Scientific Lecture on why “Asin” is “A Sin”
by Cyril Francis T. Wakit
A fruit gives back to its roots by providing seeds for the next generation to sprout. This is a metaphor for an outstanding alumnus who then served as an inaugural speaker of the same college where he was molded to be the successful physician, researcher, and professor he is now.
Dr. Pedro A. Jose, MD, PhD, a notable alumnus of the UST College of Liberal Arts (recently called College of Science) (AA, 1960) and MD (1965), and a Professor of George Washington University, imparted knowledge to the minds of academe and research, as he served as the Inaugural speaker of the Distinguished Alumni Lecture of the UST-College of Science this February 25, 2022, facilitated by Mr. Vitus Paul L. De Jesus, and Dr. Jose Paolo P. Aguilar, MD.
The lecture of Dr. Jose mainly revolved around Genetic and Salt Sensitivity of Blood Pressure. His discussion included the history of hypertension where he also presented the historical measuring of blood pressure by Stephen Hales (1773) as well as different insights of experts around the 19th century. Furthermore, Dr. Jose also discussed cross-renal transplantation on mice, in determining the importance of the kidney in regulating blood pressure (BP). The said study showed that transplanting syngeneic kidneys give systolic BP (SBP) similar to that of un-manipulated mice, whereas transplanting knock-out kidney to a wild-type body raises SBP and a wild-type kidney to a knock-out body lowers SBP. Hence, renal cross transplantation shows that BP regulation is 20% extrarenal and 80% renal.
Dr. Jose also tackled the epidemiology of Essential Hypertension and Health implications of increased salt intake, and then reminded everyone in the session that even if one has normal BP, high salt in-take can still increase BP, as well as BP being usually higher in time of waking up. He also discussed the three-week test of different salt level diets being the most reliable method for testing salt sensitivity. However, this is not paid by insurance in the US, thus, a urine test using renal proximal tubule cells was developed. He also presented risk groups of salt sensitivity such as women being more salt-sensitive than men are. Relating salt intake and hypertension, he pointed out that reducing daily salt intake would save life years and health costs annually. Salt intake was also said to have a relationship with mortality, and End-Stage Renal Disease (ESRD) in Diabetes wherein at points of high and of low salt in-take, there is increased hazard.
The pathogenesis of how salt in-take causes hypertension was also discussed in the lecture, which showed that increased sodium retention in the kidney causes increase in extracellular fluid which then stimulates other factors like vascular smooth muscle reactivity and endocrine factors, causing hypertension. The question then was how does the body control sodium levels? Dr. Jose tackled that long-term regulation rests on renal and non-renal mechanisms. To add, dopamine and phosphorylation also help regulate renal sodium transport, thus, deletion of dopamine receptor genes or uncoupling of the dopamine to its receptor may cause salt-sensitive hypertension. Thankfully, permeabilizing may assist coupling of uncoupling dopamine and receptor.
Genes can cause hypertension, as also tackled by Dr. Jose on each evidence: (1) linkage studies implying a chromosome of a so-called GRK4 is linked to essential hypertension; (2) sequence analysis correlating that the increase in GRK4 single nucleotide polymorphism increases odds of hypertension; (3) circumstantial evidence implying that expressed phenotype is as expected, and (4) definitive evidence involving transgenic mouse studies.
Dr. Jose then went back to discuss that renal and non-renal mechanisms control BP long-term regulation. Since natriuretic pathways were already previously implied, he then tackled the anti-natriuretic factors such as the effect of so-called SLC4A5 on low-renin salt-sensitive hypertension.
Concluding his lecture, Dr. Jose recommends that more studies must be conducted in bigger populations of different ethnicities to confirm the tackled human studies in his lecture. In fact, he eagerly added, “I would like to do these studies in the Philippines, so you could help me.” Lastly, he presented the benefits of avoiding high salt in-take, and he jokingly said that the reason why salt is bad is because “it is a sin … ASIN.”
Reference
Jose, P.A. (2022, February 25). Genetics and Salt Sensitivity of Blood Pressure [Lecture]. Distinguished Alumni Lecture of The College of Science, University of Santo Tomas — College of Science, Philippines.
