A new function for lactate in the toad Bufo marinus.
A new function for lactate in the toad Bufo marinus.
复制标题
蟾蜍中乳酸的新功能。
DOI：
10.1152/jappl.1994.76.6.2405
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Wood,SC
中科院分区：
文献类型：
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作者：
Portner,HO;Branco,LG;Malvin,GM;Wood,SC
在两栖动物蟾蜍marinus，渐进性缺氧低于临界PO 2 elyphan一个短暂的50%的增加O2的消耗，同时发生的乳酸盐的形成。本研究旨在检验乳酸盐导致代谢率升高的假设。动脉推注pH中性乳酸钠溶液（4 mmol/kg体重）在蟾蜍维持缺氧实际上引起了类似的代谢率增加。应用肾上腺素能拮抗剂（甲苯磺酸溴苄铵、酚妥拉明、普萘洛尔和利血平）可抑制这种反应，这表明与儿茶酚胺有关。此外，注射乳酸盐的动物会移动到较冷的环境（行为体温过低），这是一种在缺氧期间有益的行为反应。我们假设，根据坎农的概念，紧急反应，乳酸可能作为一个报警信号在缺氧。然而，在缺氧和常氧条件下的动物中均观察到乳酸的信号功能，因此在未来的研究中，无论何时出现乳酸水平升高，都应考虑乳酸的信号功能，例如，在运动期间和之后。
In the amphibian Bufo marinus, progressive hypoxia below a critical PO2 elicits a transient 50% increase in O2 consumption that coincides with the onset of lactate formation. The present study was designed to test the hypothesis that lactate causes the observed rise in metabolic rate. Arterial bolus infusions of pH-neutral sodium lactate solutions (4 mmol/kg body wt) in toads maintained under hypoxia actually elicit a similar increase in metabolic rate. The application of adrenergic antagonists (bretylium tosylate, phentolamine, propranolol, and reserpine) inhibits this response, suggesting that catecholamines are involved. Moreover, animals injected with lactate move to a cooler environment (behavioral hypothermia), a behavioral response that is beneficial during hypoxia. We hypothesize that, in accordance with Cannon's concept of an emergency response, lactate may function as an alarm signal during hypoxia. However, the signal function of lactate is observed in animals both under hypoxia and under normoxia and should thus be considered in future studies whenever elevated lactate levels are present, e.g., during and after exercise.