Bladder reconstruction using autologous smooth muscle cell sheets grafted on a pre-vascularized capsule.

Rationale: Construction of functional vascularized three-dimensional tissues has been a longstanding objective in the field of tissue engineering. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate functional vascularized smooth muscle tissue flaps for bladder reconstruction in a rabbit model was tested. Methods: Skin tissue expanders were inserted into the groin to induce vascularized capsule pouch formation. Smooth muscle cells and endothelial progenitor cells were harvested and cocultured to form pre-vascularized smooth muscle cell sheet. Then repeated transplantation of triple-layer cell sheet grafts onto the vascularized capsular tissue was performed at 2-day intervals to prefabricate functional vascularized smooth muscle tissue flaps. Bladder muscular wall defects were created and repaired by six-layer cell sheet graft (sheet only), capsule flap (capsule only) and vascularized capsule prelaminated with smooth muscle cell sheet (sheet plus capsule). The animals were followed for 3 months after implantation and their bladders were explanted serially. Results: Bladder capacity and compliance were maintained in sheet plus capsule group throughout the 3 months. Tissue bath stimulation demonstrated that contractile responses to carbachol and KCl among the three groups revealed a significant difference (p < 0.05). Histologically, inflammation was evident in the capsule only group at 1 month and fibrosis was observed in sheet only group at 3 months. The vessel density in capsule only and sheet plus capsule group were significantly higher than in the sheet only group at each time point (p < 0.05). Comparison of the smooth muscle content among the three groups revealed a significant difference (p < 0.05). Conclusion: These results proved that the capsule may serve as an induced vascular bed for vascularized smooth muscle tissue flap prefabrication. The prefabricated functional vascularized smooth muscle tissue flap has the potential for reliable bladder reconstruction and may create new opportunities for vascularization in 3-D tissue engineering.

Histopathologic Spectrum of Neuromuscular and Vascular Hamartoma With Special Reference to the Vasculopathic Phenomenon.

Neuromuscular and vascular hamartoma (NMVH) is an unusual lesion presenting as intestinal obstruction by stricture formation. It is characterized by a hamartomatous mass comprising haphazardly arranged mesenchymal tissue native to the intestinal mucosa and submucosa. We aimed to characterize the clinicohistopathological spectrum of NMVH in adult subjects with a search for an etiological clue. We reviewed 84 resected specimens (adult cases) of intestinal obstruction in our institute and diagnosed 4 cases with NMVH. A panel of special stains (Masson trichrome, Verhoeff-van-Gieson, and periodic acid-Schiff) and immunohistochemistry (smooth muscle actin, S100, Bcl2, CD34, vimentin, desmin, CD117, and CD3) were performed in all cases. All cases of NMVH showed characteristic hamartomatous mounds comprising haphazardly arranged smooth muscle, nerves, ganglia, vessels, and collagen with overlying mucosal ulceration. Adjacent bowel showed submucosal fibrosis, muscularis mucosae thickening, and duplication along with vasculopathy. A typical vasculopathy ("vessel-in-vessel" appearance) was seen in the submucosal and/or subserosal veins. Besides, different other forms of vasculopathic changes like obliterative venopathy and concentric myohypertrophy were also seen. One case had vasculitis and the patient died despite successful surgery. One other case was associated with lymphocytic ganglioneuronitis and granulomatous etiology. We conclude that NMVH can be multifactorial in origin although ischemia resulting from vasculopathy appears to be directly causative. The characteristic vasculopathy in the submucosal location may aid in the diagnosis of NMVH in small biopsy samples.

Construction of Pedicled Smooth Muscle Tissues by Combining the Capsule Tissue and Cell Sheet Engineering.

