Contractility In Group Research Articles

Erythropoietin restores bowel damage and hypoperistalsis in gastroschisis

Background and Purpose Despite the decreased mortality in gastroschisis (Gx), patients experience postoperative intestinal hypoperistalsis, malabsorption, and shortened bowel length. The trophic effects of recombinant human erythropoietin (rEpo) in the developing small bowel have been reported, increasing the length and height of the villi, and villous surface area. This study investigated the effects of rEpo on intestinal malfunction in the chick embryos with Gx. Methods Thirteen-day-old fertilized chicken eggs were used to create Gx model. Study groups included the following: group 1, control; group 2, Gx-only; group 3, Gx + 0.075% saline exchange; group 4, Gx + 10 IU rEpo exchange; group 5, Gx + 20 IU rEpo exchange. The bowels were evaluated by in vitro muscle strip technique, and the response was expressed as a percentage of the maximum carbachol-evoked contraction ( E max). In addition, parasympathetic ganglion cells per 10 plexuses and villi height were determined by light microscopy. Results were evaluated statistically by Mann-Whitney U, χ 2, and Fisher's Exact test tests. Results Saline exchange had no effect on ganglion cell number ( P = .63) and villi height ( P = .10). In group 4, ganglion cell number was not increased ( P = .82), but villi height increase was significant ( P = .03). In Gx + 20 IU rEpo group, both the number of ganglia ( P = .0001) and villi height ( P = .002) were significantly increased. The decrease in contractility in group 2 ( P = .0121) was significantly reversed by rEpo 20 IU treatment ( P = .0216), no significant difference was obtained in groups 3 ( P = .0809) and 4 ( P = .1516) compared with group 2. Conclusion These data suggest that rEpo has prokinetic effects on hypoperistalsis and restores bowel damage in Gx.

Beneficial effect of concomitant administration of isoflurane and nicorandil

In common with halogenated anaesthetics, nicorandil, a new KATP channel opener, has been shown to have cardioprotective and vasodilator effects. Recent studies have also suggested that the vasodilator and protective effects of halogenated anaesthetics are mediated partly via KATP channel opening. This study examined the effects of concurrent administration of nicorandil and isoflurane on haemodynamic state and ventricular function before, during and after 15 min of ischaemia. We studied left ventricular function in 40 anaesthetized rabbits using ultrasonomicrometry. Measurements were obtained before, during and after 15 min of regional ischaemia. Regional ventricular function was assessed in terms of systolic shortening (SS%) and preload recruitable work area (PRWA, the area beneath the regional stroke work vs end-diastolic length relationship) during reperfusion. Four groups were studied: group F (n = 10) received a bolus dose of fentanyl 100 micrograms kg-1 and then 400 micrograms kg-1 h-1 throughout; group 1 (n = 10) received 2.05% end-tidal concentration of isoflurane (1 MAC); group FN (n = 10) received fentanyl, a bolus does of nicorandil 100 micrograms kg-1 and then 25 micrograms kg-1 min-1, 15 min before occlusion; and group IN (n = 10) received isoflurane and nicorandil. Isoflurane decreased left ventricular systolic pressure and ventricular contractility (+dP/dtmax, slope of preload recruitable stroke work, and SS%). Nicorandil increased -dP/dtmax in group FN. Post-ischaemic regional left ventricular contractility in group I did not differ from that in group F, however, groups receiving nicorandil recovered to a greater extent. Group IN showed better recovery compared with all other groups when ventricular contractility was assessed by PRWA normalized to pre-occlusion values (mean 99.3 (SEM 10.5)% vs 73.4 (7.5)%, 50.2 (5.8)% and 52.4 (3.7)% at 120 min reperfusion in groups FN, I and F, respectively). Tissue ATP and lactate contents did not differ between groups. We conclude that concurrent administration of nicorandil and isoflurane enhanced post-ischaemic recovery compared with isoflurane anaesthesia or nicorandil and fentanyl administration.

Effect of lignocaine in myocardial contusion: an experiment on rabbit isolated heart.

