toward more MACs in patients who underwent interventions performed with a large-profile system.
Topics: Aged; Aged, 80 and over; Angioplasty; Angioplasty, Balloon; Atherosclerosis; Chronic Disease; Cohort Studies; Confidence Intervals; Female; Follow-Up Studies; Humans; Ischemia; Male; Mesenteric Arteries; Mesenteric Vascular Occlusion; Mesentery; Middle Aged; Odds Ratio; Radiography; Retrospective Studies; Risk Assessment; Statistics, Nonparametric; Stents; Survival Rate; Treatment Outcome; Vascular Patency
PubMed: 22322121
DOI: 10.1016/j.jvs.2011.10.122 -
Journal of Vascular Surgery May 2014Mesenteric artery dissection was once thought to be rare but has been identified more frequently with increasing use of computerized tomographic angiographic imaging.... (Review)
Review
OBJECTIVE
Mesenteric artery dissection was once thought to be rare but has been identified more frequently with increasing use of computerized tomographic angiographic imaging. Multiple reports advocate a wide range of treatment including medical therapy, endovascular, and surgical intervention, with no clear guidelines for the application of each treatment.
METHODS
A systematic review of the literature was analyzed and used to create a treatment algorithm that was applied to nine patients in our institution.
RESULTS
Although medical therapy is adequate for most patients with mesenteric artery dissection, 14% failed medical therapy, sometimes with severe consequences. Asymptomatic status on presentation predicted successful medical therapy for superior mesenteric artery dissection (P = .0037).
CONCLUSIONS
Intensive surveillance is indicated during medical therapy, and invasive intervention may be necessary.
Topics: Adult; Aged; Aged, 80 and over; Algorithms; Aortic Dissection; Cardiovascular Agents; Critical Pathways; Endovascular Procedures; Female; Humans; Male; Mesenteric Arteries; Middle Aged; Patient Selection; Tomography, X-Ray Computed; Treatment Outcome; Vascular Surgical Procedures
PubMed: 24655752
DOI: 10.1016/j.jvs.2014.01.040 -
The Israel Medical Association Journal... Sep 2021Among dialysis patients, occlusive mesenteric vascular disease has rarely been reported.
BACKGROUND
Among dialysis patients, occlusive mesenteric vascular disease has rarely been reported.
OBJECTIVES
To report on the experience of one center with regard to diagnosing and treating this complication.
METHODS
The retrospective case-series involved six patients (3 females, 3 males; age 52-88 years; 5/6 were smokers) on chronic hemodialysis at a single center. All patients with symptoms suggestive of occlusive mesenteric disease and a subsequent angiographic intervention were included. Demographic, clinical, and laboratory data were collected from patient charts for the period before and after angioplasty and stenting of the mesenteric vessels. A Wilcoxon signed-rank test was used to compare the relevant data before and after the intervention.
RESULTS
All participants had variable co-morbidities and postprandial abdominal pain, food aversion, and weight loss. CT angiography was limited due to heavy vascular calcifications. All underwent angioplasty with stenting of the superior mesenteric artery (4 patients) or the celiac artery (2 patients). All procedures were successful in resolving abdominal pain, malnutrition, and inflammation. Weight loss before was 15 ± 2 kg and weight gain after was 6 ± 2 kg. C-reactive protein decreased from 13.4 ± 5.2 mg/dl to 2.2 ± 0.4 mg/dl (P < 0.05). Serum albumin increased from 3.0 ± 0.2 g/dl to 3.9 ± 0.1 g/dl (P < 0.05). Two patients underwent a repeat procedure (4 years, 5 months, respectively). Follow-up ranged from 0.5-7 years.
CONCLUSIONS
Occlusive mesenteric ischemia occurs among dialysis patients. The diagnosis requires a high degree of suspicion, and it is manageable by angiography and stenting of the most involved mesenteric artery.
Topics: Abdominal Pain; Aged; Aged, 80 and over; Angioplasty; Celiac Artery; Female; Follow-Up Studies; Humans; Male; Mesenteric Arteries; Mesenteric Ischemia; Mesenteric Vascular Occlusion; Middle Aged; Renal Dialysis; Retrospective Studies; Stents
PubMed: 34472237
DOI: No ID Found -
Surgical and Radiologic Anatomy : SRA Dec 2012In 114 cases of the transverse colon isolated from cadavers (50 male, 64 female), anatomical examinations of the arterial system of the colon were performed....
