How Aged Kidneys Can Be Impacted by Salt Intake

Chugh, G., Pokkunuri, I., Asghar, M. (2013). Renal dopamine and angiotensin II receptor signaling in age-related hypertension. Am J Physiol Renal Phyiol, 304: F1-F7. The researchers discuss the roles of dopamine and angiotensin II in the kidneys in regulating blood pressure. The study is focused on recent analysis of the way in which these renal receptors signal to one another and how these signals are factored into the process of the body's aging.

The study examines the history of research on the subject of the rennin-angiotension system and the renal dopaminergic system and explores new findings related to the process of blood pressure regulation by posing questions, such as, "Do tissue factors, especially dopamine, change during renal aging?" (p. F2). The study discusses the ramifications of targeting specific receptors with agonists and antagonists in order to thwart renal aging and stem the effects of this process among geriatrics. Chugh, G., Lokhandwala, M., Asghar, M. (2012).

Altered functioning of both renal dopamine D1 and Angiotensin II type 1 receptors causes hypertension in old rats. Hypertension, 59: 1029-1036. This study identifies the cause of hypertension in aged rats as being dopamine D1 and angiotensin II type 1 receptors. This study is complimentary to the other study led by Chugh (2013) and gives the findings of the experiment conducted in order to assess the role of these two receptors in the development of hypertension, using aged rats as the sample.

The findings of this study reveal extensive analysis of a number of receptors, proteins, controls, and their relation to increases in blood pressure, and the underlying factor of an "increase in oxidative stress" which changes the DIR and ATR renal receptors pivotal in the regulation of the blood pressure (p. 1035). Wiggins, J. (2011). Why do our kidneys get old? Nephron Exp Nephrology, 119(suppl 1): e1-e5.

Wiggins's study analyzes the fact that kidneys must deal with the aging of the body in the same as everything else and that stress affects this process, as both salt and acid contents become less easy to process. Wiggins explores the ideas connected to the aging downturn in effectiveness of the kidneys to process the body's contents and what can be learned in terms of renal receptors.

Wiggins essentially dissects the biological function of the kidneys to provide the reader with a detailed description of how the process works, how the cells interact, and the roles that are played. In examining these functions, the researcher also explores possible explanations for how the kidneys are affected by aging: for example, the researcher highlights the "recent data that suggests that reduced signaling of the IGF-1 pathway may play a role" (p.

e4) though Wiggins also asserts that such data does not really convey any useful therapy in terms of actually being effective in stabilizing the kidneys against old age. Montasser, M. et al. (2011). Determinants of blood pressure response to low-salt intake in a healthy adult population. Journal of Clinical Hypertension, 13(11): 795-799. This study examines the impact of the salty diet on the blood pressure.

The researchers experiment on whether sodium impacts BP by performing a test of systolic BP after a diet of low-sodium in an Amish community of normal, healthy individuals. The participants each partook of a high and low sodium diet for the duration of the six-day experiment, each diet occurring on the other end of a "cleansing" period of one to two weeks.

What the researchers found was that the major factor in whether salt affected systolic BP was the age of the individual participant, indicating that age and its impact on the kidney's ability to process salt was the major determinant in the relationship between salt and blood pressure. The researchers also established a connection between salt and the impact on BP in women during nocturnal hours.

The study concludes with the suggestion that lowering salt intake in older individuals and women could positively impact the blood pressure and reduce high blood pressure significantly over time so as to better facilitate the function of the kidneys. Salyer, S. et al. (2011). Dopamin regulation of Na+ -K+ -ATPase requires the PDZ-2 domain of sodium hydrogen regulatory factor-1 (NHERF-1) in opossum kidney cells. Am J Physiol Cell Physiol, 300: C425-C433. This study examines the sodium-potassium pump and how it is affected by PTH plus dopamine.

The researchers experiment with sodium hydride exchanger regulatory factor 1 (NHERF-1) to impact/regulate the sodium-potassium pump, using dopamine. The study focuses primarily on the impact of dopamine on the mutated OKH cells touched by PDZ-2. However dopamine did impact PDZ-1 mutated OKH.