| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Vascular Biology Center, Medical College of Georgia, Augusta, GA, USA
2 Vascular Biology Center, Medical College of Georgia, Augusta, GA, USA; Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta, GA, USA
3 Vascular Biology Center, Medical College of Georgia, Augusta, GA, USA; Department of Surgery, Medical College of Georgia, Augusta, GA, USA
4 Department of Physiology & Biophysics, University of Nebraska College of Medicine, Omaha, NE, USA
* To whom correspondence should be addressed. E-mail: jpollock{at}mail.mcg.edu.
Shear stress increases NO production by endothelial cells, inner medullary collecting duct cells, and thick ascending limb. We postulated that the osmotic diuresis accompanying type 1 diabetes is associated with increased NOS activity and/or expression in the renal medulla. Diabetes was induced by injection of streptozotocin, with insulin provided to maintain moderate hyperglycemia (HYP) or euglycemia (EUG) for 3 weeks. SHAM rats received vehicle treatments. A separate group of rats (PHZ) received phlorizin to produce a glucose-dependent osmotic diuresis. Renal medullary NOS1 and NOS2 activities did not differ between groups, whereas NOS3 activity was significantly increased in HYP. Neither NOS1 nor NOS3 protein levels differed significantly between groups. Reduced phosphorylation of NOS3 at Thr495 and Ser633 was evident in medullary homogenates from HYP rats, with no difference apparent at Ser1177. Immunohistochemical analysis indicated prominent expression of pThr495NOS3 in the thick ascending limb and collecting duct of SHAM and PHZ rats. HYP rats displayed staining in the collecting duct but minimal thick ascending limb staining. Immunostaining with anti-pSer1177NOS3 was evident only in the thick ascending limb, with no apparent differences between groups. In summary, glucose-dependent osmotic diuresis alone did not alter NOS activity or expression in the renal medulla. Diabetic hyperglycemia increased medullary NOS3 activity without a concomitant increase in NOS3 protein levels; however, NOS3 phosphorylation was reduced at Thr495 and Ser633. Thus, changes in the phosphorylation of NOS at known regulatory sites might represent the primary mechanism underlying increased renal medullary NOS activity in diabetic hyperglycemia.
This article has been cited by other articles:
|
|
 |
|
  J. M. Foster, P. K. Carmines, and J. S. Pollock PP2B-dependent NO production in the medullary thick ascending limb during diabetes Am J Physiol Renal Physiol, August 1, 2009; 297(2): F471 - F480. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Troncoso Brindeiro, R. W. Fallet, P. H. Lane, and P. K. Carmines Potassium channel contributions to afferent arteriolar tone in normal and diabetic rat kidney Am J Physiol Renal Physiol, July 1, 2008; 295(1): F171 - F178. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. P. Schneider, Y. Ge, D. M. Pollock, J. S. Pollock, and D. E. Kohan Collecting Duct-Derived Endothelin Regulates Arterial Pressure and Na Excretion via Nitric Oxide Hypertension, June 1, 2008; 51(6): 1605 - 1610. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Sullivan, L. Semprun-Prieto, E. I. Boesen, D. M. Pollock, and J. S. Pollock Sex and sex hormones influence the development of albuminuria and renal macrophage infiltration in spontaneously hypertensive rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2007; 293(4): R1573 - R1579. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Komers, W. E. Schutzer, J. F. Reed, J. N. Lindsley, T. T. Oyama, D. C. Buck, S. L. Mader, and S. Anderson Altered Endothelial Nitric Oxide Synthase Targeting and Conformation and Caveolin-1 Expression in the Diabetic Kidney Diabetes, June 1, 2006; 55(6): 1651 - 1659. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Herrera, P. A. Ortiz, and J. L. Garvin Regulation of thick ascending limb transport: role of nitric oxide Am J Physiol Renal Physiol, June 1, 2006; 290(6): F1279 - F1284. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Herrera, G. Silva, and J. L. Garvin A High-Salt Diet Dissociates NO Synthase-3 Expression and NO Production by the Thick Ascending Limb Hypertension, January 1, 2006; 47(1): 95 - 101. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Pollock and P. K. Carmines NOS3 Regulation: Renal Tubular Epithelial Cells Are Not Simply Large Endothelial Cells Hypertension, January 1, 2006; 47(1): 19 - 21. [Full Text] [PDF]
|
|
|
|
|
|
M. Herrera and J. L. Garvin Recent Advances in the Regulation of Nitric Oxide in the Kidney Hypertension, June 1, 2005; 45(6): 1062 - 1067. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
