Introduction: Corona is a group of viruses that result in respiratory infectious disease in birds, mammals and humans. One of the types of corona virus is Sars-Covid-2 which causes the disease of Covid-19. The main reason of death in patients which suffering from this virus have acute respiratory failure. Among other causes, we can mention the failure of several organs that leads to dysfunction of the heart, kidneys and etc. Sars-cov-2 is a type of enveloped virus with nucleocapsid ,membrane and simple single-stranded RNA. Corona virus has a crown-shaped structure called spike protein (s) which includes s1 and s2 subunits. SARS-CoV-2 uses the receptor of angiotensin-converting enzyme 2(ACE2) and it competes with angiotensin II to bind to the receptor of ACE2. By the initial connection of the S1 domain with the ACE-2 receptor, the S2 part of the virus causes the fusion of the host membrane with the virus membrane then the RNA virus can enter the host cell and motives a disruption in the expression of the enzyme gene and its reduction. This may cause an imbalance of the RAAS, a hormonal system that is responsible for a series of enzymatic reactions that mainly lead to the creation of angiotensin II and the regulation of blood pressure and body fluids. In this article, the relationship between Covid-19 and the renin-angiotensin system has been investigated.
Methods: This article was selected from the PubMed international database. The keywords of Covid-19, coronavirus, angiotensin were utilized. Then off-topic and duplicate sections were removed from the related articles.
Results: Importance of ACE2 in SARS-CoV had been studied by different scientists, Wenhui Li and teammates by testing on angiotensin-converting enzyme 2 and SARS-CoV, found that ACE2 is a functional receptor for SARS-CoV. Daniel Batlle and his teammates concluded by experimenting on mice using soluble recombinant protein ACE2 that it can be a new tool to fight the corona virus by limiting the attachment of the virus to the cell membrane. They also pointed out those studies on animals or humans using this method is not yet available and should be tested. Jun Mori and his teammates, by researching the different strategies to prevent spreading Covid-19, concluded that, the Sars-Covid-2 virus causes disturbances in the metabolism of the RAAS and the functioning of several organs, in addition to respiratory complications. They suggested that by restoring the balance in the RAAS, it is possible to the severity of the disease and mortality in patients with covid-19.
RAAS-blocking drugs are the most common ACE2 inhibitor as an
effective drugs for the management of COVID-19 but the effect of RAAS inhibitor for kidney patients are unknown, so for high-risk patients, RAAS inhibitor drugs should be recommended based on the patient's kidney function and clinical stability and doctors should be aware of the sudden discontinuation of RAAS and unwanted consequences based on empirical evidence. ARBs are antihypertensive drugs that block the angiotensin II receptor and affect the renin-angiotensin system.
There might be an association between antihypertensive drugs such as RAAS inhibitors, specifically ARBs, inhibitors and angiotensin-receptor blockers and the COVID-19 disease. Some studies have shown that ARBs in patients with acute lung injuries have a positive effect on the patient and may be useful. Mortality due to pneumonia in patients treated with ARBs is lower compared to patients treated with controlled treatment according to 37 meta-analysis studies.
Conclusion: In these studies, the significance of ACE2, RAAS as drugs targets were pointed out and it was found that the renin-angiotensin system, especially the ACE2 receptor, plays an important role in covid-19 and it is recommended to consider the renin-angiotensin system in the therapeutic aspects.