Hallbäck M, Jones J V, Bianchi G, Folkow B
Acta Physiol Scand. 1977 Feb;99(2):208-16. doi: 10.1111/j.1748-1716.1977.tb10371.x.
The cardiovascular responses to acute mental "stress" were compared in the Milan strain of spontaneously hypertensive rats (MHS) and in normotensive control rats (NR). Blood pressure and heart rate were followed in pairs of awake MHS and NR, while defence reactions were provoked by alerting stimuli (noise, vibration). No differences were noted between the two groups in response to "stress" although resting heart rate in MHS was lower than in NR. Administration of atropine or propranolol to MHS and NR showed the MHS to have a higher resting vagal tone and lower sympathetic tone than the NR. Subsequent (at least two weeks later) hemodynamic investigation, under nembutal anesthesia, showed no difference in cardiac output between MHS and NR but a higher stroke volume, presumably related to the lower heart rate in MHS. Thus, total peripheral resistance was increased in MHS as was the ratio left ventricular weight/body weight, and in good proportion to the blood pressure rise. Thus MHS differ substantially in both their responses to "stress" and also hemodynamically from the Okamoto strain of spontaneously hypertensive rat (SHR), being the so far most studied and best known model of essential hypertension in man. In MHS the hypertension is more of a systolic type and is of primarily renal origin. As such, MHS provide another model for investigating the polygenic nature of hypertension in man.
在米兰品系的自发性高血压大鼠（MHS）和正常血压对照大鼠（NR）中比较了对急性精神“应激”的心血管反应。对成对的清醒MHS和NR监测血压和心率，同时通过警报刺激（噪音、振动）引发防御反应。尽管MHS的静息心率低于NR，但两组对“应激”的反应未发现差异。对MHS和NR给予阿托品或普萘洛尔后发现，MHS的静息迷走神经张力高于NR，而交感神经张力低于NR。随后（至少两周后）在戊巴比妥麻醉下进行的血流动力学研究表明，MHS和NR之间的心输出量没有差异，但MHS的每搏输出量较高，这可能与MHS较低的心率有关。因此，MHS的总外周阻力增加，左心室重量/体重比也增加，且与血压升高成良好比例。因此，MHS在对“应激”的反应以及血流动力学方面与冈本品系的自发性高血压大鼠（SHR）有很大不同，SHR是迄今为止人类原发性高血压研究最多、最著名的模型。在MHS中，高血压更多是收缩型的，主要起源于肾脏。因此，MHS为研究人类高血压的多基因性质提供了另一个模型。
