Acetazolamide on the ventral medulla of the cat increases phrenic output and delays the ventilatory response to CO2.
Acetazolamide on the ventral medulla of the cat increases phrenic output and delays the ventilatory response to CO2.
复制标题
猫腹侧延髓上的乙酰唑胺会增加膈输出并延迟对二氧化碳的通气反应。
DOI：
10.1113/jphysiol.1991.sp018760
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Nattie,EE
中科院分区：
文献类型：
--
作者：
Coates,EL;Li,AH;Nattie,EE
1.在氯醛糖-氨基甲酸乙酯麻醉、迷走神经切断、颈动脉失神经、瘫痪、伺服通风的猫延髓头端腹外侧面或延髓面下微量注射0.1 mM乙酰唑胺，可使综合膈神经活动持续增加。2.在延髓吻端腹外侧区下测得的细胞外pH在表面乙酰唑胺后显示出持续的下降，但不能很好地预测每种动物的膈神经活动的变化。3.延髓碳酸酐酶抑制使快阶跃CO_2反应的斜率减小，膈神经反应的半衰期增加。相反，乙酰唑胺不影响对稳态二氧化碳增加的膈神经反应。4.这些数据表明，髓质碳酸氢酶的局部抑制导致中枢调节的通气量增加，我们将其归因于髓组织高碳酸血症和酸中毒。此外，这些数据表明，髓质碳酸酐酶可能在中枢CO2化学转导中发挥作用。
1. Acetazolamide (0.1 mM) applied to the surface of the rostral ventrolateral medulla or microinjected beneath the medullary surface in chloralose‐urethane‐anaesthetized, vagotomized, carotid‐denervated, paralysed, servo‐ventilated cats produced a long‐lasting increase in integrated phrenic nerve activity. 2. Extracellular pH measured beneath the rostral ventrolateral medulla exhibited a long‐lasting decrease after surface acetazolamide but was not a good predictor, in each individual animal, of changes in phrenic activity. 3. Medullary carbonic anhydrase inhibition reduced the slope and the half‐time of the phrenic response to rapid step CO2 increases. Conversely, acetazolamide did not affect the phrenic response to steady‐state CO2 increases. 4. These data indicate that localized inhibition of medullary carbonic anhydrase causes a centrally mediated increase in ventilation that we attribute to medullary tissue hypercapnia and acidosis. In addition, these data indicate that medullary carbonic anhydrase may play a role in central CO2 chemotransduction.