Acute and chronic effects of carotid body denervation on ventilation and chemoreflexes in three rat strains
Acute and chronic effects of carotid body denervation on ventilation and chemoreflexes in three rat strains
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DOI：
10.1113/jphysiol.2012.234658
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发表时间：
2012-07-01
影响因子：
5.5
通讯作者：
Hodges, Matthew R.
中科院分区：
文献类型：
--
作者：
Mouradian, Gary C., Jr.;Forster, Hubert V.;Hodges, Matthew R.
棕色挪威（BN）大鼠在CO2敏感性方面存在相对特定的缺陷。这种缺陷可能是由于异常弱的颈动脉体对CO2敏感性的贡献。因此，我们测试了这样的假设，即与其他大鼠品系相比，CBD对BN大鼠的正常呼吸和CO2敏感性的影响较小。在BN、Sprague-Dawley（SD）和Dahl盐敏感（SS）大鼠中，我们测量了在双侧或假CBD之前和之后23天的静息（正常呼吸）和缺氧（F-IO 2 =0.12）或高碳酸血症（F-ICO 2 =0.07）期间的通气量和血气。在所有三个品系的大鼠中，CBD在CBD后1-2天引起了正常呼吸低通气（Δ P-aCO_2 + 8.7 - 11.0 mmHg）（P < 0.05），并且减弱了对缺氧（P < 0.05）和静脉氰化钠（NaCN; P < 0.05）的缓解反应，而假CBD对静息呼吸、血气和化学反射没有影响（P > 0.05）。相反，CBD对所有菌株的CO2敏感性（Δ（V）过点（E）/Δ（aCO 2））没有影响（P > 0.05）。正常呼吸的P-aCO 2在CBD后15-23天内恢复到CBD前的值。因此，CBD在大鼠中的作用（1）进一步支持颈动脉体在正常血气调节中的重要作用，（2）表明颈动脉体不是大鼠CO2敏感性的主要决定因素，（3）可能不支持大鼠外周和中枢化学感受器之间相互作用的概念。
Brown Norway (BN) rats have a relatively specific deficit in CO2 sensitivity. This deficit could be due to an abnormally weak carotid body contribution to CO2 sensitivity. Accordingly, we tested the hypothesis that CBD would have less of an effect on eupnoeic breathing and CO2 sensitivity in the BN rats compared to other rat strains. We measured ventilation and blood gases at rest (eupnoea) and during hypoxia (F-IO2=0.12) or hypercapnia (F-ICO2=0.07) before and up to 23 days after bilateral or Sham CBD in BN, SpragueDawley (SD) and Dahl Salt-Sensitive (SS) rats. In all three rat strains, CBD elicited eupnoeic hypoventilation (Delta P-aCO2 +8.7-11.0 mmHg) 1-2 days post-CBD (P < 0.05), and attenuated ventilatory responses to hypoxia (P < 0.05) and venous sodium cyanide (NaCN; P < 0.05), while sham CBD had no effect on resting breathing, blood gases or chemoreflexes (P > 0.05). In contrast, CBD had no effect on CO2 sensitivity (Delta(V)over-dot(E)/Delta(aCO2)) in all strains (P > 0.05). Eupnoeic P-aCO2 returned to pre-CBD values within 15-23 days post-CBD. Thus, the effects of CBD in rats (1) further support an important role for the carotid bodies in eupnoeic blood gas regulation, (2) suggest that the carotid bodies are not a major determinant of CO2 sensitivity in rats, and (3) may not support the concept of an interaction among the peripheral and central chemoreceptors in rats.