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Biomedical subjects

E R Trimble

Publications and source records attributed to E R Trimble.

115 records · Page 7Linked to original sources
PubMed1975

Maturity onset diabetes mellitus: response to intensive dietary management.

Analysis of the first six months of intensive dietary management of 57 maturity onset diabetics showed that a large proportion of such patients could be satisfactorily controlled without the need of either oral hypoglycaemic agents or insulin. A dietitian's assessment of the patient's adherence to the prescribed diet allowed groups of good and poor dieters to be selected. Among the poor dieters the plasma insulin and triglyceride levels were significantly increased though plasma glucose levels were not significantly higher. Dietary adherence may thus be an prognostic risk factor in this group of diabetic patients.

Adult↗
PubMedDate not supplied

Mechanical effects of ET-1 in cardiomyocytes isolated from normal and heart-failed rabbits.

Endothelin (ET-1) is found at elevated concentrations in the plasma of patients with heart failure and in animal models of cardiomyopathy. The peptide is a potent positive inotropic agent, the effects of which are mediated by increases in cytosolic Ca2+ in cardiomyocytes. The object of this study was to investigate at the cellular level, the actions of ET-1 on contractile function and on Ca2+ currents in heart-failed ventricular myocardium. Male New Zealand White rabbits (8 wks) were treated with twice weekly injections of epirubicin (4 mg/kg/wk, n = 7) or with saline (n = 7) for 6 wks, followed by a washout period of 2 wks. Ventricular cardiomyocytes were isolated from rabbit hearts using Langendorff perfusion with collagenase; contractile function was examined using a video microscopy method, and L-type Ca2+ currents were recorded using a whole-cell patch-clamp technique. ET-1 produced a concentration-dependent increase in contractile response (% increase from basal value) to a maximum at 1 nM ET-1 of 69 +/- 11% (mean +/- S.D.) in control cardiomyocytes and 33 +/- 6% in heart-failed cells. However, there was no significant change in the EC50 obtained with ET-1 for healthy (0.31 +/- 0.1 nM) and for failed cardiomyocytes (0.24 +/- 0.1 nM). The effects of ET-1 on L-type Ca2+ channels were similar with a peak amplitude at 1 nM ET-1 of -3.26 +/- 0.8 nA in control cardiomyocytes and -3.32 +/- 0.9 nA in heart-failed cells. The attenuation of the contractile response to ET-1 in heart-failed cells may reflect a desensitization of ET receptors as a consequence of elevated circulating levels of ET and was not reflected by alteration of transmembrane Ca2+ conductance. It is probable, therefore, that multiple signalling pathways are involved in the actions of ET on ventricular myocardium.

Animals↗
PubMedDate not supplied

Lack of gastric inhibitory polypeptide (GIP) response to vagal stimulation in the rat.

The effect of sham feeding on the plasma concentration of gastric inhibitory polypeptide (GIP) was studied in unrestrained rats bearing chronic gastric fistulas and jugular catheters. While no increase of plasma GIP concentration could be detected during sham feeding (fistula open), during normal feeding (fistula closed), plasma GIP concentrations rose rapidly. In contrast to GIP, plasma insulin concentrations showed a rapid and phasic response during sham feeding in the absence of changes of glycemia. In anesthetized rats electrical stimulation of the vagus nerve was without any effect on plasma GIP concentration, while plasma insulin increased rapidly by as much as 150 percent. It is concluded that under the conditions used, the full gastric and/or intestinal phases of food ingestion are necessary to trigger GIP release, and that vagal activation alone is unable to stimulate GIP release in the rat.

Adaptation, Psychological↗