SARS-CoV-2 binding to ACE2 triggers pericyte-mediated angiotensin-evoked cerebral capillary constriction

The SARS-CoV-2 receptor, ACE2, is found on pericytes, contractile cells enwrapping capillaries that regulate brain, heart and kidney blood flow. ACE2 converts vasoconstricting angiotensin II into vasodilating angiotensin-(1-7). In brain slices from hamster, which has an ACE2 sequence similar to human ACE2, angiotensin II alone evoked only a small capillary constriction, but evoked a large pericyte-mediated capillary constriction generated by AT1 receptors in the presence of the SARS-CoV-2 receptor binding domain (RBD). The effect of the RBD was mimicked by blocking ACE2. A mutated non-binding RBD did not potentiate constriction. A similar RBD-potentiated capillary constriction occurred in human cortical slices. This constriction reflects an RBD-induced decrease in the conversion of angiotensin II to angiotensin-(1-7). The clinically-used drug losartan inhibited the RBD-potentiated constriction. Thus AT1 receptor blockers could be protective in SARS-CoV-2 infection by reducing pericyte-mediated blood flow reductions in the brain, and perhaps the heart and kidney.

ACE inhibitors, AT1 receptor blockers and COVID-19: clinical epidemiology evidences for a continuation of treatments. The ACER-COVID study

AimsThe question of interactions between the renin angiotensin aldosterone system drugs and the incidence and prognosis of COVID-19 infection has been raised by the medical community. We hypothesised that if patients treated with ACE inhibitors (ACEI) or AT1 receptor blockers (ARB) were more prone to SARS-CoV2 infection and had a worse prognosis than untreated patients, the prevalence of consumption of these drugs would be higher in patients with COVID-19 compared to the general population.Methods and resultsWe used a clinical epidemiology approach based on the estimation of standardised prevalence ratio (SPR) of consumption of ACEI and ARB in four groups of patients (including 187 COVID-19 positive) with increasing severity referred to the University hospital of Lille and in three French reference samples (the exhaustive North population (n=1,569,968), a representative sample of the French population (n=414,046), a random sample of Lille area (n=1,584)).The SPRs of ACEI and ARB did not differ as the severity of the COVID-19 patients increased, being similar to the regular consumption of these drugs in the North of France population with the same non-significant increase for both treatment (1.17 [0.83–1.67]). A statistically significant increase in the SPR of ARB (1.56 [1.02–2.39]) was observed in intensive care unit patients only. After stratification on obesity, this increase was limited to the high risk subgroup of obese patients.ConclusionsOur results strongly support the recommendation that ACEI and ARB should be continued in the population and in COVID-19 positive patients, reinforcing the position of several scientific societies.

Position Paper of the Department of Hypertension of the Brazilian Society of Nephrology: Use of renin-angiotensin system blockers during the course of Covid-19 infection

ABSTRACT This position statement of the Department of Hypertension of the Brazilian Society of Nephrology (SBN) addresses the controversy surrounding the use or suspension/replacement of the renin-angiotensin-aldosterone system blockers (particularly inhibitors of the angiotensin-converting enzyme or angiotensin II AT1 receptor blockers) prophylactically in individuals using these drugs, due to the possibility of allegedly worsening the prognosis of hypertensive patients infected with SARS-CoV-2. The SBN Hypertension Department recommends individualizing treatment and maintaining these medications until better scientific evidence is available.

Angiotensin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

The actions of angiotensin II (Ang II) are mediated by AT1 and AT2 receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Angiotensin receptors [61, 152]), which have around 30% sequence similarity. The decapeptide angiotensin I, the octapeptide angiotensin II and the heptapeptide angiotensin III are endogenous ligands. losartan, candesartan, telmisartan, etc. are clinically used AT1 receptor blockers.