Neuronostatin attenuates myocardial contractile function through inhibition of sarcoplasmic reticulum Ca2+-ATPase in murine heart.

Background/aims: Neuronostatin, derived from the somatostatin preprohormone, was recently identified to be produced by several tissues exerting a role in cardiovascular regulation and metabolism. Nonetheless, the precise mechanism behind neuronostatin-elicited myocardial responses remains elusive.

Methods: This study was designed to elucidate the impact of neuronostatin on cardiac contractile function and the underlying mechanism of action involved.

Expression patterns of atrial natriuretic peptide and its receptors within the cochlear spiral ganglion of the postnatal rat.

The spiral ganglion, which is primarily composed of spiral ganglion neurons and satellite glial cells, transmits auditory information from sensory hair cells to the central nervous system. Atrial natriuretic peptide (ANP), acting through specific receptors, is a regulatory peptide required for a variety of cardiac, neuronal and glial functions. Although previous studies have provided direct evidence for the presence of ANP and its functional receptors (NPR-A and NPR-C) in the inner ear, their presence within the cochlear spiral ganglion and their regulatory roles during auditory neurotransmission and development is not known.

Cardiac peroxisome proliferator-activated receptor-γ expression is modulated by oxidative stress in acutely infrasound-exposed cardiomyocytes.

The aim of the present study was to examine the effects of acute infrasound exposure on oxidative damage and investigate the underlying mechanisms in rat cardiomyocytes. Neonatal rat cardiomyocytes were cultured and exposed to infrasound for several days. In the study, the expression of CAT, GPx, SOD1, and SOD2 and their activities in rat cardiomyocytes in infrasound exposure groups were significantly decreased compared to those in the various time controls, along with significantly higher levels of O2 (-) and H2O2.

Expression and localization of atrial natriuretic peptide and its receptors in rat spiral ganglion neurons.

Spiral ganglion neurons (SGNs) are the primary auditory neurons in the inner ear, conveying auditory information between sensory hair cells and the central nervous system. Atrial natriuretic peptide (ANP), acting through specific receptors, is a regulatory peptide required for a variety of cardiac and neuronal functions. While the localization of ANP and its receptors (NPR-A and NPR-C) in the inner ear has been widely studied, there is only limited information regarding their localization in cochlear SGNs and their regulatory roles during primary auditory neurotransmission.

Infrasound exposure induces apoptosis of rat cardiac myocytes by regulating the expression of apoptosis-related proteins.

It has been reported that exposure to infrasound causes cardiac dysfunction. Allowing for the key role of apoptosis in the pathogenesis of cardiovascular diseases, the objective of this study was to investigate the apoptotic effects of infrasound. Cardiac myocytes cultured from neonatal rats were exposed to infrasound of 5 Hz at 130 dB.

AC-NP: a novel chimeric peptide with natriuretic and vasorelaxing actions.

The aim of this study was to evaluate the cardiovascular and renal activities of a newly designed natriuretic peptide (NP). Here, we engineered a novel 28-amino acid chimeric peptide, termed AC-NP that combined the 17-amino acid ring of C type natriuretic peptide (CNP) with the 6-amino acid N-terminus and 5-amino acid C-terminus of atrial natriuretic peptide (ANP). Both in vitro and in vivo experiments were performed to determine the actions of AC-NP.

Protecting effects of vasonatrin peptide against carbon tetrachloride-induced liver fibrosis.

In order to investigate the effects of vasonatrin peptide (VNP), a novel man-made natriuretic peptide, on liver fibrosis, mice received carbon tetrachloride (CCl(4)) injection for 12weeks and with or without VNP treatment during the last 6weeks. Hematoxylin-eosin (HE) staining and Sirius red staining were performed to evaluate the status of liver fibrosis. After treatment of VNP, DNA and collagen synthesis of cultured HSC-T6 hepatic stellate cells were assessed by [(3)H]-thymidine and [(3)H]-proline incorporation, respectively.

Protective effects of vasonatrin peptide against hypobaric hypoxia-induced pulmonary hypertension in rats.

1. The aim of the present study was to investigate the in vivo effects of vasonatrin peptide (VNP) on hypoxia-induced pulmonary hypertension (HPH). 2.

Suppressive effects of swainsonine on C6 glioma cell in vitro and in vivo.

Swainsonine, an extract from Astragalus membranaceus, is known for its anti-cancer effects and could prevent metastases. In order to investigate the effects and mechanisms of swainsonine in C6 glioma cells, we carry out correlated experiments in vitro and in vivo. After treatment with swainsonine, the effective dose and IC(50) value of swainsonine in the C6 glioma cell were examined using the MTT assay.

[Inhibitory effects of rosiglitazone against endothelin-1-induced proliferation of rat cardiac myocytes: the role of PKC-c-fos pathway].

Objective: To investigate the mechanism of rosiglitazone (RSG, the activator of peroxisome proliferators activated receptor lambda) for inhibiting endothelin-1 (ET-1)-induced neonatal rat cardiac myocyte hypertrophy and the role of protein kinase C (PKC) and c-fos.

Methods: In vitro cultured neonatal rat cardiac myocytes were treated with ET-1, phorbol ester (PMA, the PKC activator), ET-1+RSG, ET-1+chelerythrine (che, the PKC inhibitor), PMA+RSG, or without treatment (control), respectively. The effects of RSG on the protein content, (3)H-leucine incorporation, PKC activity and C-fos protein expression were observed in the cardiac myocytes stimulated with ET-1 or PMA.

Angiogenic effects of the extracts from Chinese herbs: Angelica and Chuanxiong.

Angelica and ChuanXiong are used to cure ischemic heart disease in China. Previous studies found that these two herbs could increase myocardial blood flow, oxygen-supply and keep myocardial oxygen balance, etc. However, the mechanisms of angiogenic effects of these two herbs are not well-known.

