ABSTRACT
Reducing glycemic excursion is of great importance to the successful practice for diabetes intervention and complication prevention. This is also an advantage of traditional Chinese medicine (TCM) in the treatment of diabetes. More and more studies have shown that the dysfunction of islet microcirculation is the key pathological link for glycemic excursion caused by decrease of islet function. The over-activation of local renin-angiotensin system (RAS) in islet microcirculation is a key ring to the islet decompensation, intimately related to the functionality of islet endocrine cells, and has gradually become the focus in the study of islet functionality. In TCM, it is believed that glycemic excursion in diabetes mellitus is closely related to the incapability of "spleen Qi to dispersing essence". If spleen fails to disperse essence, the essence will be accumulated in the body and become harmful stuffs. The stuffs further break the blood glucose homeostasis, acting as the key pathogenesis of diabetes. By supplementing the "spleen" Qi and promoting the dispersion of nutrient substance (hormone) in "pancreas", the balance between sugar-regulated hormones can be restored and therefore glycemic excursion can be reduced. However, the regulation mechanism of "spleen Qi to dispersing essence" on glycemic excursion remains unclear at present. Based on the previous clinical and scientific work, the following ideas were proposed by the authors:the effects of "spleen Qi to dispersing essence" on the improvement of islet function and the regulation of glycemic excursion may be achieved by promoting islet microcirculation, and its mechanism may be related to inhibiting the activation status of local RAS in islet microcirculation. It is important to note that the mutual antagonistic relationship between the signal pathways of RAS in islet microcirculation is similar to the antagonistic relationship between "spleen Qi to dispersing essence" and spermatozoa in TCM. Thus, the mechanism of "spleen Qi to dispersing essence" on the regulation mechanism of blood glucose fluctuations needs to be further explored from the perspective of the overall regulation of RAS in islet microcirculation, so as to reveal the scientific connotation of TCM on regulating the body's environmental homeostasis and reducing glycemic excursion in diabetic patients.
ABSTRACT
<p><b>OBJECTIVE</b>The aim of the present study was to study the Effects of 11,12-epoxyeicosatrienoic acid (11,12-EET) on cardioplegia and reperfusion arrhythmias in the isolated perfused immature rabbit hearts.</p><p><b>METHODS</b>Isolated immature rabbit hearts were randomly divided into two groups: group 1 (St. Thomas No.2 solution control n = 8) and group 2 (St. Thomas No.2 solution plus 11,12-EET n = 8). By means of Langendorff technique, these isolated rabbit hearts underwent (15 degrees C) hypothermia, 2 hours of ischemia after infusion of cardioplegic solution and 1 hour of reperfusion (37 degrees C). The mean times until the cessation of both electrical and mechanical activity were measured after infusion of cardioplegia. The same index until occurrence of both electrical and mechanical activity after reperfusion was observed too. We also measured the arrhythmias score, heart rate, coronary blood flow during the reperfusion and the myocardial water content, myocardial calcium content at the endpoint of the reperfusion period.</p><p><b>RESULTS</b>The times until electrical [(9.3 +/- 0.9) s vs (13.6 +/- 1.9) s, P < 0.01] and mechanical [(4.5 +/- 1.7) vs (7.3 +/- 2.1) s, P < 0.05] activity arrest were significantly shorter in the group 2 than those in the control group. 11,12-EET also provided significantly better myocardial water content [(84 +/- 4)% vs (90 +/- 5)%, P < 0.01], arrhythmia scores (2.03 +/- 0.83 vs 3.88 +/- 1.25, P < 0.01), coronary blood flow and myocardial calcium content [(3.22 +/- 0.33) micro mol/gram dry weight (gdw) vs (3.97 +/- 0.26) micro mol/gdw, P < 0.01] compared with control. There were no significant changes with heart rate and the mean times until occurrence of both electrical and mechanical activity after reperfusion.</p><p><b>CONCLUSIONS</b>These data suggest that 11,12-EET added to the cardioplegic solution of St. Thomas No.2 has better cardioplegia effects and lower incidence of reperfusion arrhythmias.</p>