The aim of this study was to compare the effects of an angiotensin-converting enzyme (ACE) inhibitor and an angiotensin II receptor (AT) antagonist on insulin resistance, especially on muscle fiber composition in fructose-induced insulin-resistant and hypertensive rats. Six-week-old male SpragueDawley rats were fed either normal rat chow (control) or a fructose-rich diet (FFR). For the last two weeks of a six-week period of either diet, the rats were treated with gum arabic solution as a vehicle (control or FFR), angiotensin-converting enzyme inhibitor (FFR؉ACE), temocapril (1 mg/kg/ day) or an angiotensin II receptor antagonist (FFR؉AT), CS-866 (0.3 mg/kg/day), by gavage, and then the euglycemic hyperinsulinemic glucose clamp technique was performed to evaluate insulin sensitivity. At the end of the glucose clamp, the soleus muscle was dissected for determination of the muscle fiber composition by ATPase methods. Blood pressure at the glucose clamp in the FFR group was significantly higher than that of the control group, and both temocapril and CS-866 significantly lowered the blood pressure of the FFR group. The average rate of glucose infusion during the glucose clamp, as a measure of insulin sensitivity (M value), was significantly lower in the FFR rats compared to the controls (15.4 ؎ 0.4, 10.9 ؎ 0.6 mg/kg/min, for control and FFR, respectively, P < .01). Both temocapril and CS-866 partially improved the M values compared to FFR (13.2 ؎ 0.7, 12.8 ؎ 0.5 mg/kg/min, for FFR؉ACE, FFR؉AT, respectively, P < .01 compared with FFR, P < .05 compared with control). The composite ratio of type I fibers of the soleus muscle was decreased significantly in the FFR rats compared with the controls (82% ؎ 2%, 75% ؎ 2%, for control and FFR, respectively, P < .01), and both temocapril and CS-866 restored a composite ratio of type I fibers to the same level as that of the controls (81% ؎ 1%, 80% ؎ 1% for FFR؉ACE and FFR؉AT, respectively). The M value was significantly correlated with the composition of type I and type II fibers. These results suggest that the fiber composition of skeletal muscle is correlated to insulin resistance, and that both ACE inhibitors and AT antagonists may modulate the muscle fiber composition in a hypertensive and insulin-resistant animal model, fructose-fed rats, to the same extent. Am J Hypertens 2000;13:290 -297

Recovered workers in the workplace tended to show the depressive HRV feature that is the dominant sympathetic activity compared with the healthy workers. They might still be showing job stress that was not detected by the checklist. HRV analyses by APG in addition to questionnaire has the potential to become an effective approach for assessing workers' job stress to prevent repeated absences.

The aim of this study was to examine the roles of muscle fiber composition, capillary density and muscle blood flow in insulin resistance (IR) and the effect of cilnidipine, a calcium channel blocker in fructose-fed rats (FFR). Six-week-old male Sprague-Dawley rats were fed either normal rat chow or fructose-rich chow for 6 weeks. For the last 2 weeks, the rats were treated by gavage with a vehicle (Control and FFR groups) or with cilnidipine (FFR+Cil group). Blood pressure (BP) and insulin sensitivity were assessed in the sixth week. Muscle fiber composition, capillary density and blood flow in the soleus muscle were evaluated. BP of FFR was significantly higher than that of the controls. Cilnidipine significantly lowered BP in FFR. Insulin sensitivity was significantly lower in FFR than in the controls. Cilnidipine significantly improved IR in FFR. The composite ratio of type I fibers in the soleus muscle was significantly lower in FFR than in the controls, but that of type II fibers was significantly higher in FFR. Treatment with cilnidipine resulted in recovery of this ratio to that of the controls. Insulin sensitivity was found to be significantly correlated with the composite ratio of either type I fibers or type II fibers. There were no intergroup differences in capillary density. Muscle blood flow in the FFR+Cil group was higher than that in the Control or FFR groups. These results suggest that muscle fiber composition is linked to IR and that cilnidipine may improve IR in FFR either by modulating muscle fiber composition or by increasing muscle blood flow.

It is commonly known that autonomic modulations are caused by depression, fatal arrhythmia, and vascular disease. This may lead to be an urgent need of a reliable physiological technology to evaluate autonomic modulations. The specific purpose of the current study is to examine the possibility of whether the Acceleration Plethysmography (APG) system can become a new useful tool to measure autonomic modulations. We verified the heart rate variability (HRV) analysis by APG whether it can be used as same as by the ECG. The HRV is interpreted from the a-a interval (Taa) on APG waves. We assembled the simultaneous measurement system of APG and ECG, examined the identities of the R-R interval (TRR) of ECG and the Taa of APG in six subjects of 22-60 old, and then compared variables in frequency domains of HRV by both APG and ECG. The results showed a close correspondence of the Taa and the TRR . Furthermore, when the regression formula was set as Taa=C*TRR, the coefficient of regression (C) was 1.0002, 1.0001, 0.9997, 1.0000, 0.9999, 1.0001 respectively; whereas for each subject, the coefficient of determination was 0.9901, 0.9892, 0.9968, 0.9740, 0.9676, 0.9677 respectively (p<0.01). As for the difference between APG and ECG, the coefficient of variation of HRV was merely 0.1-0.2%, and the LFIHF ratio as 0.1-0.4. If we carefully interpret the results of the frequency analysis, the APG system can be a useful objective methodology to evaluate autonomic modulations. Because of its simplicity in usage, it is expected to be employed in the occupational health or primary care.

The ultrastructure of lymphatic valves was studied in rabbits and mice. The lymphatic valves usually consist of two cusps but three or four are sometimes present. The cusps are covered by endothelium. Along the free edge of the cusps are endothelial cells which can differentiate morphologically from other endothelial cells. They are named "tip-cells"; they have pseudopodlike projections and abundant cytoplasmic filaments 60-90 A in diameter. Vesicles occur in endothelial cells of both lymphatic vessels and their valves; they are on the luminal or connective tissue side and are never provided with a diaphragm like that frequently observed in blood vessels. Joining endothelial cells are zonulae occludentes but desmosomes are not observed. No open intercellular junctions are encountered along the valvular endothelium. A basement membrane (basal lamina) is more frequently observed in valves than in walls of lymphatic vessels. Connective tissue in the cusps consists of collagenous fibrils, fine filaments and fibroblasts.