Souvannakitti Dangjai, Kumar Ganesh K, Fox Aaron, Prabhakar Nanduri R
The Center for Systems Biology, Departments of Medicine, The University of Chicago, Chicago, IL 60637, USA.
Adv Exp Med Biol. 2009;648:345-9. doi: 10.1007/978-90-481-2259-2_39.
In the present study we examined the effects of intermittent (IH) and sustained hypoxia (SH) on low PO(2)-evoked catecholamine (CA) secretion from neonatal rat chromaffin cells. Experiments were performed on chromaffin cells isolated from rat pups exposed to either IH (P0-P5; 15 s hypoxia-5 min normoxia;8 h/day) or SH (hypobaric hypoxia; 0.4ATM). CA secretion from chromaffin cells was monitored by amperometry. Control chromaffin cells, from P5 rat pups, exhibited robust CA secretion in response to acute hypoxia. IH facilitated whereas SH attenuated hypoxia-evoked CA secretion. IH increased the epinephrine and norepinephrine content of the adrenal medulla whereas SH had no effect. These results demonstrate that neonatal exposures IH and SH exert diametrically opposed effects on acute hypoxia-evoked CA secretion from chromaffin cells and CA contents.
在本研究中，我们检测了间歇性低氧（IH）和持续性低氧（SH）对新生大鼠嗜铬细胞低氧分压诱发的儿茶酚胺（CA）分泌的影响。实验在从暴露于IH（出生后0至5天；15秒低氧-5分钟常氧；每天8小时）或SH（低压低氧；0.4个大气压）的幼鼠中分离出的嗜铬细胞上进行。通过安培法监测嗜铬细胞的CA分泌。来自出生后5天大鼠幼崽的对照嗜铬细胞在急性低氧刺激下表现出强烈的CA分泌。IH促进而SH减弱低氧诱发的CA分泌。IH增加了肾上腺髓质中肾上腺素和去甲肾上腺素的含量，而SH则没有影响。这些结果表明，新生期暴露于IH和SH对嗜铬细胞急性低氧诱发的CA分泌和CA含量产生截然相反的影响。
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