The survival of engineered tissue requires the formation of its own capillary network, which can anastomose with the host vasculature after transplantation. Currently, while many strategies, such as modifying the scaffold material, adding endothelial cells, or angiogenic factors, have been researched, engineered tissue implanted in vivo cannot timely access to sufficient blood supply, leading to ischemic apoptosis or shrinkage. Constructing vascularized engineered tissue with its own axial vessels and subsequent pedicled transfer is promising to solve the problem of vascularization in tissue engineering. In this study, we used the tissue expander capsule as a novel platform for vascularizing autologous smooth muscle cell (SMC) sheets and fabricating vascularized engineered tissue with its own vascular pedicle. First, we verified which time point was the most effective for constructing an axial capsule vascular bed. Second, we compared the outcome of SMC sheet transplantation onto the expander capsule and classical dorsal subcutaneous tissue, which was widely used in other studies for vascularization. Finally, we transplanted multilayered SMC sheets onto the capsule bed twice to verify the feasibility of fabricating thick pedicled engineered smooth muscle tissues. The results indicated that the axial capsule tissue could be successfully induced, and the capsule tissue 1 week after full expansion was the most vascularized. Quantitative comparisons of thickness, vessel density, and apoptosis of cell sheet grafts onto two vascular beds proved that the axial capsule vascular bed was more favorable to the growth and vascularization of transplants than classical subcutaneous tissue. Furthermore, thick vascularized smooth muscle tissues with the vascular pedicle could be constructed by multi-transplanting cell sheets onto the capsule bed. The combination of axial capsule vascular bed and cell sheet engineering may provide an efficient strategy to overcome the problem of slow or insufficient vascularization in tissue engineering.

Effects of montelukast on human nasal mucosa.

OBJECTIVE: Montelukast is a selective and orally active leukotriene D4 receptor antagonist often used in treating asthma and allergic rhinitis. Montelukast nasal spray was developed to avoid systemic adverse effects of the drug in vitro. However, the effects of montelukast on human nasal mucosa are not yet fully explored and potential nasal vascular side effects of the drug merit further exploration. First, the effects of montelukast on vasocontractile responses generated by smooth muscles in the vascular structures of human nasal mucosa were investigated directly in vitro. METHODS: This study examined the effects of montelukast on human nasal mucosa in terms of mucosa resting tension, vasoconstriction caused by 10- 6 M methoxamine as a sympathetic mimetic, and electrically induced vasoconstrictions. RESULTS: The results indicated that addition of methoxamine to the incubation medium caused the nasal mucosa to vasocontract in a dose-dependent manner. Addition of montelukast at doses of 10- 5 M or above elicited a significant vasodilation response to 10- 6 M methoxamine-induced vasoconstriction. Montelukast could not inhibit electrical field stimulation-induced spike vasoconstriction. Moreover, increase in concentration of montelukast had minimal effect on basal tension of nasal mucosa. CONCLUSIONS: The study indicated significant vasodilation on human nasal mucosa under high concentrations of montelukast with a probable α-adrenoceptor antagonism. Hence, the nasal activity of α-adrenergic agonist nasal spray for nasal obstruction may be reduced in those using concomitant (oral or local spray) montelukast.

Harvesting prevascularized smooth muscle cell sheets from common polystyrene culture dishes.

Cell sheet engineering has recently emerged as a promising strategy for scaffold-free tissue engineering. However, the primary method of harvesting cell sheets using temperature-responsive dishes has potential limitations. Here we report a novel cell sheet technology based on a coculture system in which SMCs are cocultured with EPCs on common polystyrene dishes. We found that an intact and highly viable cell sheet could be harvested using mechanical methods when SMCs and EPCs were cocultured on common polystyrene dishes at a ratio of 6:1 for 5 to 6 days; the method is simple, cost-effective and highly repeatable. Moreover, the cocultured cell sheet contained capillary-like networks and could secrete a variety of angiogenic factors. Finally, in vivo studies proved that the cocultured cell sheets were more favorable for the fabrication of vascularized smooth muscle tissues compared to single SMC sheets. This study provides a promising avenue for smooth muscle tissue engineering.

Vasodilator Activity of Compounds Isolated from Plants Used in Mexican Traditional Medicine.

