Activation of transient receptor potential vanilloid 1 inhibits RhoA/Rho kinase and improves vasorelaxation dysfunction mediated by high-fat diet in mice / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the role of dietary capsaicin in activating transient receptor potential vanilloid 1 (TRPV1) and thus influencing the vascular dysfunction mediated by high-fat diet and the potential mechanisms.</p><p><b>METHODS</b>A total of 80 male C57BL/6J mice aged 10 weeks were equally divided into four groups, in which the mice were fed with normal diet (ND), normal diet plus capsaicin (NC), high-fat diet (HD), or high-fat diet plus capsaicin (HC) for 20 weeks. Tail-cuff blood pressure (BP), vascular function of mice aortic rings, expressions of voltage-gated potassium-channel Kv1.4, RhoA and Rho kinase in aorta were examined.</p><p><b>RESULTS</b>Compared with ND group, both nitroglycerin [(18.9 +/- 13)% vs. 100%, P < 0.01] and acetylcholine [(26 +/- 12)% vs. 100%, P < 0.01] induced vasorelaxation of aortic rings were significantly reduced in HD group. Both endothelium dependent and independent aortic rings vasorelaxation in HC group were significantly improved compared with that in HD group [acetylcholine: (69 +/- 15)%; nitroglycerin: (46.5 +/- 6)%, P < 0.05], but still reduced compared with that in ND group (P < 0.05, P < 0.01). High fat diet induced the expression of RhoA and Rho kinase. Dietary capsaicin down-regulated the expression of RhoA and Rho kinase but up-regulated the expression of Kv1.4 in aorta in mice fed with normal or high fat diet (all P < 0.05).</p><p><b>CONCLUSION</b>Dietary capsaicin can ameliorate vasorelaxation dysfunction mediated by high-fat diet. The potential mechanisms may be related with TRPV1 activation, which in turn stimulates potassium channel and inhibits RhoA and Rho kinase in the vasculature.</p>

Relationship between abdominal obesity and left ventricular weight/function / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the relationship between abdominal obesity and left ventricular weight/function.</p><p><b>METHODS</b>A total of 495 patients [265 males, mean age (55 +/- 12) years] with hypertension (139), diabetes (65), metabolic syndrome (285), diabetes complicated with hypertension (11) were enrolled in this study. Visceral adipose area (VA), the subcutaneous adipose (SA), the total abdominal adipose (TA) were measured by computerized tomography (CT) and left ventricular weight and function were obtained by echocardiography. Patients were divided into three groups according to the VA (I. VA<75 cm(2), n=173, II. VA>75 and < 110 cm(2), n=153, III. VA >or= 110 cm(2), n=169).</p><p><b>RESULTS</b>Left ventricular mass (LVM) and LVM index (LVMI) increased and LVEF and E/A decreased in proportion to increasing VA. Left ventricular hypertrophy (LVH) rate was significantly higher in group II and III compared to group I and LVEF was significantly reduced in group III compared to group I and II. There are significant correlation between LVMI and VA, SA, TA as well as between LVEF and VA after adjusting gender, age and blood pressure. Logistic regression analysis showed that VA is an independent predictor for LVH.</p><p><b>CONCLUSION</b>The abdominal adipose accumulation is closely related to the left ventricular weight and function.</p>

Renin-angiotensin system in mesenteric adipose tissues in rats with metabolic syndrome / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the renin-angiotensin system (RAS) in mesenteric adipose tissues and effect of angiotensin II on adipocyte differentiation.</p><p><b>METHODS</b>Thirty normal 8-week-old male Wistar rats were divided into groups on normal diet and high-fat diet. The rats on high-fat diet for 24 weeks developed the metabolic syndrome respectively. The mRNA and protein expression of mesenteric adipose tissue were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Lipid drop in 3T3-L1 preadipocytes and mature adipocytes were observed using oil-red O staining. The fluorescence microscope was used to detect cytosolic-free calcium in 3T3-L1 preadipocytes and mature adipocytes.</p><p><b>RESULTS</b>The expressions of angiotensinogen, angiotensin converting enzyme, angiotensin II receptor type 1 in mesenteric adipose tissue were significantly increased in rats with metabolic syndrome compared with those in rats on normal diet (P <0. 05, P <0. 01). After administration of angiotensin II , no lipid droplet in 3T3 -L1 preadipocytes and adipocytes were observed, however, intensive lipid droplet in adipocyte was found after administration of captopril and candesartan. Angiotensin II increased the intracellular-free calcium concentration in preadipocytes (P < 0. 01 ) , which was blocked by captopril and candesartan; in contrast, angiotensin II effect was blunt in mature adipocyte. Captopril and candesartan partially recovered the angiotensin II -mediated increase of cytosolic-free calcium.</p><p><b>CONCLUSION</b>RAS in the mesenteric adipose tissues is active in rats with metabolic syndrome, and antagonization of RAS can recover the lipogenesis of adipocyte.</p>

Study on the relationship between insulin resistance and type 2 diabetes mellitus with postural hypotension / 第三军医大学学报

Objective　To investigate the occurrence of postural hypotension (PH) in patients suffering from type 2 diabetes mellitus with or without hypertension (DMH or DM), and the relationship of PH and diabetic neuropathy, hyperinsulinemia and insulin resistance. Methods　A total of 30 cases of type 2 DM and 30 cases of DMH were included in this study. The blood pressure of all subjects were measured in supine and standing body positions respectively and PH was defined as a decline from supine to standing was ≥20 mmHg in systolic blood pressures (SBP). The concentrations of blood glucose and plasma insulin were measured to calculate the insulin sensitive index (ISI). Autonomic and peripheral function was determined by measuring the postural heart rates and the conduction speeds of superficial peroneal and communicating branch of peroneal nerves etc respectively. Results　Significant difference (P<0.01) was found in the occurrence of PH in the patients with DM (40%) and those with DMH (67%). The changes of postural blood pressure were more obvious in those with DM+PH and DMH+PH than in those with simple DM (P<0.01). The conduction speeds of newes were significantly lower in those with DMH+PH than with simple DM (P<0.05), but the occurrence of autonomic neuropathy had no difference between the 2 groups. There was no difference in postural heart rate, body mass index and blood glucose levels in fasting and 2 h after meal among the DM, DM+PH and DMH+PH groups. The concentrations of plasma insulin of those with DMH+PH were significantly higher, but their ISI significantly lower than those of the patients with DM respectively (P<0.01). The decline of postural SBP in patients with DMH+PH had a significantly positive correlation with their plasma insulin levels in fasting condition (r=0.689, P<0.01). Conclusion　The patients with DMH are more prone to PH compared with those only with DM and PH damages their peripheral nerves. Most of diabetic patients with PH suffer from obvious IR and hyperinsulinemia, and if with hypertension, the above metabolic disturbances are more severe.

Study on the relationship between insulin resistance and type 2 diabetes mellitus with postural hypotension / 第三军医大学学报

Objective　To investigate the occurrence of postural hypotension (PH) in patients suffering from type 2 diabetes mellitus with or without hypertension (DMH or DM), and the relationship of PH and diabetic neuropathy, hyperinsulinemia and insulin resistance. Methods　A total of 30 cases of type 2 DM and 30 cases of DMH were included in this study. The blood pressure of all subjects were measured in supine and standing body positions respectively and PH was defined as a decline from supine to standing was ≥20 mmHg in systolic blood pressures (SBP). The concentrations of blood glucose and plasma insulin were measured to calculate the insulin sensitive index (ISI). Autonomic and peripheral function was determined by measuring the postural heart rates and the conduction speeds of superficial peroneal and communicating branch of peroneal nerves etc respectively. Results　Significant difference (P<0.01) was found in the occurrence of PH in the patients with DM (40%) and those with DMH (67%). The changes of postural blood pressure were more obvious in those with DM+PH and DMH+PH than in those with simple DM (P<0.01). The conduction speeds of newes were significantly lower in those with DMH+PH than with simple DM (P<0.05), but the occurrence of autonomic neuropathy had no difference between the 2 groups. There was no difference in postural heart rate, body mass index and blood glucose levels in fasting and 2 h after meal among the DM, DM+PH and DMH+PH groups. The concentrations of plasma insulin of those with DMH+PH were significantly higher, but their ISI significantly lower than those of the patients with DM respectively (P<0.01). The decline of postural SBP in patients with DMH+PH had a significantly positive correlation with their plasma insulin levels in fasting condition (r=0.689, P<0.01). Conclusion　The patients with DMH are more prone to PH compared with those only with DM and PH damages their peripheral nerves. Most of diabetic patients with PH suffer from obvious IR and hyperinsulinemia, and if with hypertension, the above metabolic disturbances are more severe.