[Effect of terbutaline on sodium transport in alveolar type I and type II cells].
OBJECTIVE
To explore the effect of terbutaline on sodium transport in rat alveolar type I (ATI) and type II (ATII) cells of rats.


METHODS
The whole cell currents were recorded from ATII cells isolated from rat lungs perfused with or without amiloride (inhibitor of epithelial sodium channel) and ZnCl(2) (inhibitor of cyclic nucleotide-gated cation channel) in the whole cell recording mode using the patch-clamp technique. The effect of terbutaline on the currents was examined.


RESULTS
The main currents recorded from ATII cells were amiloride-sensitive and Zn(2+)-sensitive. The amiloride-sensitive and Zn(2+)-sensitive current shared a similar proportion (P>0.05). Both currents could be significantly increased by terbutaline (P<0.05), and the proportion of amiloride-sensitive current was 1.7 times that of Zn(2+)-sensitive current (P<0.05).


CONCLUSIONS
There are functional epithelial sodium channels (ENaC) and cyclic nucleotide-gated cation channels (CNG) on freshly isolated ATII cells, both serving as the main channels for sodium transport. Terbutaline increases the absorption of alveolar fluid primarily by increasing sodium transport of ENaC and CNG on ATI and AT II cells.
Xu
Jian-guang
JG
Department of Sleep Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. hyl_0202@163.com
Li
Tao-ping
TP
Wang
Pei
P
Shen
Hai-yan
HY
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002712:Chlorides / Q000494:pharmacology; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000037:antagonists & inhibitors / Q000187:drug effects; D008297:Male; D010455:Peptides / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects*; D013726:Terbutaline / Q000494:pharmacology*; D017967:Zinc Compounds / Q000494:pharmacology
D002712:Chlorides; D054815:Cyclic Nucleotide-Gated Cation Channels; D010455:Peptides; D015222:Sodium Channels; D017967:Zinc Compounds; C029311:serum sodium transport inhibitor; D000584:Amiloride; C016837:zinc chloride; D012964:Sodium; D013726:Terbutaline