Caldesmon, an inhibitory actin binding protein, binds to actin and inhibits actin-myosin interactions, whereas caldesmon phosphorylation reverses the inhibitory effect of caldesmon on actin-myosin interactions, potentially leading to enhanced contraction. The goal of this study was to investigate the cellular signaling pathway responsible for caldesmon phosphorylation, which is involved in the ...

In this study we characterized the effects of the protein phosphatase (PP) type 1 and type 2A inhibitor cantharidin (Cant) and its structural analogs cantharidic acid and endothall on PP activity, force of contraction, and myosin light chain phosphorylation in rat aorta. All compounds inhibited PP activity in homogenates of rat aorta with a rank order of potency of Cant = cantharidic acid > end...

Whereas previous studies suggest that tumor necrosis factor-alpha (TNF-alpha) induces cardiac contraction-relaxation deficits, the mechanisms remain unclear. Our recent studies have implicated cardiac-derived nitric oxide (NO). This study examined the detrimental and protective effects of NO donors S-nitroso-N-acetyl-penicillamine (SNAP) or (Z)-1- [N-(3-ammonio-propyl)-N-(n-propyl)amino]diazen-...

Vascular 5-Hydroxytryptamine2A (5-HT2A) receptor signaling and contraction has been associated with the activation of L-type calcium channels, phospholipase C (PLC) and, as we previously demonstrated, tyrosine kinase activation. We hypothesize the 5-HT2A receptor activates all three pathways independently to elicit contraction and that one of the tyrosine kinases activated by 5-HT is mitogen-ac...

Endothelin-1 (ET-1), a potent vasoconstrictor, has been implicated in the pathogenesis of coronary vasospasm by enhancing coronary vasoconstriction to vasoactive eicosanoids; however, the cellular mechanisms involved are unclear. We investigated whether physiological concentrations of ET-1 enhance coronary smooth muscle contraction to vasoactive eicosanoids by activating specific protein kinase...

1 Possible involvement of sympathetic purinergic transmission in the neurogenic response of dog cerebral and basilar arteries was examined with the use of alpha, beta-methylene ATP and adrenoceptor, cholinoceptor blocking agents. 2 In the isolated basilar arteries, electrical transmural stimulation produced a transient contraction which was frequently followed by a relaxation. This transient co...

jachymski [ proc. amer. math. soc., 136 (2008), 1359-1373] gave modified version of a banach fixed point theorem on a metric space endowed with a graph. in the present paper, (g, φ)-graphic contractions have been de ned by using a comparison function and studied the existence of fixed points. also, hardy-rogers g-contraction have been introduced and some fixed point theorems have been proved. s...