[The study on angiogenesis activity of danggui, chuanxiong and danshen].

Objective: To observe the effect of danggui (Radix angelicae sinensis), chuanxiong (Rhizoma chuanxiong) and danshen (Radix salvae miltionrrhizae) on cardiac microvascular endothelial cells (CMECs) obtained from rat and quantitation of vessels on chick embryo chorioallantoic membrane (CAM) model.

Methods: Normal rat cardiac microvascular endothelial cells (CMECs) were cultured by collagenase and trypsin and the influences of the herbs on the CMECs were observed by cell count and MTT colorimetry. The activity of blood vessels was determined by quantitation of vessels on chick embryo chorioallantoic membrane (CAM) model.

[Effect of vasonatrin peptide on the Ca2+ activated K+ channels of vascular smooth muscle cells isolated from rat mesentery arteries].

Aim: To investigate effect and mechanism of vasonatrin peptide (VNP) on Ca2+ activated K+ channels (K(Ca)) of vascular smooth muscle cells (VSMCs) isolated from rat mesentery arteries.

Methods: Changes of K(Ca) induced by VNP were measured by the means of whole cell recording mode of patch clamp, furthermore effects of HS-142-1(0.3 g/L), 8-Br-cGMP and methylene blue (MB) were observed.

Inhibition of hypoxia-induced proliferation and collagen synthesis by vasonatrin peptide in cultured rat pulmonary artery smooth muscle cells.

The aim of the present research is to investigate the effects of vasonatrin peptide (VNP) on hypoxia-induced proliferation and collagen synthesis in pulmonary artery smooth muscle cells (PASMCs). Smooth muscle cells isolated from rat pulmonary artery were cultured and used at passages 3-5. Cell proliferation and collagen synthesis were evaluated by cell counts, [(3)H] thymidine and [(3)H] proline incorporation.

[Vasonatrin peptide attenuates the enhancement of electrically-induced intracellular calcium transient by isoproterenol in rat cardiac myocytes].

The purpose of this study was to investigate the effects of vasonatrin peptide (VNP) on electrically-induced intracellular calcium ([Ca(2+)](i)) transient and mechanism of the effects in the cardiac myocytes. The [Ca(2+)](i) transient was measured with a fluoremetric method. The effects of HS-142-1, 8-Br-cGMP and methylene blue (MB) on [Ca(2+)](i) transient in cardiac myocytes were also determined.

Down-regulation of C-type natriuretic peptide receptor by vasonatrin peptide in cardiac myocytes and fibroblasts.

Aim: To investigate the regulatory effects of vasonatrin peptide (VNP) on the expression of C-type natriuretic peptide receptor (NPR-C) in cultured neonatal rat cardiac myocytes and fibroblasts.

Methods: Quantitative RT-PCR was undertaken to evaluate the levels of NPR-C mRNA and radioimmunoassay was used to determine the formation of intracellular cGMP.

Results: Twenty-four hours hypoxic exposure increased the level of NPR-C mRNA in cardiomyocytes, while did not alter the expression of NPR-C in cardiac fibroblasts.

[Effect of bradykinin on the sodium channel current in dorsal root ganglion neuron].

Aim: To investigate the effects of bradykinin on voltage-dependent sodium channel currents in rat dorsal root ganglion neurons (DRG).

Methods: Whole-cell patch clamp technique was used to determine sodium channel current.

Results: Bradykinin at 0.

[Vasorelaxing role of vasonatrin peptide in human intramammary artery in vitro].

The purpose of this study was to investigate the vasorelaxing effect of vasonatrin peptide (VNP) on human intramammary artery (HIMA).The vasorelaxing effect of VNP on HIMA was measured by means of perfusion in vitro. The effects of HS-142-1, TEA, 8-Br-cGMP and methylene blue (MB) were also observed.

[Progress in research on heat shock proteins in cardiovascular system].

Diverse physiological stresses (e.g., heat shock, ischemia and hemodynamics) produce multiple changes in a cell that affect metabolic processes and cellular structures.

[Study on the mechanism of how vasonatrin peptide can attenuate the growth-promoting effect of hypoxia in cardiac fibroblasts].

Aim: To investigate how vasonatrin peptide (VNP) can attenuate the growth-promoting effect of hypoxia in cardiac fibroblasts cultured from neonatal rats.

Methods: The cultured cardiac fibroblasts were divided randomly into four groups: control group, hypoxia group, hypoxia + VNP group and hypoxia + 8-Bromo-cGMP group. The growth of cardiac myocytes was measured by the means of MTT method.

[Effect of vasonatrin peptide on the expression of C-type natriuretic peptide receptor in hypoxic rat hearts].

Aim: To investigate the effect of vasonatrin peptide (VNP) on the expression of C-type natriuretic peptide receptor (NPR-C) in hypoxic rat hearts.

Methods: Rats were divided randomly into three groups: control group, hypoxia group(3-28 d) and VNP (25-75 microg/kg per day) + hypoxia group. The plasma concentration of atrial natriuretic peptide (ANP) in rats was measured by the means of radioimmunoassay.

[Inhibition of moderate hypoxia-induced protein synthesis by vasonatrin peptide in cultured neonatal rat cardiomyocytes].

The present work was to investigate the effects of vasonatrin peptide (VNP) on cardiomyocyte protein synthesis induced by moderate hypoxia. In cultured neonatal rat cardiomyocytes, MTT methods, total protein measurement and (3)H-leucine incorporation were used to calculate the cell number and measure the protein synthesis of cardiomyocytes. Furthermore, radioimmunoassay was undertaken to observe the effects of VNP on the intracellular levels of cAMP, cGMP and the concentration of endothelin (ET) in the culture medium.