Original papers: Adrenergic mechanismsα1-Adrenergic receptor subtypes in peripheral blood lymphocytes of essential hypertensivesVeglio, Francoa; Tayebati, Seyed Khosrowc; Schiavone, Domenicaa; Ricci, Albertob; Mulatero, Paoloa; Bronzetti, Elenab; Rabbia, Francoa; Amenta, Francescoc Author Information aDepartment of Medicine and Experimental Oncology, Hypertension Unit, University of Turin, Turin; bDepartment of Cardiovascular and Respiratory Sciences, ‘La Sapienza’ University, Rome and cSection of Human Anatomy, Department of Pharmacological Sciences and Experimental Medicine, University of Camerino, Camerino, Italy. Correspondence and requests for reprints to Franco Veglio, Dipartimento di Medicina e Oncologia Sperimentale, Ospedale San Vito, Strada San Vito 34, 10133 Torino, Italy. Tel: +39 011 633 6937; fax: +39 011 660 2707; e-mail: [email protected] Received 28 August 2000 Revised 6 March 2001 Accepted 14 May 2001 Journal of Hypertension 19(10):p 1847-1854, October 2001. Buy Abstract Objective The expression of α1-adrenergic receptor subtypes in peripheral blood lymphocytes was investigated in 28 essential hypertensive patients as well as in the peripheral blood lymphocytes and aorta of spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto (WKY) rats. Methods α1-Adrenergic receptors were quantified by radioligand binding assays, employing [3H]-prazosin as the radioligand in association with compounds displaying different degrees of selectivity for α1A-, α1B- and α1D-adrenergic receptor subtypes. Results The affinity of [3H]-prazosin binding was similar in peripheral blood lymphocytes of different stage essential hypertensive and normotensive subjects or of SHR and age-matched normotensive WKY rats as well as in the aortas of SHR and WKY rats. The radioligand binding assay revealed no change in the expression of α1-adrenergic receptors in peripheral blood lymphocytes of essential hypertensives compared with normotensive subjects; a moderate decrease of α1B-adrenergic receptors and an increase of α1D-adrenergic receptors. The relative densities of the α1-adrenergic receptor subtypes were similar in the three groups of essential hypertensives. In peripheral blood lymphocytes and in aorta of SHR, [3H]-prazosin binding was significantly reduced compared with normotensive WKY rats. The expression of α1-adrenergic receptor subtypes in peripheral blood lymphocytes of SHR was similar to that found in peripheral blood lymphocytes of essential hypertensives. Conclusions Changes of lymphocyte α1-adrenergic receptor subtypes in essential hypertensives are similar to those observed in lymphocytes and vascular tissues of animal models of hypertension. This suggests that assays of lymphocyte α1-adrenergic receptors may represent an indirect marker of their involvement in essential hypertension. © 2001 Lippincott Williams & Wilkins, Inc.