Arterial hypertension is one of the main risk factors in the development of cardiovascular diseases. Therefore, it is important to look for new drugs to treat hypertension. In this study, we carried out the screening of 19 compounds (triterpenes, diterpenes, sesquiterpenes, lignans, and flavonoids) isolated from 10 plants used in Mexican traditional medicine to determine whether they elicited vascular smooth muscle relaxation and, therefore, could represent novel anti-hypertension drug candidates. The vasorelaxant activity of these compounds was evaluated on the isolated rat aorta assay and the results obtained from this evaluation showed that three compounds induced a significant vasodilatory effect: meso-dihydroguaiaretic acid [half maximal effective concentration (EC50), 49.9 ± 11.2 µM; maximum effect (Emax), 99.8 ± 2.7%]; corosolic acid (EC50, 108.9 ± 6.7 µM; Emax, 96.4 ± 4.2%); and 5,8,4'-trihydroxy-3,7-dimethoxyflavone (EC50, 122.3 ± 7.6 µM; Emax, 99.5 ± 5.4%). Subsequently, involvement of the NO/cyclic guanosine monophosphate (cGMP) and H2S/ATP-sensitive potassium channel (KATP) pathways on the vasodilator activity of these compounds was assessed. The results derived from this analysis showed that the activation of both pathways contributes to the vasorelaxant effect of corosolic acid. On the other hand, the vasodilator effect of meso-dihydroguaiaretic acid and 5,8,4'-trihydroxy-3,7-dimethoxyflavone, partly involves stimulation of the NO/cGMP pathway. However, these compounds also showed an important endothelium-independent vasorelaxant effect, whose mechanism of action remains to be clarified. This study indicates that meso-dihydroguaiaretic acid, corosolic acid, and 5,8,4'-trihydroxy-3,7-dimethoxyflavone could be used as lead compounds for the synthesis of new derivatives with a higher potency to be developed as drugs for the prevention and treatment of cardiovascular diseases.

Hypoxic conditioning in blood vessels and smooth muscle tissues: effects on function, mechanisms, and unknowns.

Hypoxic preconditioning, the protective effect of brief, intermittent hypoxic or ischemic episodes on subsequent more severe hypoxic episodes, has been known for 30 yr from studies on cardiac muscle. The concept of hypoxic preconditioning has expanded; excitingly, organs beyond the heart, including the brain, liver, and kidney, also benefit. Preconditioning of vascular and visceral smooth muscles has received less attention despite their obvious importance to health. In addition, there has been no attempt to synthesize the literature in this field. Therefore, in addition to overviewing the current understanding of hypoxic conditioning, in the present review, we consider the role of blood vessels in conditioning and explore evidence for conditioning in other smooth muscles. Where possible, we have distinguished effects on myocytes from other cell types in the visceral organs. We found evidence of a pivotal role for blood vessels in conditioning and for conditioning in other smooth muscle, including the bladder, vascular myocytes, and gastrointestinal tract, and a novel response in the uterus of a hypoxic-induced force increase, which helps maintain contractions during labor. To date, however, there are insufficient data to provide a comprehensive or unifying mechanism for smooth muscles or visceral organs and the effects of conditioning on their function. This also means that no firm conclusions can be drawn as to how differences between smooth muscles in metabolic and contractile activity may contribute to conditioning. Therefore, we have suggested what may be general mechanisms of conditioning occurring in all smooth muscles and tabulated tissue-specific mechanistic findings and suggested ideas for further progress.

Luminally polarized mural and vascular remodeling in ileal strictures of Crohn's disease.

Intestinal stricture, a major complication of Crohn's disease (CD), results from fibromuscular remodeling and expansion of the intestinal wall. The corresponding microanatomical alterations have not been fully described, hindering progress toward understanding their pathogenesis and devising appropriate treatments. We used tissue-specific staining and quantitative digital histomorphometry for this purpose. Serial histologic sections from 37 surgically resected ileal strictures and adjacent nonstrictured controls from patients with CD were evaluated after staining for smooth muscle actin, collagen (Sirius red), and collagen types I, III, and V. Overall mural thickening in strictures was increased 2.2 ±â€¯0.2-fold compared with nonstrictured regions of the same specimens. The muscular layer most altered was the muscularis mucosae (MM). Compared with the internal and external layers of the muscularis propria, (MP) which were expanded 1.9 ±â€¯0.2- and 1.3 ±â€¯0.1-fold, respectively, the MM was expanded 17.7 ±â€¯2.6-fold, reflecting the combined effects of architectural disarray, an 11.6 ±â€¯1.4-fold increase smooth muscle content, and elaboration of pericellular type V collagen. In contrast, the architecture of the MP was preserved and pericellular collagen was virtually absent; rather, fibrosis in this layer was limited to expansion of the intramuscular septa by collagen types I and III. The muscular arteries and veins within the strictured submucosa frequently exhibited eccentric, luminally oriented adventitial mantles comprising hyperplastic myocytes and extracellular type V collagen. We conclude that the fibromuscular remodeling which results in CD-associated ileal strictures predominantly involves the MM and submucosal vasculature in a luminally polarized fashion and suggests that mucosal-based factors may contribute to stricture pathogenesis.

