Differential expression of amiloride-sensitive Na+ channel subunits messenger RNA in the rat uterus

The expression of the amiloride-sensitive Na+ channel was investigated by reverse transcription-polymerase chain reaction (RT-PCR) in uteri from pregnant and non-pregnant rats. Three subunits (alpha,beta,gamma) of this epithelial Na+ channel have been characterized in the rat. All three subunit mRNAs were present in day 16 pregnant uteri while only alpha and beta subunit mRNAs were detected in uteri from non-pregnant or day 1 postpartum rats. The level of expression of the alpha subunit was similar in day 16 pregnant and non-pregnant animals while the level of expression of the beta subunit was higher in pregnant than in non-pregnant rats. These findings show that amiloride-sensitive Na+ channels are expressed in the rat uterus and that mRNA expression levels of the alpha, beta and gamma subunits are selectively and differentially regulated during pregnancy in the rat. (C) 2000 Elsevier Science Inc.