Rioux F, Lemieux M, Lebel M
Centre de Recherche, Hôtel-Dieu de Québec, Canada.
Peptides. 1990 Sep-Oct;11(5):921-6. doi: 10.1016/0196-9781(90)90010-3.
The reflex changes of systemic blood pressure (BP) and heart rate (HR) induced by intraperitoneal (IP) injections of neurotensin-containing solutions (NTCS) were measured in anesthetized guinea pigs whose BP was raised up by intravenous (IV) infusions of either angiotensin II (ATII) or noradrenaline (NA), and compared to those observed in control animals (i.e., saline-infused guinea pigs with low initial BP level). The amplitudes of reflex pressor and tachycardic responses to IP NTCS were either not affected or reduced in animals whose BP was raised with ATII or NA. However, no hypotensive effect was observed, following IP NTCS, in any of the animals tested. The results indicate that high initial BP levels tend to attenuate the reflex increases of BP and HR caused by IP NTCS, the level of inhibition being largely determined by the type of vasopressor agent utilized to raise up the BP. They also suggest that the initial BP level is unlikely to be an important factor in determining whether the activation of capsaicin-sensitive visceral afferents will produce hypotensive or hypertensive effects in this animal model.
在通过静脉输注血管紧张素II（ATII）或去甲肾上腺素（NA）使血压升高的麻醉豚鼠中，测量腹腔注射含神经降压素溶液（NTCS）引起的全身血压（BP）和心率（HR）的反射性变化，并与对照动物（即初始血压水平低的生理盐水输注豚鼠）中观察到的变化进行比较。在通过ATII或NA使血压升高的动物中，对腹腔NTCS的反射性升压和心动过速反应幅度要么未受影响，要么降低。然而，在任何受试动物中，腹腔注射NTCS后均未观察到降压作用。结果表明，初始血压水平较高往往会减弱腹腔NTCS引起的血压和心率反射性升高，抑制程度在很大程度上取决于用于升高血压的升压药类型。它们还表明，在该动物模型中，初始血压水平不太可能是决定辣椒素敏感内脏传入神经激活会产生降压还是升压作用的重要因素。