The Role of the Mucosa in Normal and Abnormal Bladder Function.

The internal face of the detrusor smooth muscle wall of the urinary bladder is covered by a mucosa, separating muscle from the hostile environment of urine. However, the mucosa is more than a very low permeability structure and offers a sensory function that monitors the extent of bladder filling and composition of the urine. The mucosa may be considered as a single functional structure and comprises a tight epithelial layer under which is a basement membrane and lamina propria. The latter region itself is a complex of afferent nerves, blood vessels, interstitial cells and in some species including human beings a muscularis mucosae. Stress on the bladder wall through physical or chemical stressors elicits release of chemicals, such as ATP, acetylcholine, prostaglandins and nitric oxide that modulate the activity of either afferent nerves or the muscular components of the bladder wall. The release and responses are graded so that the mucosa forms a dynamic sensory structure, and there is evidence that the gain of this system is increased in pathologies such as overactive bladder and bladder pain syndrome. This system therefore potentially provides a number of drug targets against these conditions, once a number of fundamental questions are answered. These include how is mediator release regulated; what are the intermediate roles of interstitial cells that surround afferent nerves and blood vessels; and what is the mode of communication between urothelium and muscle - by diffusion of mediators or by cell-to-cell communication?

Silodosin, an α(1A)-Adrenoceptor Antagonist, May Ameliorate Ischemia-Induced Bladder Denervation and Detrusor Dysfunction by Improving Bladder Blood Flow.

BACKGROUND/AIMS: This study was performed to investigate the detailed mechanism underlying the effects of the selective α(1A)-adrenoceptor antagonist, silodosin, on bladder function in a rat model of atherosclerosis-induced chronic bladder ischemia (CBI). METHODS: The CBI model was prepared by balloon endothelial injury of the bilateral iliac arteries in male rats. Using an osmotic pump, the CBI rats received either silodosin or vehicle alone subcutaneously for 8 weeks. Rats received a 2% cholesterol diet throughout the experiment. Bladder blood flow (BBF) was measured. Immunohistochemical staining was performed to determine the nerve distribution and nerve growth factor expression in the bladder. Bladders were used for muscle strip contraction analysis. The expression levels of muscarinic M2 and M3 receptors were measured. RESULTS: Silodosin abrogated the decrease in BBF in CBI rats. Silodosin prevented the decrease in nerve distribution and increase in nerve growth factor expression in the CBI model. Bladder contractile response was reduced in the CBI group. Silodosin ameliorated the effect on the bladder contractile response. The level of muscarinic M3 receptor mRNA present in the bladder of CBI rats was increased by silodosin. CONCLUSION: The results of this study suggest that silodosin ameliorates the denervation of the bladder and effects on detrusor contractile function under ischemic conditions by restoring BBF.

The Role of Nitric Oxide and Hydrogen Sulfide in Urinary Tract Function.

This MiniReview focuses on the role played by nitric oxide (NO) and hydrogen sulfide (H2 S) in physiology of the upper and lower urinary tract. NO and H2 S, together with carbon monoxide, belong to the group of gaseous autocrine/paracrine messengers or gasotransmitters, which are employed for intra- and intercellular communication in almost all organ systems. Because they are lipid-soluble gases, gaseous transmitters are not constrained by cellular membranes, so that their storage in vesicles for later release is not possible. Gasotransmitter signals are terminated by falling concentrations upon reduction in production that are caused by reacting with cellular components (essentially reactive oxygen species and NO), binding to cellular components or diffusing away. NO and, more recently, H2 S have been identified as key mediators in neurotransmission of the urinary tract, involved in the regulation of ureteral smooth muscle activity and urinary flow ureteral resistance, as well as by playing a crucial role in the smooth muscle relaxation of bladder outlet region. Urinary bladder function is also dependent on integration of inhibitory mediators, such as NO, released from the urothelium. In the bladder base and distal ureter, the co-localization of neuronal NO synthase with substance P and calcitonin gene-related peptide in sensory nerves as well as the existence of a high nicotinamide adenine dinucleotide phosphate-diaphorase activity in dorsal root ganglion neurons also suggests the involvement of NO as a sensory neurotransmitter.

