Celal Guven

By Eylem Taskin and Celal Guven

The systemic renin-angiotensin system mainly regulates blood pressure and maintains kidney function. Recent studies have realized that renin-angiotensin system (RAS) has been found in many tissues, such as heart, liver, and kidney. Although RAS in heart and kidney has been well documented, the RAS in the liver has been evaluated in a few studies. Therefore, this chapter will be assessed it. Based on findings, RAS in the liver has presented almost all of its components, such as angiotensin-I (Ang-I), angiotensin-II (Ang-II), angiotensin-converting enzyme (ACE), angiotensin type-1 receptor (AT1), angiotensin type-2 receptor (AT2), named as classical RAS. Expect these components, the local RAS has had alternative pathway components, including angiotensin-converting enzyme 2 (ACE2) and chymase. Classical RAS has an opposite effect of alternative RAS. Although these local RAS might not be such a crucial for the tissue, it could be a more vital function under pathophysiologic conditions. The chapter the local RAS in the liver the under both physiologic and pathophysiologic conditions is highlighted.

Part of the book: Renin-Angiotensin System

By Celal Guven, Yusuf Sevgiler and Eylem Taskin

Pyrethroids are used to decrease vector-based health concerns and to increase field yield against agricultural pests. Their metabolism is a concern to disrupt a cell’s homeostatic machinery via reactive oxygen species (ROS) production. They interact with lipid membranes to damage the fine balance between membrane lipids and membrane proteins, especially mitochondrial substrate transporters and electron carriers. Pyrethroids cause a shift in the metabolic energy production strategy, resulting in ROS production and intracellular lipid deposition. The change of open/closed conformation of some mitochondrial membrane proteins increases the vulnerability of mitochondria to Ca2+ ions. Membrane lipid fluidity change is also a concern because of permeability to the substrates and ions to produce energy and other substrates necessary for the cell. Pyrethroids can change the Ca2+ signaling and its interaction with ROS signals via disruption of the fine balance between endoplasmic reticulum and mitochondria. They can disrupt the mitochondrial DNA (mtDNA) via their hydrophobic nature or their ROS production capacity. In conclusion, mitochondria are the center of pyrethroid toxicity, and dysfunction of this organelle via pyrethroid toxicity plays an important role in the fate of cell. Their lipophilic and pro-oxidative nature together with Ca2+ homeostasis plays a synergistic role in this mitochondrial effect.

Part of the book: Mitochondrial Diseases

By Celal Guven, Yusuf Sevgiler and Eylem Taskin

Cancer prevalence is scaling up each year. Anthracycline groups are still the best chemotherapeutic agent. The most popular anticancer drug in the group is doxorubicin (DOX). Unfortunately, DOX has potent toxicity on noncancerous tissues, e.g., heart, kidneys, etc. However, it is well documented that the severest toxicity of the drug affects heart tissue. Of course, some reasons have been suggested why and/or how the heart is so vulnerable to toxicity. The primary mechanism responsible for DOX’s cardiospecific toxicity remains unidentified so far; however, mitochondrial dysfunction induced by DOX is now considered one of the leading reasons for DOX’s toxicities and undesired side effects. Mitochondrial reactive oxygen production in the heart is a significant contributor to developing mitochondrial dysfunction-exposed DOX based on a variety of evidence. The objective of this review chapter is to critically evaluate and highlight the role of mitochondria in the development of DOX-induced cardiotoxicity.

Part of the book: Mitochondrial Diseases