In 114 cases of the transverse colon isolated from cadavers (50 male, 64 female), anatomical examinations of the arterial system of the colon were performed. Arteriograms were obtained after dissecting and contrasting the colonic vessels with Mixobar contrast. In one case, on arteriography of the colon with its mesentery isolated from a 55-year-old male cadaver, a rare anatomical variant was found. The third mesenteric artery originated directly from the aorta-halfway between the superior and inferior mesenteric arteries and ascended obliquely in the direction of the hepatic flexure of the colon. Supply area of the artery was typical for the middle colic branch of the superior mesenteric artery: the distal segment of the ascending colon and the transverse colon. Such a variation, although very rare, may have particular impact on diagnosis and even the method and range of surgery.
Topics: Cadaver; Colon; Contrast Media; Female; Humans; Male; Mesenteric Arteries; Middle Aged
PubMed: 22820922
DOI: 10.1007/s00276-012-0987-y -
Anatomical Record (Hoboken, N.J. : 2007) Feb 2021The arterial supply of the cat jejunum was studied by gross dissection and polyurethane corrosion cast. The results showed that the jejunal arteries, which originate...
The arterial supply of the cat jejunum was studied by gross dissection and polyurethane corrosion cast. The results showed that the jejunal arteries, which originate from the cranial mesenteric artery, varied from 5 to 15 in number. Their number was independent of the length of the cranial mesenteric artery as well as of the length of the jejunum. These arteries divided into branches giving rise to a series of orders of division from a minimum of 1 to a maximum of 7. The last orders of division terminated in a series of anastomosing arcades which resulted in a marginal artery coursing only a few millimeters from the mesenteric margin of the jejunum. This artery gave rise to straight arteries (vasa recta), whose mean number was 450 ± 60. According to their length, the vasa recta can be differentiated into short (vasa brevia) and long (vasa longa) branches. The vasa brevia ended branching into the mesenteric side of the jejunum whereas the vasa longa coursed beneath the serosa on the lateral jejunal surfaces, and reached the antimesenteric border. During their course, the vasa recta ramified and anastomosed with each other. Numerous antimesenteric anastomoses between opposing vasa longa were also observed. Based on the literature consulted, due to the large number of vasa recta (approximately one vessel per 2.9 mm of jejunal length) and the rich anastomotic network, the cat jejunum might have a better intramural distribution of blood flow and would seem less predisposed to ischemic phenomena than that of other mammals.
Topics: Animals; Cats; Jejunum; Mesenteric Arteries
PubMed: 32396681
DOI: 10.1002/ar.24421 -
Pharmacological Research Jan 2022The vasculature constantly experiences distension/pressure exerted by blood flow and responds to maintain homeostasis. We hypothesized that activation of the stretch...
The vasculature constantly experiences distension/pressure exerted by blood flow and responds to maintain homeostasis. We hypothesized that activation of the stretch sensitive, non-selective cation channel Piezo1 would directly increase vascular contraction in a way that might be modified by perivascular adipose tissue (PVAT). The presence and function of Piezo1 was investigated by RT-PCR, immunohistochemistry, and isolated tissue bath contractility. Superior and mesenteric resistance arteries, aortae, and their PVATs from male Sprague Dawley rats were used. Piezo1 mRNA was detected in aortic vessels, aortic PVAT, mesenteric vessels, and mesenteric PVAT. Both adipocytes and stromal vascular fraction of mesenteric PVAT expressed Piezo1 mRNA. In PVAT, expression of Piezo1 mRNA was greater in magnitude than that of Piezo2, transient receptor potential cation channel, subfamily V, member 4 (TRPV4), anoctamin 1, calcium activated chloride channel (TMEM16), and Pannexin1 (Panx1). Piezo1 protein was present in endothelium and PVAT of rat aortic and in PVAT of mesenteric artery. The Piezo1 agonists Yoda1 and Jedi2 (1 nM - 10 µM) did not stimulate aortic contraction [max < 10% phenylephrine (PE) 10 µM contraction] or relaxation in tissues + or -PVAT. Depolarizing the aorta by modestly elevated extracellular K did not unmask aortic contraction to Yoda1 (max <10% PE 10 µM contraction). Finally, the Piezo1 antagonist Dooku1 did not modify PE-induced aorta contraction + or -PVAT. Surprisingly, Dooku1 directly caused aortic contraction in the absence (Dooku1 =26 ± 11; Vehicle = 11 ± 11%PE contraction) but not in the presence of PVAT (Dooku1 = 2 ± 1; Vehicle = 8 ± 5% PE contraction). Thus, Piezo1 is present and functional in the isolated rat aorta but does not serve direct vascular contraction with or without PVAT. We reaffirmed the isolated mouse aorta relaxation to Yoda1, indicating a species difference in Piezo1 activity between mouse and rat.
Topics: Adipose Tissue; Animals; Aorta, Thoracic; Male; Membrane Proteins; Mesenteric Arteries; Mice, Inbred C57BL; Rats, Sprague-Dawley; Vasoconstriction; Mice; Rats
PubMed: 34818570
DOI: 10.1016/j.phrs.2021.105995