Intravital Microscopy in the Cremaster Muscle Microcirculation for Endothelial Dysfunction Studies.

The intravital microscopy in the mouse cremaster muscle microcirculation is a method widely used to visualize in vivo blood cells interacting with the endothelium and within the vessels. Therefore, it is a suitable technique to study leukocyte-endothelial cell interactions along every stage of the canonical leukocyte recruitment cascade: rolling, adhesion, intravascular crawling, and migration both in postcapillary venules and arterioles of the mouse cremasteric microcirculation. This technique also enables to assess vessel functionality, since hemodynamic parameters such as shear stress, flow rate, and vasodilatation/vasoconstriction, among other vascular events, can be additionally determined. Furthermore, response to multiple drugs and mechanisms underlying blood cells interactions within the vascular system can be studied in a real scenario. This chapter describes a protocol for intravital microscopy in the mouse cremaster muscle microcirculation.

Peripheral Muscle Near-Infrared Spectroscopy in Neonates: Ready for Clinical Use? A Systematic Qualitative Review of the Literature.

BACKGROUND: Peripheral muscle near-infrared spectroscopy (NIRS) measurements are of increasing interest especially in the care of critically ill patients. OBJECTIVE: The aim was to perform a systematic qualitative review on peripheral muscle NIRS measurements in the clinical care of term and preterm neonates. METHODS: A systematic search of PubMed and Ovid Embase was performed using the following terms: neonate, neonates, newborn, newborns, infant, infants, near-infrared spectroscopy, NIRS, oxygenation, perfusion, oxygen extraction, peripheral, tissue, muscle, calf, forearm and thigh. Additional articles were identified by a manual search of the cited references. Only human studies were included. RESULTS: Twenty-one studies were identified to use peripheral muscle NIRS measurements as a single method, 17 studies combined cerebral and peripheral muscle NIRS measurements and 1 study used multi-site NIRS measurements in human neonates. Two randomized studies were identified. Two additional publications were included because they provided important general information about peripheral muscle NIRS measurements. CONCLUSION: In the care of critically ill neonates peripheral muscle NIRS measurements alone or in combination with cerebral or multi-site NIRS measurements provide useful additional information about peripheral circulation and oxygenation. This method is a promising tool in the recognition of early states of centralization (compensated shock) in this vulnerable group of patients. However, before this method can be used in the clinical routine it has to be tested as monitoring to guide interventions in further studies.

Multiparametric assessment of vascular function in peripheral artery disease: dynamic measurement of skeletal muscle perfusion, blood-oxygen-level dependent signal, and venous oxygen saturation.

BACKGROUND: Endothelial dysfunction present in patients with peripheral artery disease may be better understood by measuring the temporal dynamics of blood flow and oxygen saturation during reactive hyperemia than by conventional static measurements. METHODS AND RESULTS: Perfusion, Intravascular Venous Oxygen saturation, and T2* (PIVOT), a recently developed MRI technique, was used to measure the response to an ischemia-reperfusion paradigm in 96 patients with peripheral artery disease of varying severity and 10 healthy controls. Perfusion, venous oxygen saturation SvO2, and T2* were each quantified in the calf at 2-s temporal resolution, yielding a dynamic time course for each variable. Compared with healthy controls, patients had a blunted and delayed hyperemic response. Moreover, patients with lower ankle-brachial index had (1) a more delayed reactive hyperemia response time, manifesting as an increase in time to peak perfusion in the gastrocnemius, soleus, and peroneus muscles, and in the anterior compartment, (2) an increase in the time to peak T2* measured in the soleus muscle, and (3) a prolongation of the posterior tibial vein SvO2 washout time. Intrasession and intersession repeatability were also assessed. Results indicated that time to peak perfusion and time to peak T2* were the most reliable extracted time course metrics. CONCLUSIONS: Perfusion, dynamic SvO2, and T2* response times after induced ischemia are highly correlated with peripheral artery disease severity. Combined imaging of peripheral microvascular blood flow and dynamics of oxygen saturation with Perfusion, intravascular SvO2, and T2* may be a useful tool to investigate the pathophysiology of peripheral artery disease.

Inosculation of blood vessels allows early perfusion and vitality of bladder grafts--implications for bioengineered bladder wall.

