Objective: To investigate the distribution and mechanism of coronary arteriole (CA) cell resting membrane potential (RP) in guinea pigs.
Methods: Cell RP was recorded by intracellular microelectrode in isolated guinea pig coronary arteriole (diameter < 100 microm).
Results: (1) Experiments were carried out in 112 cells with a mean RP of (-65 +/- 4.2)mV, the distribution of coronary arteriole cell RP fitted by Gaussian function was bimodal, one peak was -43 mV termed high RP, the other was -74 mV termed low RP. 10 mmol/L K+ and 3 micromol/ L acetylcholine(ACh) induced hyperpolarization in high-RP cells with (-7.4 +/- 0.87) mV (n = 13) and (-15 +/- 1.24) mV (n = 16) respectively, and induced depolarization in low-RP cells with (9.6 +/- 1.2) mV (n = 23) and (8.7 +/- 0.69) mV (n = 15) respectively. (2) The inward rectifier K+ channel (K(ir)) blocker Ba2+ caused concentration-dependent depolarization in low-RP cells with an EC50 of 120 micromol/L 100 micromol/L Ba2+ or higher could shift low-RP cells to high-RP state, the response of these cells to high K+ and ACh became a hyperpolarization.
Conclusion: The distribution of coronary vascular cell RP is bimodal, high K+ and ACh induce different responses in low and high RP cells. The two RP states are exchangeable mainly due to all-or-none conductance changes of K(ir).
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Increased Oxidative and Nitrative Stress and Decreased Sex Steroid Relaxation in a Vitamin D-Deficient Hyperandrogenic Rodent Model-And a Validation of the Polycystic Ovary Syndrome Model.
Nutrients
January 2025
Department of Obstetrics and Gynaecology, Semmelweis University, Üllői Street 78/a, 1082 Budapest, Hungary.
Background/objectives: Both hyperandrogenism (HA) and vitamin D deficiency (VDD) can separately lead to impaired vascular reactivity and ovulatory dysfunction in fertile females. The aim was to examine the early interactions of these states in a rat model of PCOS.
Methods: Four-week-old adolescent female rats were divided into four groups: vitamin D (VD)-supplemented ( = 12); VD-supplemented and testosterone-treated ( = 12); VDD- ( = 11) and VDD-and-testosterone-treated ( = 11).
Interventions by Cardiovascular Drugs Against Aircraft Noise-Induced Cardiovascular Oxidative Stress and Damage.
Antioxidants (Basel)
January 2025
Laboratory of Molecular Cardiology, Department of Cardiology 1, University Medical Center of the Johannes Gutenberg-University, 55131 Mainz, Germany.
Noise pollution is a known health risk factor and evidence for cardiovascular diseases associated with traffic noise is growing. At least 20% of the European Union's population lives in noise-polluted areas with exposure levels exceeding the recommended limits of the World Health Organization, which is considered unhealthy by the European Environment Agency. This results in the annual loss of 1.
View Article and Find Full Text PDFSpecialized pericyte subtypes in the pulmonary capillaries.
EMBO J
January 2025
Division of Pulmonary Medicine, Boston Children's Hospital, Boston, MA, 02115, USA.
Pericytes are essential for capillary stability and homeostasis, with impaired pericyte function linked to diseases like pulmonary arterial hypertension. Investigating pericyte biology has been challenging due to the lack of specific markers, making it difficult to distinguish pericytes from other stromal cells. Using bioinformatic analysis and RNAscope, we identified Higd1b as a unique gene marker for pericytes and subsequently generated a knock-in mouse line, Higd1b-CreERT2, that accurately labels pericytes in the lung and heart.
View Article and Find Full Text PDFCombining In Vivo Two-Photon and Laser Speckle Microscopy With the Ex Vivo Capillary-Parenchymal Arteriole Preparation as a Novel Approach to Study Neurovascular Coupling.
Microcirculation
January 2025
Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance NHS Foundation Trust, University of Manchester, Manchester, UK.
Objective: Cerebral blood flow (CBF) decline is increasingly recognized as an area of importance for targeting neurodegenerative disorders, yet full understanding of the mechanisms that underlie CBF changes are lacking. Animal models are crucial for expanding our knowledge as methods for studying global CBF and neurovascular coupling in humans are limited and require expensive specialized scanners.
Methods: Use of appropriate animal models can increase our understanding of cerebrovascular function, so we have combined chronic cranial windows with in vivo two-photon and laser speckle microscopy and ex vivo capillary-parenchymal arteriole (CaPA) preparations.
Systemic and Cardiac Microvascular Dysfunction in Hypertension.
Int J Mol Sci
December 2024
Dipartimento di Biotecnologie e Scienze della Vita, ASST Sette Laghi, Università degli Studi dell'Insubria, 21100 Varese, Italy.
Hypertension exerts a profound impact on the microcirculation, causing both structural and functional alterations that contribute to systemic and organ-specific vascular damage. The microcirculation, comprising arterioles, capillaries, and venules with diameters smaller than 20 μm, plays a fundamental role in oxygen delivery, nutrient exchange, and maintaining tissue homeostasis. In the context of hypertension, microvascular remodeling and rarefaction result in reduced vessel density and elasticity, increasing vascular resistance and driving end-organ damage.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!