Nutrient arteries provide the endosteal blood supply to maintain bone remodelling and energy metabolism. Here, we investigated the distribution and function of perivascular nerves in regulating the contractility of the tibial nutrient artery. Changes in artery diameter were measured using a video tracking system, while the perivascular innervation was investigated using fluorescence immunohistochemistry. Nerve-evoked phasic constrictions of nutrient arteries were suppressed by phentolamine (1 μM), an α-adrenoceptor antagonist, guanethidine (10 μM), a blocker of sympathetic transmission, or fluoxetine (10 μM), a serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitor. In arteries pretreated with guanethidine, residual nerve-evoked constrictions were abolished by a high concentration of propranolol (10 μM) that is known to inhibit 5-HT receptors, or ketanserin (100 nM), a 5-HT receptor antagonist, but not SB207216 (1 μM), an antagonist of 5-HT and 5-HT receptors. Bath-applied 5-HT (100 nM) induced arterial constriction that was suppressed by propranolol (10 μM) or ketanserin (100 nM). Nerve-evoked arterial constrictions were enhanced by spantide (1 μM), a substance P (SP) receptor antagonist, or L-nitro arginine (L-NA; 100 μM), an inhibitor of nitric oxide synthase (NOS). Immunohistochemistry revealed 5-HT-positive nerves running along the arteries that are distinct from perivascular sympathetic or substance P-positive primary afferent nerves. For the first time, functional serotonergic nerves are identified in the tibial nutrient artery of the guinea pig. Thus, it appears that tibial nutrient arterial calibre is regulated by the balance between sympathetic and serotonergic vasoconstrictor nerves and vasodilator afferent nerves that release substance P-stimulating endothelial nitric oxide (NO) release.
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http://dx.doi.org/10.1007/s00424-020-02362-9 | DOI Listing |
Pathology
November 2024
Institutionen för kliniska vetenskaper, Lunds Universitet, Klinisk Patologi & Medicinsk Service, Region Skåne, Lund, Sweden.
Optimal blood flow through a patent cerebral circulation is critical for supply of oxygen and nutrients for brain function. The integrity of vascular elements within arterial vessels of any calibre can be compromised by various disease processes. Pathological changes in the walls of veins and the venous system may also alter the dynamics of cerebral perfusion.
View Article and Find Full Text PDFActa Neuropathol Commun
December 2024
Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany.
Severity and outcome of strokes following cerebral hypoperfusion are significantly influenced by stress responses of the blood vessels. In this context, brain endothelial cells (BEC) regulate inflammation, angiogenesis and the vascular resistance to rapidly restore perfusion. Despite the relevance of these responses for infarct volume and tissue recovery, their transcriptional control in BEC is not well characterized.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Paris Cardiovascular Research Center, Université Paris Cité, Inserm U970, Paris F-75015, France.
The integrity of the blood-retina barrier (BRB) is crucial for phototransduction and vision, by tightly restricting transport of molecules between the blood and surrounding neuronal cells. Breakdown of the BRB leads to the development of retinal diseases. Here, we show that Netrin-1/Unc5b and Norrin/Lrp5 signaling establish a zonated endothelial cell gene expression program that controls BRB integrity.
View Article and Find Full Text PDFNutrients
December 2024
Center for Magnesium Education and Research, Pahoa, HI 96778, USA.
In the past 20 years, a large number of epidemiological studies, randomized controlled trials, and meta-analyses have found an inverse relationship between magnesium intake or serum magnesium and cardiovascular disease, indicating that low magnesium status is associated with hypertension, coronary artery calcification, stroke, ischemic heart disease, atrial fibrillation, heart failure, and cardiac mortality. Controlled metabolic unit human depletion-repletion experiments found that a mild or moderate magnesium deficiency can cause physiological and metabolic changes that respond to magnesium supplementation, which indicates that these types of deficiencies or chronic latent magnesium deficiency are contributing factors to the occurrence and severity of cardiovascular disease. Mechanisms through which a mild or moderate magnesium deficiency can contribute to this risk include inflammatory stress, oxidative stress, dyslipidemia and deranged lipid metabolism, endothelial dysfunction, and dysregulation of cellular ion channels, transporters, and signaling.
View Article and Find Full Text PDFNutrients
November 2024
Research Institute for High Human Performance and Health Promotion, Khon Kaen University, Khon Kaen 40000, Thailand.
Despite the increasing importance of the condition of post-stroke cognitive impairment (PSCI), the current therapy efficacy is limited. Since oxidative stress and inflammation are targeted in anti-stroke therapy, we aimed to assess the protective effect against PSI of an orodispersible film loaded with silkworm pupae hydrolysate and a combined extract of holy basil and ginger (JP1), which show antioxidant, and anti-inflammation effects. Male Wistar rats (200-250 g) were administered JP1 at doses of 1, 10, and 100 mg/kg BW 45 min before a 6 h immobilization stress exposure for 14 days.
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