Renal proximal tubules from old Fischer 344 rats grow into epithelial cells in cultures and exhibit increased oxidative stress and reduced D1 receptor function.
Earlier we reported defects in D1 receptor function in renal proximal tubules (RPTs) of aged Fischer 344 (F344) and obese Zucker rats. However, the defects in the receptor function in RPTs of obese Zucker rats do not pass onto primary cultures of RPTs from these animals. Here, we determined whether the defects in D1 receptor function in RPTs of aged F344 rats pass onto the primary cultures. RPTs from aged (24-mo) and adult (6-mo) F344 rats were grown into primary cultures. The microscopic studies showed that cells in cultures from adult and old rats were healthy as determined by the shape and size of the cells and nuclei. D1 receptor agonist SKF-38393 produced inhibition of (86)Rb (rubidium) uptake, index of Na-K-ATPase activity, in cells from adult rats, but this was reduced in old rats. Also, SKF-38393 increased the [(35)S]GTPgammaS binding, index of receptor activation, in the membranes of cells from adult rats but to a lesser extent from old rats. Furthermore, there was a downward trend in the levels of D1 receptor numbers and in the receptor proteins in old rats. Interestingly, gp(91phox) subunit of NADPH oxidase and cellular protein carbonyl levels (oxidative stress marker) were higher in cultures from old rats. These results show that RPTs from adult and old F344 rats grow into epithelial cells in cultures. Furthermore, cells in cultures from old rats are at a higher level of oxidative stress, which may be contributing to the reduced D1 receptor function in the cells from old compared with adult rats.
Asghar
Mohammad
M
Heart and Kidney Institute, College of Pharmacy, Univ. of Houston, Houston, TX 77204, USA. masghar@mail.uh.edu
Chillar
Annirudha
A
Lokhandwala
Mustafa F
MF
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D018491:Dopamine Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism; D018384:Oxidative Stress; D050050:Protein Carbonylation; D051381:Rats; D011916:Rats, Inbred F344; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism
D018491:Dopamine Agonists; D008562:Membrane Glycoproteins; D017447:Receptors, Dopamine D1; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; C500593:Cybb protein, rat; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D000254:Sodium-Potassium-Exchanging ATPase
Exp Biol Med (Maywood). 2003 Feb;228(2):134-42
12563019
Curr Hypertens Rep. 2000 Apr;2(2):174-83
10981146
Toxicol Appl Pharmacol. 2007 Jun 15;221(3):349-62
17481684
Hypertension. 1999 Apr;33(4):1036-42
10205244
Am J Physiol Renal Physiol. 2004 Jul;287(1):F109-16
15068975
Cell Mol Life Sci. 2001 Jul;58(8):1150-8
11529507
Kidney Int. 2000 Aug;58(2):712-20
10916094
Free Radic Biol Med. 2007 Mar 15;42(6):756-64
17320758
Proc Natl Acad Sci U S A. 2000 Jul 5;97(14):8010-4
10869423
Circ Res. 2008 Feb 29;102(4):439-47
18096819
Br J Pharmacol. 2008 Apr;153(7):1445-55
18297111
Physiol Genomics. 2004 Nov 17;19(3):233-46
15548830
Brain Res. 2007 Jul 9;1157:156-66
17537410
Proc Natl Acad Sci U S A. 2002 Mar 19;99(6):3872-7
11904438
J Mol Biol. 2006 Jul 7;360(2):251-7
16765377
Hypertension. 2001 Sep;38(3):297-302
11566894
Am J Cardiol. 1988 Jun 15;61(16):7H-12H
3289354
Proc Natl Acad Sci U S A. 2001 Mar 13;98(6):3001-5
11248021
Curr Hypertens Rep. 2001 Apr;3(2):165-71
11276400
Hypertension. 2003 Jun;41(6):1353-8
12707290
J Gerontol. 1991 Mar;46(2):B72-7
1997567
Am J Physiol Heart Circ Physiol. 2007 Jul;293(1):H829-35
17468330
Clin Exp Hypertens. 2003 Nov;25(8):509-15
14649308
Exp Mol Pathol. 1997 Feb;64(1):1-11
9203504
J Alzheimers Dis. 2006 Sep;10(1):9-16
16988475
Mol Cell Biochem. 2007 Oct;304(1-2):93-9
17503004
J Am Soc Nephrol. 1996 Aug;7(8):1106-22
8866401
Am J Physiol Regul Integr Comp Physiol. 2005 Oct;289(4):R913-35
16183628
Circ Res. 2005 Oct 14;97(8):829-36
16151024
Mutagenesis. 1996 May;11(3):281-4
8671749
Free Radic Biol Med. 1994 Nov;17(5):429-37
7835749
Kidney Int. 2004 Jan;65(1):219-27
14675053
Am J Physiol Renal Physiol. 2006 Nov;291(5):F945-51
16757732
Toxicology. 2000 Sep 7;150(1-3):83-98
10996665
Exp Biol Med (Maywood). 2004 Mar;229(3):270-5
14988520