1. The reported incidence of myocardial contusion after blunt chest trauma varies from 16 to 76%. Of these patients, about 6% present a severe, life threatening contusion. We used an isolated heart preparation to examine the effect of lignocaine on myocardial performance after contusion. 2. Thirty hearts obtained from male New Zealand rabbits were perfused at constant flow according to the Langendorff technique and were divided into four groups. The following parameters were measured at frequent intervals for 60 min: mean coronary perfusion pressure (CPP), left ventricular diastolic pressure (LVDP), developed pressure (DP), dP/dtmax, dP/dtmin. 3. Group 1 (n = 6) served as control, group 2 (n = 7) received lignocaine for 20 min (15 microM for the first 10 min and 30 microM for the following 10 min), group 3 (n = 9) had a contusion leading to a 30-50% decrease in dP/dtmax and group 4 (n = 8) had the contusion and the lignocaine infusion was started 10 min after the contusion and stopped after 30 min. Lignocaine concentration was measured in the effluent. 4. Lignocaine alone moderately decreased contractility in group 2. In group 3, after contusion, DP, dP/ dtmax, and dP/dtmin were markedly decreased during the 60 min recording period. In group 4, lignocaine infusion rapidly restored contractility. DP, dP/dtmax and dP/dtmin returned towards their basal values. This improvement of contractility remained stable, even after lignocaine infusion was discontinued. 5. In our rabbit isolated heart preparation, lignocaine at a low therapeutic concentration was able to restore contractility after contusion. These results need to be confirmed by other studies but this may lead to promising therapeutic intervention.

Effects of Diltiazem on the Functional Recovery of the Myocardium at Organ and Cellular Level During Prolonged Hypothermic Ischemic Cardiac Arrest

The effectiveness of diltiazem on the functional recovery of the heart, calcium (Ca++) uptake and binding, Ca++ ATPase of cardiac sarcoplasmic reticulum (SR), and MB fraction of creatine kinase (MBCK) of coronary sinus blood was investigated after one and a half hours of reperfusion following three hours of ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegia; and group III, cold crystalloid cardioplegia with diltiazem. There was a decrease in aortic pressures left ventricular pressure development (dp/dt), left ventricular work index (LVWI), total systemic vascular resistance (TSVR), and left ventricular systolic pressure (LVSP) in the sham bypass group. There was a decrease in cardiac index (CI), LVWI, and mean right atrial pressure (mRAP) and an increase in TSVR and pulmonary vascular resistance (PVR) in group II as compared with group I. Although there was a tendency for a decrease in the indices of myocardial contractility in group II, they were not significantly different from those in group I. The indices of myocardial contractility, CI, and LVWI in group III were slightly higher than in group II, but they were not significantly different from each other. The values for calcium uptake by SR in groups II and III were similar but significantly lower than those in group I. Calcium binding in group III was significantly lower than that in group I. Calcium ATPase of SR in the three groups were similar. Although MBCK increased in all the groups, the increases were not significantly different among the three groups. The results of this study indicate that cold crystalloid cardioplegia with diltiazem was not better than cold crystalloid alone in preserving the cardiac contractility and cellular function during prolonged ischemic cardiac arrest. However, the cardiac function in terms of cardiac index was better preserved with diltiazem.

Glucose metabolism and insulin activity during cardiac surgery

Disorders of glucose metabolism were investigated in 177 patients undergoing cardiac surgery. In group I patients, the cardiopulmonary bypass (CPB) priming fluid contained glucose. Patients in group II received neither glucose nor insulin during the operation. Group III received insulin-glucose therapy OGT) during the operation (insulin, 1 U/kg/h, glucose, 0.5 g/kg/h). At the onset of CPB in group I, hyperglycemia was produced by the glucose load and by a relative reduction in insulin secretion. In group 11, the start of the operation was accompanied by a rise in the titer of insulin antibodies. IGT resulted in normalization of the blood glucose level after CPB and stability of the insulin antibody titer during the investigation. The indices of myocardial contractility in group III were better than those of the “glucose free” group II before and after CPB. In group II, indices of β-cell function were moderately depressed 16 to 18 hours after the operation. Insulin and c-peptide level measurements demonstrated insulin production in group III on the first postoperative day. The results demonstrate that IGT has some potential benefit for glucose metabolism and myocardial function during cardiac surgery.