El Agaty S M T, Seif A A
Physiology Department, Faculty of Medicine, Ain Shams University, 74 Abbassiya Street, Abdou Pasha Square, Cairo, Egypt,
Ir J Med Sci. 2015 Jun;184(2):265-72. doi: 10.1007/s11845-014-1098-z. Epub 2014 Mar 18.
To evaluate the possible beneficial effect of long-term caffeine administration on cardiovascular system in aged rats.
This study was carried out on 20 senile male albino rats, aged 18-20 months. Rats were divided into caffeine-treated group, which received 25 mg/kg caffeine by gavage daily for 6 weeks, and control group. All rats were subjected to the following in vivo measurements: body weight, arterial blood pressure, heart rate and ECG recording. In vitro measurements included studying isolated hearts in a Langendorff apparatus for their intrinsic properties as well as plasma levels of lipids, malondialdehyde and nitrate.
Caffeine administration to aged rats significantly enhanced the baseline and maximum values achieved in response to isoproterenol infusion in isolated heart preparation for both maximum rate of tension development (dT/dt max) and time to peak tension (TPT). The responses of hearts isolated from caffeine group to the three doses of isoproterenol infusion also showed a significantly higher dT/dt max with shorter TPT and half relaxation time (1/2 RT) compared to controls. Plasma nitrate was significantly increased and ECG recording was nonsignificantly affected in caffeine group. The plasma levels of total cholesterol, LDL cholesterol as well as in vivo heart rate and systolic, diastolic and mean arterial blood pressures were all significantly increased associated with a significant decrease in HDL cholesterol in caffeine group.
Long-term caffeine administration in aged rats increased cardiac inotropy, lusitropy and preserved NO level, which points to a promising potential favorable effect on cardiac intrinsic properties.
评估长期给予咖啡因对老年大鼠心血管系统可能产生的有益作用。
本研究以20只18 - 20月龄的雄性老年白化大鼠为对象。将大鼠分为咖啡因处理组，该组大鼠每日经口灌胃给予25 mg/kg咖啡因，持续6周，以及对照组。所有大鼠均接受以下体内测量：体重、动脉血压、心率和心电图记录。体外测量包括在Langendorff装置中研究离体心脏的固有特性以及血浆脂质、丙二醛和硝酸盐水平。
给予老年大鼠咖啡因显著提高了离体心脏标本在异丙肾上腺素输注时达到的基线值和最大值，无论是最大张力发展速率（dT/dt max）还是达到峰值张力的时间（TPT）。与对照组相比，从咖啡因组分离的心脏对三种剂量异丙肾上腺素输注的反应也显示出显著更高的dT/dt max，TPT和半舒张时间（1/2 RT）更短。咖啡因组血浆硝酸盐显著升高，心电图记录无显著影响。咖啡因组总胆固醇、低密度脂蛋白胆固醇的血浆水平以及体内心率和收缩压、舒张压及平均动脉血压均显著升高，同时高密度脂蛋白胆固醇显著降低。
长期给予老年大鼠咖啡因可增加心肌收缩力、舒张性并维持一氧化氮水平，这表明对心脏固有特性具有潜在的有利作用。
