Exercise Training Could Reduce Age-Induced Microvascular Impairment Related to Its Anti-Oxidant Potential.

Objective: During aging, an ineffective perfusion of tissues/organs is a major risk factor for several diseases. Age-induced oxidative stress has been proposed to correlate with this age-related microvascular dysfunction including angiogenesis impairment. It has been demonstrated that exercise training could ameliorate oxidative damage, as well as, enhance angiogenesis in various organs. Therefore, the present study aims to investigate whether exercise training can prevent alterations of capillary vascularity in brain and bone during aging. Design and method: Male Wistar rats were divided into three groups: sedentary-young (aged 4-6 months), sedentary-aged (aged 20-22 months) and train-aged (aged 20-22 months). The exercise program included swimming training 5 days/week for 8 weeks. We directly observed microvasculature of brain and bone by using a laser scanning confocal microscopic system. The microvascular networks were visualized by fluorescein isothiocyanate labeled dextran and were analyzed for capillary vascularity by image analysis software. Blood was collected to determine the level of malondialdehyde, an indicator of oxidative stress. Results: In sedentary-aged group, the malondialdehyde level was significantly increased, whereas capillary vascularities in brain and bone were significantly decreased when compared to the sedentary-young group (P<0.05). In train-aged group, capillary vascularities in brain and bone were significantly higher, whereas the malondialdehyde level was significantly lower when compared to the sedentary-aged group (P<0.05). Besides, the result also showed a linear correlation between capillary vascularity and malondialdehyde level. Conclusion: The exercise training could attenuate age-induced suppression of capillary vascularity in brain and bone, closely related to exercise-ameliorated oxidative stress during aging.

Effects of ACE-I on diabetic cardiovascular complications: anti-hypertensive and non-antihypertensive doses.

To evaluate the effects of angiotensin converting enzyme inhibitor (ACE-I) on diabetic cardiovascular complications, a streptozotozin (STZ, i.p., 70 mg/kg BW) induced diabetes rat model was used. The animals were separated into four major groups including: control (NSS), STZ-treated rats, STZ-treated rats received daily oral feeding of cilazapril starting one day after STZ injection (STZ-C1), and STZ-treated rats received daily oral feeding of cilazapril eight weeks after the STZ injection (STZ-C8). Within the groups of STZ-C1 and STZ-C8, the animals were also divided into three subgroups of six rats that received different doses of cilazapril treatment, 0.01 mg/Kg BW, 1 mg/Kg BW, and 10 mg/Kg BW. By using the modified isolated heart model, the parameters of mean arterial pressure (MAP), heart rate (HR), left ventricular isotonic contraction (LVIC), aortic flow rate (AFR), coronary flow rate (CFR), and ratio of heart weight per body weight (R) were assessed for each groups 8 and 20 weeks after the STZ injections. Moreover, the changes of wall thickness of the left ventricular wall (LV), right ventricular wall (RV), and interventricular septal wall (IVS) were monitored from the scanning electron micrographs of each heart. The results indicated that in both STZ-C1 and STZ-C8, the diabetic hypertension could be prevented or treated by anti-hypertensive doses of cilazaprils. Besides, the values of AFR, CFR, and LVIC were significantly increased when comparing between the STZ and STZ-C1 or STZ-C8. The results of morphological examinations indicated that: (1) left ventricular walls of the three hearts of STZ-rats had increased significantly more than controls. (2) Right ventricular walls and interventricular septal walls were not significantly different among STZ-rats, cilazapril treated STZ-rats and age matched controls. Therefore, it is concluded that ACE-I could act either as a cardioprotective or therapeutic agent for diabetic hearts. Both major anti-hypertension and anti-trophic effects of ACE-I have already been elucidated.

Therapeutic effects of Aloe vera on cutaneous microcirculation and wound healing in second degree burn model in rats.

OBJECTIVE: To demonstrate the microcirculatory and wound healing effects of Aloe vera on induced second degree burn wounds in rats. METHOD: A total of 48 male Wistar rats were equally divided into 4 groups as follows: sham controls, untreated burn-wound rats, those treated with once-daily application of normal saline (NSS) and those treated with once-daily application of lyophilized Aloe vera gel. The animals in each group were equally subdivided into 2 subgroups for the study of cutaneous microcirculation and wound healing on day 7 and 14 after burn. Dorsal skinfold chamber preparation and intravital fluorescence microscopic technique were performed to examine dermal microvascular changes, including arteriolar diameter, postcapillary venular permeability and leukocyte adhesion on postcapillary venules. RESULTS: On day 7, the vasodilation and increased postcapillary venular permeability as encountered in the untreated burn were found to be reduced significantly (p < 0.05) in both the NSS- and Aloe vera-treated groups, but to a greater extent in the latter. Leukocyte adhesion was not different among the untreated, NSS- and Aloe vera-treated groups. On day 14, vasoconstriction occurred after the wound had been left untreated. Only in the Aloe vera-treated groups, was arteriolar diameter increased up to normal condition and postcapillary venular permeability was not different from the sham controls. The amount of leukocyte adhesion was also less observed compared to the untreated and NSS- treated groups. Besides, the healing area of the Aloe vera-treated wound was better than that of the untreated and NSS- treated groups during 7 and 14 days after burn. CONCLUSION: Aloe vera could exhibit the actions of both anti-inflammation and wound healing promotion when applied on a second degree burn wound.