(796.9) Molecular Signalling Cascade Time in Sympathetic Stimulation of Angiotensin Renin Axis and Its Correlation With Ultra Low Frequency (ULF) of Heart Rate Variability (HRV)

Poster Board Number: A160

Edward Acero Mondragon (Universidad de La Sabana), Jorge Armando Cortes Cabrera (Universidad de La Sabana), John Jairo Gallego Correa (Universidad de La Sabana), Danial Antonio Urdaneta Paredes (Universidad de La Sabana), Luis Carlos Chaustre Nieto (Universidad de La Sabana), Samuel Ernesto Serrano Contreras (Universidad de La Sabana), Maria Paula Vasquez Bazurto (Universidad de La Sabana), Laura Daniela Zabala Rodíguez (Universidad Icesi)

INTRODUCTION

In Heart Rate Variability (HRV), Ultra Low Frequency Band (ULF) ranges between 0.003 to 0.03 Hz. It is believed that metabolism, body temperature as well as the renin-angiotensin axis is related to ULF.  Within juxtaglomerular cells, all the different biochemical events times may be quantified. Such chain of events start from B1 receptor activation, including renin secretion all the way through angiotensinogen conversion to angiotensin II. The present study’s objective  is to correlate sympathetic stimulation of juxtaglomerular cells to ULF bands found on heart rate variability.

MATERIAL AND METHODS

Google Scholar and National Library of Medicine databases were used to search articles  published between 1990 and 2021.  The time involved in juxtaglomerular cell intracellular signalling after sympathetic stimulation was searched, with the combination of the following terms: 1) ( ("Titer (TI) = (FRET), TI = (BRET), TI = (EDANS) and Adrenergic B1 activation time Gs protein activation Adenylate Cyclase activation time cAMP Activation time Activation time Protein Kinase A Renin Secretion Time Angiotensinogen Conversion Time Angiotensin I Conversion Time Angiotensin II Conversion Time In Vitro Cell Model Y)]. ” Inclusion criteria for each study consisted in Ligand-Receptor and renin related secretion cellular cascade timelines. Studies that satisfied the previously mentioned conditions were included.  Times for events that ranged from B1 adrenergic receptor activation, renin secretion all the way to angiotensinogen conversion to angiotensin II were estimated. Such times were added together and later converted in Hertz using time and frequency inverse relationship.

RESULTS

Juxtaglomerular cell signalling cascade involving B1 adrenergic receptor activation and its related renin secretion summed around 300 seconds. On the other hand, renin activation time to angiotensin 2 was 89 seconds. Once these values were added, total time was 389 seconds that once converted to frequency yielded a value of 0,00257 Hz. Such value is close to the lower limit of ULF bands that range between 0,003 and 0,03 Hz in HRV domain frequency.

CONCLUSIONS The biochemical sequence of events that start from renin secretion and ends in angiotensin II production takes approximately 389 seconds. Such time once converted, through the inverse relationship of time and frequency, is  0,00257 Hertz. Such value suggests that ULF band with HRV domain may correspond to renin angiotensin axis activity.

Grupo Proseim- Facultad de Medicina - Universidad de La Sabana