Quinton P M
Division of Biomedical Sciences, University of California, Riverside 92521-0121.
FASEB J. 1990 Jul;4(10):2709-17. doi: 10.1096/fasebj.4.10.2197151.
Cystic fibrosis (CF) is a fatal genetic disease caused by abnormalities in fluid and electrolyte transport in exocrine epithelia. Both absorptive and secretory processes are affected by an underlying membrane defect in Cl- permeability. However, the impact of the defect on transport function is tissue specific. Net electrolyte absorption is decreased in the sweat duct, increased in airway epithelia, and not affected in intestine. The defect is expressed in secretion as a consistent failure in most, if not all, exocrine tissues, to beta-adrenergically stimulated and cAMP mediated secretory response. However, the secretory response to cholinergic and Ca2(+)-mediated stimulation is normal in the sweat gland, apparently normal in the airway, but absent in the intestine. The basic defect is not fatal in and of itself, and the imbalance between absorption and secretory functions may be of some selective advantage to heterozygotes in surviving complications of intestinal infections. The inherent defect in transport is probably the primary physiological cause of the ultimately fatal secondary infections in the lungs of CF homozygotes.
囊性纤维化（CF）是一种致命的遗传性疾病，由外分泌上皮中液体和电解质转运异常引起。吸收和分泌过程均受氯离子通透性潜在膜缺陷的影响。然而，该缺陷对转运功能的影响具有组织特异性。汗腺中净电解质吸收减少，气道上皮中增加，而肠道不受影响。在分泌方面，该缺陷表现为在大多数（如果不是全部）外分泌组织中，对β-肾上腺素能刺激和cAMP介导的分泌反应持续失败。然而，汗腺对胆碱能和Ca2+介导刺激的分泌反应正常，气道中显然正常，但在肠道中不存在。基本缺陷本身并不致命，吸收和分泌功能之间的失衡可能对杂合子在肠道感染并发症中存活具有一定的选择优势。转运的内在缺陷可能是CF纯合子肺部最终致命的继发感染的主要生理原因。
