Diurnal and sex-specific renal responses to vasopressin receptor 2 agonism and antagonism in mice

Desmopressin (dDAVP) is more potent during the active phase in mice, resulting in a greater plasma dilution and a potential risk for hyponatremia. This time-of-day difference likely reflects increased water intake during the active period, as well as diurnal changes in renal physiology, including higher glomerular filtration, a stronger medullary interstitial osmotic gradient, and increased AQP2 phosphorylation at S256 that together promote greater water retention.