Dániel Sugár1, Róbert Agócs1, Domonkos Pap1, Endre Sulyok3, Attila J. Szabó1,2, Tivadar Tulassay1,2
1 Semmelweis University, First Department of Pediatrics, Research Laboratory, Budapest
2 HAS-SE Nephrology Research Laboratory, Budapest
3 University of Pécs, Faculty of Health Sciences, Pécs
Introduction: Data from the literature suggests that dietary sodium bound to the negatively charged glycosaminoglycan (GAG) molecules of the skin may modulate the local renin–angiotensin system (RAS) of the skin, and may initiate tissue remodelling and vasoconstriction.
Aims: The aim of our study was to investigate the activation of the components of the local skin RAS system, their regulation and the effect they have on blood pressure in a salt overloaded rat model.
Methods: 36 eight-week-old male Sprague Dawley rats were fed either on low salt (LSD, NaCl<0,01% m/m), normal salt (NSD, NaCl= 0,3% m/m ) or high salt (HSD, NaCl = 8% m/m) diet for 4 weeks. Basic physiological parameters (body mass, blood pressure), as well as food and water consumption, urine volume and composition were measured during the whole length of the experiment. At the end of the experiment, tissue samples were collected for molecular (qRT-PCR, western blot, immunhistochemistry) investigations.
Results: By week 3., significant rise in systolic blood pressure was detected in HSD group (n=36, p<0.01). Elevated levels of skin angiotensinogen (AGT) mRNA levels were detected in the HSD group compared to the NSD group (n=21, p<0.01). The mRNA levels of the (P)RR receptor exhibited a change close to the level of significance (n=21, p=0.08). In the HSD rats, no decrease was detected in the mRNA levels of the other measured RAS components (n=21; ACE : p=0,72 vs NSD; ACE2 : p=0,19 vs NSD).
Conclusion: The elevated skin AGT mRNA level, the almost significant change in (P)RR mRNA receptor levels as well as the lack of decrease in the level of ACE expression implies the activation of the skin local RAS system per se. Further investigations are needed to determine the role of the remaining RAS components (renin, angiotensin 1 and 2 receptor).
Doctoral School: Clinical Medicine
Program: Prevention of chronic diseases in childhood
Supervisor: Attila J. Szabó
oral / poster presentation
„This investigation was founded by the ÚNKP-17-3-III-SE-31 grant of the Ministry of Human Capacities and the OTKA grant K125470.”