Effects of a very-low-calorie diet and physical-training regimens on body composition and resting metabolic rate in obese females

Sixty-nine obese females received 90 d of a liquid diet providing 2184 kJ/d in clinical trials. Groups were diet only (C), diet plus endurance exercise (EE), diet plus weight training (WT), or diet plus endurance exercise and weight training (EEWT). Changes in body weight, percent fat, fat weight, and fat-free mass were not different between groups. Declines in resting metabolic rate (RMR) were approximately 7% to approximately 12% of baseline values with no differences among groups. A significant increase in work capacity (approximately 16%) was shown for EEWT. Strength index showed declines of approximately 6% for C and EE and gains of approximately 3% and approximately 10% for EEWT and WT, respectively. These clinical trials did not show advantages of any exercise regimen over diet alone for weight loss, body-composition changes, or declines in RMR. Improvements in work capacity were limited and strength improved in groups that participated in strength training.     

Endothelial and smooth muscle properties of coronary and mesenteric resistance arteries in spontaneously hypertensive rats compared to WKY rats

Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D₁₀₀) were determined and vessels were set up to a normalized internal diameter (0.9 D₁₀₀). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells.     

麦冬类中药组织切片计算机三维重建图鉴

利用计算机技术实现麦冬类中药组织连续切片三维重建与动态显示,为计算机辅助生药学鉴定和教学提供了新的三维图像技术和研究资料。     

表小檗碱对α受体的作用

表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择     

Clinical studies with the potassium channel activator cromakalim in normotensive and hypertensive subjects.

Eight normotensive subjects received single and multiple doses of cromakalim (1 mg) and placebo in a randomised double-blind cross-over study to examine general tolerance to cromakalim and its effects on blood pressure (BP), heart rate (HR), and pressor responses to norepinephrine (NE) and angiotensin II (AII). In a second study, 10 hypertensive patients whose BP control was unsatisfactory with atenolol 50-100 mg received additional treatment with placebo followed by cromakalim 1 mg daily for 4 weeks. Assessments were made of BP, HR, apparent hepatic blood flow and renal blood flow (RBF), pulmonary function, and the pharmacokinetics of atenolol. Cromakalim was generally well tolerated in both normotensive and hypertensive subjects. In the normotensive group, cromakalim produced a reflex increase in HR without any detectable decrease in BP: average (placebo-subtracted) increases in HR at 4 h were 16 beats/min with subjects in an erect position after the single dose and 14 beats/min after 7 days. Cromakalim had no effect on pressor responses to NE and AII. Addition of cromakalim to atenolol was associated with modest further reductions in BP between 0.5 and 3 h after drug administration, with maximal reductions of 21/14 mm Hg (subjects in supine position) 2 h after the first dose. Cromakalim had no effect on apparent liver blood flow and RBF, pulmonary function, and the steady-state pharmacokinetics of atenolol. Single and multiple 1-mg doses of cromakalim are well tolerated but are associated with only modest vasodilator activity.