Biomaterial Database

Regulation of type 1 angiotensin II receptor and its subtype gene expression in kidney by sodium loading and angiotensin II infusion. 1996

D H Wang, and Y Du, and A Yao, and Z Hu

Department of Internal Medicine, Hypertension and Vascular Research Laboratories, University of Texas Medical Branch, Galveston 77555, USA.

OBJECTIVE To test the hypothesis that a high salt intake decreases gene expression of both type 1 angiotensin receptor subtypes 1A and 1B (AT1A and AT1B) and diminishes AT1 receptor density in the kidney through an angiotensin II (Ang II)-independent mechanism. METHODS Wistar rats were divided into four groups and fed a normal-sodium diet (0.5%, NSD), NSD + 25 ng/kg per min Ang II infusion, a high-sodium diet (4%, HSD), or HSD + Ang II infusion for 2 weeks. Quantitative reverse transcriptase-polymerase chain reaction was used for analysis of changes in renal AT1A and AT1B messenger RNA (mRNA) levels. Radioligand binding assays were used for measurement of Ang II receptor density. RESULTS Body weight and mean arterial pressure did not differ among the four groups. Renal AT1A and AT1B mRNA levels were decreased significantly in NSD + Ang II and HSD + Ang II groups compared with those in the NSD group. Renal AT1B mRNA was also decreased significantly in HSD versus NSD. The renal AT1 receptor density was decreased significantly in NSD + Ang II and HSD + Ang II, but was not changed in HSD compared with NSD. CONCLUSIONS A high salt intake downregulates the AT1B mRNA expression but does not change the AT1A mRNA expression and AT1 receptor density in the kidney, suggesting that differential regulation occurs in the kidney. Infusion of a nonpressor dose of Ang II, either alone or in conjunction with a high salt intake, downregulates the AT1 receptor and its subtype gene expression in the kidney, suggesting that Ang II regulates these responses through a negative feedback mechanism.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008297	Male		Males
D011945	Receptors, Angiotensin	Cell surface proteins that bind ANGIOTENSINS and trigger intracellular changes influencing the behavior of cells.	Angiotensin Receptor,Angiotensin Receptors,Angiotensin II Receptor,Angiotensin III Receptor,Receptor, Angiotensin II,Receptor, Angiotensin III,Receptor, Angiotensin
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D000804	Angiotensin II	An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.	Angiotensin II, Ile(5)-,Angiotensin II, Val(5)-,5-L-Isoleucine Angiotensin II,ANG-(1-8)Octapeptide,Angiotensin II, Isoleucine(5)-,Angiotensin II, Valine(5)-,Angiotensin-(1-8) Octapeptide,Isoleucine(5)-Angiotensin,Isoleucyl(5)-Angiotensin II,Valyl(5)-Angiotensin II,5 L Isoleucine Angiotensin II,Angiotensin II, 5-L-Isoleucine
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
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus