scholarly journals A Pathophysiological Model for COVID-19: Critical Importance of Transepithelial Sodium Transport upon Airway Infection

Function ◽  
2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Martina Gentzsch ◽  
Bernard C Rossier

Abstract The Coronavirus Disease 2019 (COVID-19) pandemic remains a serious public health problem and will continue to be until effective drugs and/or vaccines are available. The rational development of drugs critically depends on our understanding of disease mechanisms, that is, the physiology and pathophysiology underlying the function of the organ targeted by the virus. Since the beginning of the pandemic, tireless efforts around the globe have led to numerous publications on the virus, its receptor, its entry into the cell, its cytopathic effects, and how it triggers innate and native immunity but the role of apical sodium transport mediated by the epithelial sodium channel (ENaC) during the early phases of the infection in the airways has received little attention. We propose a pathophysiological model that defines the possible role of ENaC in this process.

1976 ◽  
Vol 68 (4) ◽  
pp. 441-463 ◽  
Author(s):  
H N Nellans ◽  
S G Schultz

The relation between active transepithelial Na transport across rabbit ileum and 42K exchange from the serosal solution across the basolateral membranes has been explored. Although 42K influx across the basolateral membranes is inhibited by ouabain and by complete depletion of cell Na, it is not affected when transepithelial Na transport is abolished (i.e. in the presence of an Na-free mucosal solution) or stimulated (i.e. when glucose or alanine is added to the mucosal solution). We are unable to detect any relation between the ouabain-sensitive Na-K exchange mechanism responsible for the maintenance of intracellular Na and K concentrations and active transcellular Na transport. In addition, the maintenance of cell volume (water content) does not appear to be dependent upon transepithelial Na transport or the ouabain-sensitive Na-K exchange pump. Although the results of these studies cannot be considered conclusive, they raise serious questions regarding the role of the Na-K exchange pump, located at the basolateral membranes, in active transepithelial Na transport and the maintenance of cell volume.


2020 ◽  
Vol 152 (8) ◽  
Author(s):  
Morag K. Mansley ◽  
Christian Niklas ◽  
Regina Nacken ◽  
Kathrin Mandery ◽  
Hartmut Glaeser ◽  
...  

Prostaglandin E2 (PGE2) is the most abundant prostanoid in the kidney, affecting a wide range of renal functions. Conflicting data have been reported regarding the effects of PGE2 on tubular water and ion transport. The amiloride-sensitive epithelial sodium channel (ENaC) is rate limiting for transepithelial sodium transport in the aldosterone-sensitive distal nephron. The aim of the present study was to explore a potential role of PGE2 in regulating ENaC in cortical collecting duct (CCD) cells. Short-circuit current (ISC) measurements were performed using the murine mCCDcl1 cell line known to express characteristic properties of CCD principal cells and to be responsive to physiological concentrations of aldosterone and vasopressin. PGE2 stimulated amiloride-sensitive ISC via basolateral prostaglandin E receptors type 4 (EP4) with an EC50 of ∼7.1 nM. The rapid stimulatory effect of PGE2 on ISC resembled that of vasopressin. A maximum response was reached within minutes, coinciding with an increased abundance of β-ENaC at the apical plasma membrane and elevated cytosolic cAMP levels. The effects of PGE2 and vasopressin were nonadditive, indicating similar signaling cascades. Exposing mCCDcl1 cells to aldosterone caused a much slower (∼2 h) increase of the amiloride-sensitive ISC. Interestingly, the rapid effect of PGE2 was preserved even after aldosterone stimulation. Furthermore, application of arachidonic acid also increased the amiloride-sensitive ISC involving basolateral EP4 receptors. Exposure to arachidonic acid resulted in elevated PGE2 in the basolateral medium in a cyclooxygenase 1 (COX-1)–dependent manner. These data suggest that in the cortical collecting duct, locally produced and secreted PGE2 can stimulate ENaC-mediated transepithelial sodium transport.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 967-971
Author(s):  
Poonam Thakre ◽  
Waqar M. Naqvi ◽  
Trupti Deshmukh ◽  
Nikhil Ingole ◽  
Sourabh Deshmukh

The emergence in China of 2019 of severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) previously provisionally names 2019-nCoV disease (COVID19) caused major global outbreak and is a major public health problem. On 30 January 2020, the WHO declared COVID19 to be the sixth international public health emergency. This present pandemic has engrossed the globe with a high rate of mortality. As a front line practitioner, physiotherapists are expected to be getting in direct contact with patients infected with the virus. That’s why it is necessary for understanding the many aspects of their role in the identification, contains, reduces and treats the symptoms of this disease. The main presentation is the involvement of respiratory system with symptoms like fever, cough, sore throat, sneezing and characteristics of pneumonia leads to ARDS(Acute respiratory distress syndrome) also land up in multiorgan dysfunction syndrome. This text describes and suggests physiotherapy management of acute COVID-19 patients. It also includes recommendations and guidelines for physiotherapy planning and management. It also covers the guidelines regarding personal care and equipment used for treatment which can be used in the treatment of acute adult patients with suspected or confirmed COVID-19.


2018 ◽  
Vol 25 (23) ◽  
pp. 2627-2636 ◽  
Author(s):  
Vincenzo Calderone ◽  
Alma Martelli ◽  
Eugenia Piragine ◽  
Valentina Citi ◽  
Lara Testai ◽  
...  

In the last four decades, the several classes of diuretics, currently available for clinical use, have been the first line option for the therapy of widespread cardiovascular and non-cardiovascular diseases. Diuretic drugs generally exhibit an overall favourable risk/benefit balance. However, they are not devoid of side effects. In particular, all the classes of diuretics cause alteration of potassium homeostasis. <p> In recent years, understanding of the physiological role of the renal outer medullary potassium (ROMK) channels, has shown an intriguing pharmacological target for developing an innovative class of diuretic agents: the ROMK inhibitors. This novel class is expected to promote diuretic activity comparable to (or even higher than) that provided by the most effective drugs used in clinics (such as furosemide), with limited effects on potassium homeostasis. <p> In this review, the physio-pharmacological roles of ROMK channels in the renal function are reported, along with the most representative molecules which have been currently developed as ROMK inhibitors.


Author(s):  
A. Makrigiannakis ◽  
E. Zoumakis ◽  
S. Kalantaridou ◽  
G. Chrousos ◽  
A. Gravanis

2018 ◽  
Vol 18 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Luana da S.M. Forezi ◽  
Luana Pereira Borba-Santos ◽  
Mariana F.C. Cardoso ◽  
Vitor F. Ferreira ◽  
Sonia Rozental ◽  
...  

Sporotrichosis is a serious public health problem in Brazil that affects human patients and domestic animals, mainly cats. Thus, the search for new antifungal agents is required also due to the emergence and to the lack of effective drugs available in the therapeutic arsenal. The aim of this study was to evaluate the in vitro antifungal profile of two synthetic series of coumarin derivatives against Sporothrix schenckii and Sporothrix brasiliensis. The three-components synthetic routes used for the preparation of coumarin derivatives have proved to be quite efficient and compounds 16 and 17 have been prepared in good yields. The inhibitory activity of nineteen synthetic coumarins derivatives 16a-i and 17a-j were evaluated against Sporothrix spp. yeasts and the most potent compounds were 16b and 17i. However, according to concentrations able to inhibit (minimum inhibitory concentrations) and kill (minimum fungicidal concentrations) the cells, 17i was more effective than 16b against Sporothrix spp. Thus, 17i exhibited good antifungal activity against S. brasiliensis and S. schenckii, suggesting that it is an important scaffold for the development of novel antifungal agents.


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