Astragaloside IV Inhibits Membrane Ca[Formula: see text] Current but Enhances Sarcoplasmic Reticulum Ca[Formula: see text] Release.

Astragaloside IV (AS-IV) is one of the active ingredients in Astragalus membrananceus (Huangqi), a traditional Chinese medicine. The present study investigated the effects of AS-IV on Ca[Formula: see text] handling in cardiac myocytes to elucidate its possible mechanism in the treatment of cardiac disease. The results showed that AS-IV at 1 and 10[Formula: see text][Formula: see text]M reduced KCl-induced [Ca[Formula: see text]] increase ([Formula: see text] from 1.

Nucleotides maintain the activity of Cav1.2 channels in guinea-pig ventricular myocytes.

The activity of Cav1.2 Ca(2+) channels is maintained in the presence of calmodulin and ATP, even in cell-free patches, and thus a channel ATP-binding site has been suggested. In this study, we examined whether other nucleotides, such as GTP, UTP, CTP, ADP and AMP, could be substituted for ATP in guinea-pig ventricular myocytes.

Low-Mg(2+) treatment increases sensitivity of voltage-gated Na(+) channels to Ca(2+)/calmodulin-mediated modulation in cultured hippocampal neurons.

Culture of hippocampal neurons in low-Mg(2+) medium (low-Mg(2+) neurons) results in induction of continuous seizure activity. However, the underlying mechanism of the contribution of low Mg(2+) to hyperexcitability of neurons has not been clarified. Our data, obtained using the patch-clamp technique, show that voltage-gated Na(+) channel (VGSC) activity, which is associated with a persistent, noninactivating Na(+) current (INa,P), was modulated by calmodulin (CaM) in a concentration-dependent manner in normal and low-Mg(2+) neurons, but the channel activity was more sensitive to Ca(2+)/CaM regulation in low-Mg(2+) than normal neurons.

[High intracellular Mg²⁺ affects the activities of L-type calcium channel in guinea- pig ventricular myocytes].

This study is aimed to investigate the effects of high intracellular Mg²⁺ on L-type calcium channel in guinea-pig ventricular myocytes. The cardiomyocytes were acutely isolated with enzyme digestion method. By adopting inside-out configuration of patch clamp technique, single channel currents of the L-type calcium channel were recorded under different intracellular Mg²⁺ concentrations ([Mg²⁺]i).

Repeated oral treatment with polysaccharide sulfate reduces insulin resistance and dyslipidemia in diabetic dyslipidemic rat model.

Polysaccharide sulfate (PSS) is a new type of antiatherosclerotic medicine for its effects of anticoagulation, anti-thrombosis and modulation of dyslipidemia. However, it is still uncertain whether PSS could modulate the diabetic dyslipidemia or not. Here, the rat model of diabetic dyslipidemia was developed and the effects of PSS on glucose and lipid levels were investigated in this animal model.