Gastric HCO3--secretion in the guinea pig.
Gastric HCO3--secretion in the guinea pig.
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胃 HCO3——豚鼠的分泌物。
DOI：
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发表时间：
1978
影响因子：
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通讯作者：
G. Flemström
中科院分区：
文献类型：
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作者：
A. Garner;G. Flemström
测定麻醉豚鼠胃腔内二氧化碳分压和pH值，可同时测定总H+和HCO3-胃分泌物。HCl灌胃后CO2的释放与HCO3-的减少之间存在定量的一致性。大多数情况下，HCO3-分泌基础速率(约40mueq·h-1)小于自发的H+分泌，但组胺H2受体拮抗剂(西咪替丁20 mg·kg-1或甲硫胺35 mg·kg-1)抑制胃酸分泌后，胃净分泌输出呈碱性(HCO3-大于H+)。卡巴胆碱(1-2微克·kg-1)刺激HCO3-和H+的分泌，只有后者对组胺拮抗剂敏感。阿托品(100微克·kg~(-1))可阻断HCO3-分泌的刺激，但不影响HCO3-的基础产量。HCO3-分泌量的增加与Na+净内流的增加和H+K+的Cl-净内流的增加有关。HCO3-在胃内对H+的中和可能发生在粘膜表面，并可能保护粘膜免受腔内酸的破坏。
Measurement of gastric intraluminal PCO2 and pH in the anesthetized guinea pig enabled simultaneous determination of total H+ and HCO3- gastric secretions. There was quantitative agreement between the release of CO2 and decrease in HCO3- after intragastric instillation of HCl. The basal rate of HCO3- secretion (approximately 40 mueq-h-1) was, in most cases, smaller than spontaneous H+ secretion, but gastric net secretory output was alkaline (HCO3- greater than H+) after inhibition of acid secretion with histamine H2-receptor antagonists (cimetidine 20 mg-kg-1 or metiamide 35 mg-kg-1). Carbachol (1-2 microgram-kg-1) stimulated secretion of both HCO3- and H+; only the latter response was sensitive to the histamine antagonists. Atropin (100 microgram-kg-1) blocked stimulation of HCO3- secretion but did not affect the basal output of HCO3-. An increase in HCO3- secretion was associated with an equivalent increase in net Na+ influx and an increase in the net influx of Cl- with H+ plus K+. Intragastric neutralization of H+ by HCO3- is likely to occur at the mucosal surface and may protect the mucosa from the damaging effects of intraluminal acid.