Objective: Recent studies identified overexpression of G-protein coupled receptors in adrenal adenomas, among which luteinizing hormone receptor (LHR). Clinically, its is known that plasma aldosterone levels may increase under LH stimulation, at least in females (Fommei, 2009). Aim of the study was to confirm LHR presence in aldosterone producing adenomas and assess the direct LH effect on aldosterone production in vitro, in a comparison with normal adrenals. Design and Method: After informed consent, adrenal fragments were collected from 16 hypertensive patients (7F/9M, mean age 66 years) during laparoscopic unilateral adrenalectomy for clinically confirmed primary aldosteronism due to unilateral adenoma and from normal adrenal glands of 6 cadaveric kidney normotensive donors (3F/3M, mean age 59 years). LHR was assayed by Western blotting analysis. Adrenal cell cultures from 12 hypertensive patients were also obtained and cortisol levels in supernatant measured as a marker of cell viability.Cells were then splitted and investigated both in the absence or presence of LH (300 ng/ml) in serum free-DMEM/F12 medium for 6 h. The supernatant was then assayed for aldosterone levels (Aldoctk-2RIA, Diasorin, Italy). Results: Western blotting analysis demonstrated LHR proteins as single bands at 85 kDa in all the explored adrenal tissues; however, LHR were more expressed in hypertensive patients than in normotensive kidney donors (1.71 ± 0.57 vs. 0.72 ± 0.21 mean ± SD of LHR/beta-actin; p < 0.001). LH stimulation of adrenal cells significantly increased aldosterone levels compared to unstimulated cultures in 5/12 patients, by a mean of 1.5 folds (p < 0.05). Conclusion: The results confirm LHR presence in human adrenal cortex and demonstrate an increased expression in Conn adenomas compared to normal adrenals. They also suggest the presence of LH dependent mechanism(s) on aldosterone secretion at least in subsets of human hyperaldosteronism.
A ROLE FOR LH IN ALDOSTERONE SECRETION: PRELIMINARY RESULTS OF AN IN VITRO STUDY ON CONN ADENOMAS AND NORMAL ADRENALS
FOMMEI, ENZA;MORELLI, LUCA
2012-01-01
Abstract
Objective: Recent studies identified overexpression of G-protein coupled receptors in adrenal adenomas, among which luteinizing hormone receptor (LHR). Clinically, its is known that plasma aldosterone levels may increase under LH stimulation, at least in females (Fommei, 2009). Aim of the study was to confirm LHR presence in aldosterone producing adenomas and assess the direct LH effect on aldosterone production in vitro, in a comparison with normal adrenals. Design and Method: After informed consent, adrenal fragments were collected from 16 hypertensive patients (7F/9M, mean age 66 years) during laparoscopic unilateral adrenalectomy for clinically confirmed primary aldosteronism due to unilateral adenoma and from normal adrenal glands of 6 cadaveric kidney normotensive donors (3F/3M, mean age 59 years). LHR was assayed by Western blotting analysis. Adrenal cell cultures from 12 hypertensive patients were also obtained and cortisol levels in supernatant measured as a marker of cell viability.Cells were then splitted and investigated both in the absence or presence of LH (300 ng/ml) in serum free-DMEM/F12 medium for 6 h. The supernatant was then assayed for aldosterone levels (Aldoctk-2RIA, Diasorin, Italy). Results: Western blotting analysis demonstrated LHR proteins as single bands at 85 kDa in all the explored adrenal tissues; however, LHR were more expressed in hypertensive patients than in normotensive kidney donors (1.71 ± 0.57 vs. 0.72 ± 0.21 mean ± SD of LHR/beta-actin; p < 0.001). LH stimulation of adrenal cells significantly increased aldosterone levels compared to unstimulated cultures in 5/12 patients, by a mean of 1.5 folds (p < 0.05). Conclusion: The results confirm LHR presence in human adrenal cortex and demonstrate an increased expression in Conn adenomas compared to normal adrenals. They also suggest the presence of LH dependent mechanism(s) on aldosterone secretion at least in subsets of human hyperaldosteronism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
