[Expression of citrate transporter mRNA in the kidneys of rats with metabolic acidosis].
The purpose of the present study was to examine whether metabolic acidosis affects the expression of rat renal Na(+)/citrate cotransporter. Female Wistar rats were pair-fed with normal rat chow and drinking water (control) or water with 0.28 mol/L NH4Cl (metabolic acidosis). The mRNA of two renal Na(+)/citrate cotransporters, which were respectively expressed on apical and basolateral membrane, were measured by Northern blot with two probes, SDCT1 and SDCT2. Animals were sacrificed on day 1,3 and 7. On the 1st day, the blood plasma HCO(-)3 of acidosis group decreased significantly (P<0.01), but the mRNA abundance did not change. On the 3rd day in the acidosis group, the blood plasma HCO(-)3 increased slightly more than that on the 1st day, but was still significantly lower than that of the control group (P<0.01). Both the probes detected some increase in mRNA of brush border and basolateral Na(+)/citrate cotransporter. On the 7th day, the blood plasma HCO(-)3 of the acidosis group continuously increased and there was no significant difference between the two groups. The abundance of brush border and basolateral Na(+)/citrate cotransporter mRNA increased, but there was no difference between those of the 3rd day and the 7th day. It is concluded that metabolic acidosis can induce increase of Na(+)/citrate cotransporter mRNA, which may be responsible for hypocitraturia.
Wu
D
D
Division of Nephrology, General Hospital of Chinese PLA, Beijing 100853, China.
Chen
X M
XM
Ye
Y Z
YZ
Cheng
Q L
QL
Wang
J Z
JZ
D000138:Acidosis / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D007668:Kidney / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
D002352:Carrier Proteins; D012333:RNA, Messenger; C020723:citrate-binding transport protein