Spontaneous contractions of liver fluke muscle were abolished in Ca2+-free saline and by 100 μM nifedipine and reduced by 5 mM cadmium chloride, suggesting that they are dependent on extracellular Ca2+. Caffeine (5 mM) significantly increased contraction amplitude and frequency. Ryanodine (100 μM) failed to block the caffeine response but significantly reduced spontaneous contraction frequency,...

Contraction of glomerular mesangial cells is stimulated in vitro by the vasoconstrictor metabolite of arachidonic acid, thromboxane A2. To establish the role of mesangial prostaglandin (PG) synthesis in the modulation of contractile responses, we studied the effects of the stable thromboxane A2/endoperoxide analogue U-46619 on cultured rat mesangial cells preincubated with 1) four structurally ...

Interactions of hormones stimulating and inhibiting uterine contraction were studied in vitro in uteri from oophorectomized rats. The beta-adrenergic effector, isoproterenol, a potent inhibitor of contraction, produced a dose-related increase of adenylate cyclase and accumulation of adenosine 3':5'-cyclic monophosphate (cAMP) that was inhibitable by propranolol. Oxytocin, which stimulates contr...

*Correspondence: [email protected] 1Department of Mathematics, Çankaya University, Ankara, 06530, Turkey Full list of author information is available at the end of the article Abstract We prove that the Banacah contraction principle proved by Matthews in 1994 on 0-complete partial metric spaces can be extended to cyclical mappings. However, the generalized contraction principle proved by (I...

Helical strips of human coronary arteries contracted in response to histamine concentration dependently, they relaxed with low concentrations and contracted with high concentrations. Treatment with cimetidine potentiated contraction in the strips with intact and damaged endothelium to a similar extent and attenuated relaxation. Removal of endothelium abolished relaxation and potentiated contrac...

Electrically conditioned skeletal muscle can provide the continuous power source for cardiac assistance devices. Optimization of the available sustained power from in vivo skeletal muscle requires knowledge of its metabolic utilization and constraints. A thermistor-based technique has been developed to measure temperature changes and to provide a relative estimate for metabolic utilization of i...

This study was designed to investigate the effect of Aurantii fructus immaturus flavonoid (AFIF) on the contraction of isolated gastric smooth muscle in rats and explore its underlying mechanisms. Isolated antral longitudinal smooth muscle strip (ALSMS) and pyloric circular smooth muscle strip (PCSMS) of rats were suspended in tissue chambers. The responses of ALSMS and PCSMS to administration ...

PURPOSE To investigate the effects of C-type natriuretic peptide (CNP) and sodium nitroprusside (SNP) on cyclic guanosine monophosphate (cGMP) accumulation and on carbachol (CCh)-stimulated inositol 1,4,5-triphosphate (IP3) production and contraction in ciliary muscle (CM) and iris sphincter (Sph) isolated from bovine and other mammalian species. METHODS Ciliary muscle and sphincter isolated ...

OBJECTIVE Biomedical interest in brown adipose tissue (BAT) has increased since the discovery of functionally active BAT in adult humans. Although white adipose tissue (WAT) influences vascular function, vascular effects of BAT are elusive. Thus, we investigated the regulatory role and putative vasoprotective effects of BAT, focusing on hydrogen peroxide, nicotinamide adenine dinucleotide phosp...

OBJECTIVE To characterise the inotropic response of isolated myocytes to a range of structurally unrelated NO donors and to assess the role of NO release kinetics, NO species and cyclic nucleotides in mediating the observed changes. METHOD Guinea-pig (GP) and human myocytes were prepared by enzymatic digestion. Paced contractile amplitude was recorded at 37 degrees C. NO release was measured ...