|
|
||||||||
RECEPTORS AND SIGNAL TRANSDUCTION
Heart and Kidney Institute, College of Pharmacy, University of Houston, Houston, Texas
Submitted 14 July 2008 ; accepted in final form 12 September 2008
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 86Rb (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 [35S]GTP
S 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, gp91phox 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.
dopamine; NADPH oxidase; G protein-coupled receptor; aging
This article has been cited by other articles:
![]() |
M. Asghar, G. Chugh, and M. F. Lokhandwala Inflammation compromises renal dopamine D1 receptor function in rats Am J Physiol Renal Physiol, December 1, 2009; 297(6): F1543 - F1549. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. George, M. F. Lokhandwala, and M. Asghar Exercise activates redox-sensitive transcription factors and restores renal D1 receptor function in old rats Am J Physiol Renal Physiol, November 1, 2009; 297(5): F1174 - F1180. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Yao, R. C. Harris, and M.-Z. Zhang Intrarenal Dopamine Attenuates Deoxycorticosterone Acetate/High Salt-Induced Blood Pressure Elevation in Part Through Activation of a Medullary Cyclooxygenase 2 Pathway Hypertension, November 1, 2009; 54(5): 1077 - 1083. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |