Mechanisms of Modulation of Adrenergic Regulation of Spontaneous Activity Rate and Atrial Myocardial Contractility in Early Postnatal Ontogeny in Rats.

We studied combined effect of the β-adrenoreceptor agonist isoproterenol and the Y receptor agonist [Leu31, Pro34]neuropeptide Y on the frequency of spontaneous activity and myocardial contractility in 21- and 100-day-old rats. Isoproterenol increased the frequency of spontaneous activity and reduced the main parameters of isometric contraction of the atrial myocardium. When [Leu31, Pro34]neuropeptide Y was added, the frequency of spontaneous activity and the negative inotropic and the positive chronotropic effects of isoproterenol were reduced in 100-day-old rats.

Response of Isolated Rat Heart to α-Adrenergic Receptor Stimulation after I Current Blockade in the Late Postinfarction Period.

We studied the effect of α-adrenoreceptor activation after preliminary I-current blockade on the performance of the Langendorff-isolated rat heart 54 days after modeling myocardial infarction. Stimulation of α-adrenoreceptors against the background of application of I blocker ZD7288 in concentrations of 10 and 10 M decreased myocardial inotropy in isolated rat hearts by 50 and 39% (p<0.05) and increased HR by 20 and 15% (p<0.

Langendorff-Isolated Rat Heart after Acute Experimental Myocardial Infarction.

A comparative analysis of functioning of Langendorff-isolated heart from intact rats, sham-operated rats, and rats with a model of myocardial infarction one day after ligation of the left coronary artery was carried out. No significant differences in inotropic and chronotropic functions of the heart were found in the groups of intact and sham-operated animals. In the group of rats with the myocardial infarction model, an increase in HR and a decrease in the maximum contraction and relaxation rates and left-ventricular developed pressure were shown in comparison with the groups of intact and sham-operated animals.

Sediment transfer at different spatial and temporal scales in the Sichuan Hilly Basin, China: Synthesizing data from multiple approaches and preliminary interpretation in the context of climatic and anthropogenic drivers.

Quantifying sediment production and transfer at different spatial and temporal scales in a changing environment is critical in understanding the potential effects of climatic and anthropogenic drivers. Accordingly, estimates of soil erosion and sediment production at hillslope field, first-order small catchment (<0.25km) and river basin scales in the Sichuan Hilly Basin of Southwestern China, generated using a variety of techniques, including fallout radionuclide tracing, runoff plot observations, core chronology dating and conventional sediment flux monitoring, were synthesized and interpreted in the context of potential climatic and human controls.

Novel water-soluble methanofullerenes C60[C13H18O4(OH)4]6 and C60[C9H10O4(OH)4]6: Promising uncouplers of respiration and phosphorylation.

Here, we report for the first time on two novel water-soluble polyol-methanofullerenes which uncouple respiration and oxidative phosphorylation. A cytofluorimetric JC-1-based ratiometric assay was used to quantify mitochondrial potential Ψm in Yarrowia lipolytica cells exposed to the fullerenes tested. Both methanofullerenes significantly downregulated Ψm, thereby decreasing the subset of cells with high mitochondrial potential compared with intact control cells.