Dendroaspis natriuretic peptide (DNP), a newly-described natriuretic peptide, relaxes gastrointestinal smooth muscle. L-type calcium channel currents play an important role in regulating smooth muscle contraction. The effect of DNP on L-type calcium channel currents in gastrointestinal tract is still unclear. This study was designed to investigate the effect of DNP on barium current (I(Ba)) through the L-type calcium channel in gastric antral myocytes of guinea pigs and cGMP-pathway mechanism. The whole-cell patch-clamp technique was used to record L-type calcium channel currents. The content of cGMP in guinea pig gastric antral smooth muscle and perfusion solution was measured using radioimmunoassay. DNP markedly enhanced cGMP levels in gastric antral smooth muscle tissue and in perfusion medium. DNP concentration-dependently inhibited I(Ba) in freshly isolated guinea pig gastric antral circular smooth muscle cells (SMCs) of guinea pigs. DNP-induced inhibition of I(Ba) was partially blocked by LY83583, an inhibitor of guanylate cyclase. KT5823, a cGMP-dependent protein kinase (PKG) inhibitor, almost completely blocked DNP-induced inhibition of I(Ba). However, DNP-induced inhibition of I(Ba) was potentiated by zaprinast, an inhibitor of cGMP-sensitive phosphodiesterase. Taken together, DNP inhibits L-type calcium channel currents via pGC-cGMP-PKG-dependent signal pathway in gastric antral myocytes of guinea pigs.
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http://dx.doi.org/10.1016/j.regpep.2010.05.015 | DOI Listing |
Elife
December 2024
Experimental Otology Group, InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, Göttingen, Germany.
To encode continuous sound stimuli, the inner hair cell (IHC) ribbon synapses utilize calcium-binding proteins (CaBPs), which reduce the inactivation of their Ca1.3 calcium channels. Mutations in the gene underlie non-syndromic autosomal recessive hearing loss DFNB93.
View Article and Find Full Text PDFCureus
November 2024
Department of Integrative Physiology, Akita University Graduate School of Medicine, Akita, JPN.
The global incidence of mortality due to heart failure (HF) is on the rise, presenting a significant challenge in various regions, including Japan. There is an urgent need for innovative prevention and treatment strategies to address this issue. Traditional medicine, particularly Japanese Kampo medicine (JKM), has been proposed as a potential therapeutic approach and has undergone examination in clinical trials related to HF.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
Immunology Department of Hebei Medical University, Shijiazhuang, PR China. Electronic address:
Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), result from pulmonary edema and alveolar-capillary barrier disruption due to inflammation, often triggered by conditions like sepsis. Sepsis-induced ALI (SALI) involves extensive damage to vascular endothelium and alveolar epithelium, leading to respiratory failure. Our study explores ferroptosis, an iron-dependent cell death pathway, and calcium dysregulation in SALI.
View Article and Find Full Text PDFCell Calcium
December 2024
Cardiac Signaling Center of USC, MUSC and Clemson University, 68 President St BEB 306, Charleston, SC 29425, USA. Electronic address:
Rationale & Methods: While signaling of cardiac SR by surface membrane proteins (I & I) is well studied, the regulation of mitochondrial Ca by plasmalemmal proteins remains less explored. Here we have examined the signaling of mitochondria and SR by surface-membrane calcium-transporting proteins, using genetically engineered targeted fluorescent probes, mito-GCamP6 and R-CEPIA1er.
Results: In voltage-clamped and TIRF-imaged cardiomyocytes, low Na induced SR Ca release was suppressed by short pre-exposures to ∼100 nM FCCP, suggesting mitochondrial Ca contribution to low Na triggered SR Carelease.
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