Bioengineered bladder tissue is needed for patients with neurogenic bladder disease as well as for cancer. Current technologies in bladder tissue engineering have been hampered by an inability to efficiently initiate blood supply to the graft, ultimately leading to complications that include graft contraction, ischemia, and perforation. To date, the biological mechanisms of vascularization on transplant have not been suitably investigated for urologic tissues. To better understand the mechanisms of neovascularization on bladder wall transplant, a chimeric mouse model was generated such that angiogenesis and vasculogenesis could be independently assessed in vivo. Green fluorescence protein (GFP) transgenic mice received bone marrow transplants from ß-galactosidase (LacZ) transgenic animals and then subsequent bladder wall transplants from wild-type donor mice. Before euthanization, the aorta was infused with fluorescent microbeads (fluorospheres) to identify perfused vessels. The contributions of GFP (angiogenesis) and LacZ (vasculogenesis) to the formation of CD31-expressing blood vessels within the wild-type graft were evaluated by immunohistochemistry at different time points and locations within the graft (proximal, middle, and distal) to provide a spatiotemporal analysis of neovascularization. The GFP index, a measure of angiogenic host ingrowth, was significantly higher at proximal versus mid or distal regions in animals 2-16 weeks post-transplant. However, GFP index did not increase over time in any area. Within 7 days post-transplant, perfusion of primarily wild-type, donor blood vessels in the most distal areas of the graft was observed by intraluminal fluorospheres. In addition, chimeric host-donor (GFP-wild type) blood vessels were evident in proximal areas. The contribution of vasculogenesis to vascularization of the graft was limited, as LacZ cells were not specifically associated with the endothelial cells of blood vessels, but rather found primarily in areas of inflammation. The data suggest that angiogenesis of host blood vessels into the proximal region leads to inosculation between host and donor vessels and subsequent perfusion of the graft via pre-existing graft vessels within the first week after transplant. As such, the engineering of graft blood vessels and the promotion of inosculation might prevent graft contraction, thereby potentiating the use of bioengineered bladder tissue for transplantation.

Pelvic arterial occlusive disease affects the RhoA/Rho-kinase pathway in bladder smooth muscle.

PURPOSE: We investigated the effect of pelvic arterial occlusive disease on the RhoA/Rho-kinase pathway in a rat model of chronic bladder ischemia. MATERIALS AND METHODS: Male adult Sprague Dawley® rats at age 16 weeks were divided into arterial endothelial injury and control groups. The injury group underwent balloon endothelial injury of the bilateral iliac arteries and received a 2% cholesterol diet to induce pelvic arterial occlusive disease. The control group received a regular diet. At 8 weeks cystometrograms were performed. Bladder tissue was harvested for pharmacological studies and Western blot. RESULTS: Cystometrograms showed significantly lower bladder capacity in the arterial endothelial injury group than in controls. Organ bath studies revealed significantly decreased phasic contractions induced by carbachol in bladder strips from the injury group than from controls. In controls bladder strip tonic contractions induced by carbachol were significantly decreased compared with phasic contractions. However, no significant difference was observed between phasic and tonic contractions in the injury group. The Rho-kinase inhibitor Y-27632 produced a concentration dependent decrease in tonic contractions, which was more pronounced in the injury group. Western blot showed significantly increased RhoA and Rho-kinase ß expression in the injury group. CONCLUSIONS: Our results suggest that pelvic arterial occlusive disease can affect the RhoA/Rho-kinase pathway in the bladder. This pathway might possibly be involved in the maintenance of tonic contraction and contribute to the bladder hyperactivity caused by pelvic arterial occlusive disease.

Microcirculatory perfusion shift in the gut wall layers induced by extracorporeal circulation.

