PT  - JOURNAL ARTICLE
AU  - Khalid, Mostafa
AU  - Giudicelli, Yves
AU  - Dausse, Jean-Pierre
TI  - An Up-Regulation of Renal α<sub>2</sub>A-Adrenoceptors Is Associated with Resistance to Salt-Induced Hypertension in Sabra Rats
DP  - 2001 Dec 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 928--933
VI  - 299
IP  - 3
4099  - http://jpet.aspetjournals.org/content/299/3/928.short
4100  - http://jpet.aspetjournals.org/content/299/3/928.full
SO  - J Pharmacol Exp Ther2001 Dec 01; 299
AB  - This study investigates the incidence of high-salt diet in blood pressures, renal α2-adrenoceptor subtypes distribution, and gene expression in salt-sensitive (SBH) and salt-resistant (SBN) Sabra rats. Comparisons have been made between SBH and SBN rats submitted to a normal or a high-salt diet for 6 weeks. Only α2B-adrenoceptors are detected in kidneys of SBH rats, whatever the diet. In contrast, mRNA corresponding to α2A- and α2B-subtypes are found in this substrain. In these rats, high-salt diet increases blood pressures and up-regulates gene expression and density of only α2B-adrenoceptors. Inversely, α2A- and α2B-adrenoceptors and corresponding mRNA are found in kidneys of SBN rats. In these rats, a high-salt diet does not affect blood pressures but increases gene expression and densities of both α2A- and α2B-adrenoceptors. If the up-regulation of renal α2B-adrenoceptor subtypes is indicative of the hypertensive phenotype, the present study shows that this mechanism is also present in normotensive salt-resistant Sabra rats. In fact, the absence of α2A-adrenoceptors in SBH could be responsible for the lack of adequate receptor-mediated renal functions predisposing to salt-sensitivity and consequently the development of hypertension. Conversely, the presence of this receptor in SBN rats and its up-regulation could be protective change against the increase of α2B-adrenoceptors induced by the salt overload and could consequently be responsible for the resistance to salt-induced hypertension. The American Society for Pharmacology and Experimental Therapeutics