AI Article Synopsis
- Retinal pericytes are essential for managing blood flow in the retina, and this study aimed to identify potassium (K+) channels in these cells and explore how their activity is influenced by beta-adrenergic stimulation.
- Isolated bovine retinal pericytes showed an inward K+ current that was dependent on extracellular potassium levels and sensitive to barium, indicating the presence of inward-rectifying K+ channels.
- Two voltage-dependent outward K+ currents, KV and BKCa, were found to be activated by physiological stimuli like increased potassium concentration and beta-adrenergic receptor stimulation, hinting at their role in regulating retinal blood flow.
Article Abstract
Retinal pericytes are key cells involved in the regulation of retinal blood flow. The purpose of this work was to identify the K+ channel population expressed in cultured bovine retinal pericytes and to determine whether beta-adrenergic stimulation alters the activity of these channels. Isolated pericytes were obtained by homogenization and filtration of bovine retina and K+ channels were studied with the whole-cell configuration of the patch-clamp technique on 3-5 passaged pericytes. Pericytes expressed an inward current dependent on extracellular K+ concentration which was sensitive to micromolar concentrations of barium, a characteristic of an inward-rectifying K+ current. Furthermore, two voltage-dependent outward currents were also observed. Their activation and inactivation properties, as well as their respective sensitivity to 4-aminopyridine and iberiotoxin, were indicative of voltage-sensitive and large-conductance calcium-activated K+ channels (BKCa). Isoproterenol and dibutyryl cyclic adenosine monophosphate enhanced the activity of BKCa without affecting the other potassium currents. In conclusion, bovine retinal pericytes express mainly two outward potassium currents, KV and BKCa, as well as an inward rectifying K+ current, Kir. Physiologic stimuli such as an increase in extracellular potassium concentration or beta-adrenergic receptor stimulation enhance the activity of Kir and BKCa, respectively, suggesting a potential role for these channels in the control of retinal blood flow.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1097/00005344-200309000-00009 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Pharmacological depletion of pericytes induces diabetic retinopathy-like abnormal blood vessels in neonatal rat retina.
Exp Eye Res
January 2025
Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan. Electronic address:
Diabetic retinopathy is a major ocular complication associated with diabetes mellitus. Pericyte loss is a hallmark of diabetic retinopathy. The platelet-derived growth factor (PDGF)-B-PDGF receptor-β (PDGFRβ) signaling pathway plays an important role in the proliferation and migration of pericytes.
View Article and Find Full Text PDFPerifoveal vascular anomalous complex and telangiectatic capillaries: An overview of two entities potentially sharing a common pathophysiology.
Surv Ophthalmol
January 2025
School of Medicine, Vita-Salute San Raffaele University, Milan, Italy; Division of head and neck, Ophthalmology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy. Electronic address:
Focal capillary ectasia in the macular region can manifest in distinct clinical scenarios, which can be categorized into 2 main entities: perifoveal vascular anomalous complex (PVAC) and telangiectatic capillaries (TelCaps). PVAC represents a primary, idiopathic condition, whereas TelCaps occur secondary to underlying vascular disorders, including diabetic macular edema and retinal vein occlusion. We provide a comprehensive analysis of these 2 entities, encompassing their clinical presentations, multimodal imaging findings, histological evidence, and differential diagnosis from other retinal microvascular abnormalities, such as Type 1 macular telangiectasia, adult-onset Coats disease, Type 3 macular neovascularization in age-related macular degeneration, and retinal arterial macroaneurysms.
View Article and Find Full Text PDFReceptor-Interacting Protein Kinase-3 Expression Impacts Ocular Vascular Development and Pathological Neovascularization.
Cells
December 2024
Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA.
Functional cell death pathways are essential for normal ocular vascular development and tissue homeostasis. As our understanding of necrosis-based cell death pathways has expanded, the inclusion of regulated forms, including necroptosis, ferroptosis, and oxytosis, has occurred. Although the existence of these pathways is well described, our understanding of their role during vascular development and pathological neovascularization is very limited.
View Article and Find Full Text PDFBiglycan stimulates retinal pathological angiogenesis via up-regulation of CXCL12 expression in pericytes.
FASEB J
January 2025
Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Article Synopsis
- Retinal pathological angiogenesis (PA) is linked to diseases like age-related macular degeneration and diabetic retinopathy, and this study explores the role of the protein biglycan (BGN) in this process using a mouse model.
- The researchers found that BGN levels increased in the retinas of mice with oxygen-induced retinopathy and that inhibiting BGN led to reduced PA, suggesting BGN plays a crucial role in promoting this condition.
- Further analysis indicated that BGN's effect on PA may involve the upregulation of another protein, CXCL12, and blocking the interaction between CXCL12 and its receptor significantly decreased PA in mice, highlighting the importance of pericytes in
Müller cells and retinal angiogenesis: critical regulators in health and disease.
Front Cell Neurosci
December 2024
Laboratorio de Neurobiología Molecular y Celular de la Glía, Facultad de Medicina, Departamento de Bioquímica, UNAM, Mexico City, Mexico.
Müller cells are the most abundant glial cells in the mammalian retina. Their morphology and metabolism enable them to be in close contact and interact biochemically and physically with almost all retinal cell types, including neurons, pericytes, endothelial cells, and other glial cells, influencing their physiology by releasing bioactive molecules. Studies indicate that Müller glial cells are the primary source of angiogenic growth factor secretion in the neuroretina.
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!