OBJECTIVE: Extracorporeal circulation (ECC) is regularly applied to maintain organ perfusion during major aortic and cardiovascular surgery. During thoracoabdominal aortic repair, ECC-driven selective visceral arterial perfusion (SVP) results in changed microcirculatory perfusion (shift from the muscularis toward the mucosal small intestinal layer) in conjunction with macrohemodynamic hypoperfusion. The underlying mechanism, however, is unclear. Therefore, the aim of this study was to assess in a porcine model whether ECC itself or the hypoperfusion induced by SVP is responsible for the mucosal/muscular shift in the small intestinal wall. METHODS: A thoracoabdominal aortic approach was performed in 15 healthy pigs divided equally into three groups: group I, control; group II, thoracic aortic cross-clamping with distal aortic perfusion; and group III, thoracic aortic cross-clamping with distal aortic perfusion and SVP. Macrocirculatory and microcirculatory blood flow was assessed by transit time ultrasound volume flow measurement and fluorescent microspheres. In addition, markers for metabolism and intestinal ischemia-reperfusion injury were determined. RESULTS: ECC with a roller pump induced a significant switch from the muscularis and mucosal layer of the small intestine, even with adequate macrocirculation (mucosal/muscular perfusion ratio: group I vs II, P = .005; group I vs III, P = .0018). Furthermore, the oxygen extraction ratio increased significantly in groups II (>30%) and III (>40%) in the beginning of the ECC compared with the control (group I vs II, P = .0037; group I vs III, P = .0062). Lactate concentrations and pH values did not differ between groups I and II; but group III demonstrated a significant shifting toward a lactate-associated acidosis (lactate: group I vs III, P = .0031; pH: group I vs III, P = .0001). CONCLUSIONS: We demonstrated a significant shifting between the small intestinal gut wall layers induced by roller pump-driven ECC. The shift occurs independently of macrohemodynamics, with a significant effect on aerobic metabolism in the gut wall. Consequently, an optimal intestinal perfusion cannot be guaranteed by a roller pump; therefore, perfusion techniques need to be optimized.

[Calcium--essential for everybody]. / Wapn--niezbedny dla kazdego.

Calcium regulates majority of metabolic processes within human organism and its optimal intake decreases risk of metabolic illnesses conditioned by diet. Deficiency of calcium results in higher body max index, increase risk of insulin resistance, diabetes type 2 and osteoporosis. Diet delivering full calcium load diminished impendency of hypertension; calcium regulates tension of smooth muscles of blood vessels, limits neurotransmitters activity and also diminish hazardous activity of sodium chloride. Anticancerogenic activity of calcium results from formation insoluble bile acids and fat acids salts, and most of all, from inhibition of intestine mucosa cells hyper proliferation. Due to presence of vitamin D3, CLA, proteins and bioactive peptides emerging from them, milk is more efficient in prophylaxis of diet conditioned illnesses than calcium supplements. Efficiency of milk and dairy products in treatment of obesity, sclerosis and hypertension has been proved by DASH diet.

Altered L-type Ca2+ channel activity contributes to exacerbated hypoperfusion and mortality in smooth muscle cell BK channel-deficient septic mice.

We determined the contribution of vascular large conductance Ca2+-activated K+ (BK) and L-type Ca2+ channel dysregulation to exaggerated mortality in cecal ligation/puncture (CLP)-induced septic BK channel ß1-subunit knockout (BK ß1-KO, smooth muscle specific) mice. CLP-induced hemodynamic changes and mortality were assessed over 7 days in wild-type (WT) and BK ß1-KO mice that were either untreated, given volume resuscitation (saline), or saline + calcium channel blocker nicardipine. Some mice were euthanized 24 h post-CLP to measure tissue injury and vascular and immune responses. CLP-induced hypotension was similar in untreated WT and BK ß1-KO mice, but BK ß1-KO mice died sooner. At 24 h post-CLP (mortality latency in BK ß1-KO mice), untreated CLP-BK ß1-KO mice showed more severe hypothermia, lower tissue perfusion, polymorphonuclear neutrophil infiltration-independent severe intestinal necrosis, and higher serum cytokine levels than CLP-WT mice. Saline resuscitation improved survival in CLP-WT but not CLP-BK ß1-KO mice. Saline + nicardipine-treated CLP-BK ß1-KO mice exhibited longer survival times, higher tissue perfusion, less intestinal injury, and lower cytokines versus untreated CLP-BK ß1-KO mice. These improvements were absent in treated CLP-WT mice, although saline + nicardipine improved blood pressure similarly in both septic mice. At 24 h post-CLP, BK and L-type Ca2+ channel functions in vitro were maintained in mesenteric arteries from WT mice. Mesenteric arteries from BK ß1-KO mice had blunted BK/enhanced L-type Ca2+ channel function. We conclude that vascular BK channel deficiency exaggerates mortality in septic BK ß1-KO mice by activating L-type Ca2+ channels leading to blood pressure-independent tissue ischemia.