Biomaterial Database

Effect of dietary salt on neuronal nitric oxide synthase in the inner medullary collecting duct. 1998

A Roczniak, and J Zimpelmann, and K D Burns

Department of Cellular and Molecular Medicine, University of Ottawa and Ottawa General Hospital, Ottawa, Ontario, Canada K1H 8L6.

Nitric oxide (NO) derived from neuronal NO synthase (nNOS) in the kidney inner medulla has been implicated in the regulation of arterial blood pressure. The purpose of the present study was to determine the effect of high dietary NaCl on the expression of nNOS in the rat inner medullary collecting duct (IMCD). After 3 days or 3 wk of high (4.0%)-NaCl diet in rats, urinary NO-2/NO-3 excretion significantly increased. In freshly microdissected IMCD, nNOS was readily detected by immunofluorescence with polyclonal antibody, an effect that was completely blocked by neutralization of antibody with immunizing antigen. In rats fed a 4.0% NaCl diet for 3 days, IMCD nNOS mRNA, detected by RT-PCR, did not change from control values (0.3% NaCl, 19.84 +/- 1.57 x 10(3), vs. 4.0% NaCl, 20.44 +/- 3.14 x 10(3) cpm; P = not significant, n = 3). By Western blotting however, nNOS protein expression significantly increased (0.3% NaCl, 0.51 +/- 0.12, vs. 4.0% NaCl, 0.92 +/- 0.14 arbitrary units; P < 0. 05, n = 5). After 3 wk of 4.0% dietary NaCl, expression of nNOS mRNA and protein in IMCD did not differ significantly from control values. In contrast to these data, renal cortical expression of nNOS mRNA and protein was significantly decreased after 4.0% NaCl diet for 3 days. High dietary NaCl had no significant effect on expression of mRNA for inducible NO synthase (iNOS) in IMCD after either 3 days or 3 wk. In summary, our data indicate that nNOS mRNA and protein are expressed in IMCD and that high dietary NaCl differentially regulates nNOS expression in IMCD and cortex. The early increase in nNOS protein in IMCD may contribute to enhanced local production of NO and thereby represent an adaptive response to salt intake.

UI	MeSH Term	Description	Entries
D007679	Kidney Medulla	The internal portion of the kidney, consisting of striated conical masses, the renal pyramids, whose bases are adjacent to the cortex and whose apices form prominent papillae projecting into the lumen of the minor calyces.	Kidney Papilla,Kidney Medullas,Kidney Papillas,Medulla, Kidney,Medullas, Kidney,Papilla, Kidney,Papillas, Kidney
D007685	Kidney Tubules, Collecting	Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of Bellini) which opens on the summit of the papilla.	Kidney Collecting Ducts,Kidney Collecting Duct,Collecting Duct, Kidney,Collecting Ducts, Kidney
D008297	Male		Males
D009566	Nitrates	Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.	Nitrate
D009573	Nitrites	Salts of nitrous acid or compounds containing the group NO2-. The inorganic nitrites of the type MNO2 (where M	Nitrite
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D004039	Diet, Sodium-Restricted	A diet which contains very little sodium chloride. It is prescribed by some for hypertension and for edematous states. (Dorland, 27th ed)	Diet, Low-Salt,Diet, Low-Sodium,Diet, Salt-Free,Diet, Low Salt,Diet, Low Sodium,Diet, Salt Free,Diet, Sodium Restricted,Diets, Low-Salt,Diets, Low-Sodium,Diets, Salt-Free,Diets, Sodium-Restricted,Low-Salt Diet,Low-Salt Diets,Low-Sodium Diet,Low-Sodium Diets,Salt-Free Diet,Salt-Free Diets,Sodium-Restricted Diet,Sodium-Restricted Diets
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D012982	Sodium, Dietary	Sodium or sodium compounds used in foods or as a food. The most frequently used compounds are sodium chloride or sodium glutamate.	Dietary Sodium