Regulation of renal adenosine A(1) receptors: effect of dietary sodium chloride.
The influence of dietary NaCl on the regulation of renal adenosine A(1) receptors was investigated in the rat. Renal membranes from rats fed on a diet low (0.04%) in NaCl showed a 46% increase in B(max) for the binding of [3H]-1,3-dipropyl-8-cyclopentylxanthine ([3H]DPCPX), a selective adenosine A(1) receptor antagonist, compared to membranes from rats fed on a normal diet (0.4% NaCl). Conversely, a high NaCl diet (4.0%) resulted in a 37% decrease in B(max). Levels of renal adenosine A(1) receptor mRNA were 65% lower in rats on a high salt diet. Autoradiographic studies showed that, for the inner medullary collecting ducts, a low NaCl diet resulted in a 30% increase in [3H]DPCPX binding with a 39% decrease noted in rats maintained on a high salt diet. The results indicate that changes in adenosine A(1) receptor density may represent a novel mechanism whereby the kidneys adapt to changes in salt load.
Smith
J A
JA
School of Biomedical Sciences, Worsley Medical and Dental Building, University of Leeds, Leeds, UK.
Whitaker
E M
EM
Yaktubay
N
N
Morton
M J
MJ
Bowmer
C J
CJ
Yates
M S
MS
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012964:Sodium / Q000097:blood / Q000652:urine; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D014316:Tritium; D014970:Xanthines / Q000378:metabolism
D012333:RNA, Messenger; D018047:Receptors, Purinergic P1; D017673:Sodium Chloride, Dietary; D014970:Xanthines; D014316:Tritium; D012964:Sodium; C051360:1,3-dipropyl-8-cyclopentylxanthine