白足鼠每日蛰伏期间的细胞内pH值。

Intracellular pH during daily torpor in Peromyscus maniculatus.

作者信息

Nestler J R

机构信息

Department of Environmental, Population, and Organismic Biology, University of Colorado, Boulder 80309.

出版信息

J Comp Physiol B. 1990;159(6):661-6. doi: 10.1007/BF00691711.

DOI:10.1007/BF00691711

PMID:2335594

Abstract

Intracellular and extracellular acid-base parameters during normothermy and daily torpor were examined in deer mice (Peromyscus maniculatus). [14C]Dimethyloxazolidinedione and [3H]inulin were used to assess intracellular pH in liver, heart, skeletal muscle, and brain. Buffering capacities were determined using tissue homogenates. A significant increase in plasma PCO2 and CCO2 during daily torpor indicates a respiratory acidosis. All tissues experienced a reduction in the calculated dissociation ratio of histidine imidazole groups (alpha imid) during daily torpor (16.5% for brain, approximately 10% for other tissues). Based on comparisons with physicochemical tissue buffering capacities, metabolic compensation of the respiratory acidosis occurred in liver, heart, and plasma, while brain was more acidotic than predicted. The more extensive change in brain alpha imid might influence a regulated decrease in body temperature. Comparison of acid-base parameters during daily torpor and hibernation suggests that the magnitude of acid-base modifications in mammals may be associated with the level of dormancy.

摘要

在常温和每日蛰伏期间，对鹿鼠（白足鼠）的细胞内和细胞外酸碱参数进行了检测。使用[¹⁴C]二甲基恶唑烷二酮和[³H]菊粉来评估肝脏、心脏、骨骼肌和大脑中的细胞内pH值。使用组织匀浆来测定缓冲能力。每日蛰伏期间血浆PCO₂和CCO₂显著升高，表明存在呼吸性酸中毒。在每日蛰伏期间，所有组织中组氨酸咪唑基团的计算解离率（α咪唑）均降低（大脑降低16.5%，其他组织约降低10%）。基于与物理化学组织缓冲能力的比较，肝脏、心脏和血浆中发生了呼吸性酸中毒的代谢性代偿，而大脑的酸中毒程度比预期更严重。大脑α咪唑更广泛的变化可能会影响体温的调节性降低。每日蛰伏和冬眠期间酸碱参数的比较表明，哺乳动物酸碱变化的幅度可能与休眠水平有关。