Vasopressin regulation of sodium transport in the distal nephron and collecting duct

Abstract

Arginine vasopressin (AVP) is released from the posterior pituitary gland during states of hyperosmolality or hypovolemia. AVP is a peptide hormone, with antidiuretic and antinatriuretic properties. It allows the kidneys to increase body water retention predominantly by increasing the cell surface expression of aquaporin water channels in the collecting duct alongside increasing the osmotic driving forces for water reabsorption. The antinatriuretic effects of AVP are mediated by the regulation of sodium transport throughout the distal nephron, from the thick ascending limb through to the collecting duct, which in turn partially facilitates osmotic movement of water. In this review, we will discuss the regulatory role of AVP in sodium transport and summarize the effects of AVP on various molecular targets, including the sodium-potassium-chloride cotransporter NKCC2, the thiazide-sensitive sodium-chloride cotransporter NCC, and the epithelial sodium channel ENaC.

Regulation of the Water Channel Aquaporin-2 via 14-3-3θ and -ζ

“…The finding that dDAVP increased 14-3-3␤ levels fits well with the known role of AVP to increase collecting duct NaCl transport (reviewed in Ref. 44). In principle, increased 14-3-3␤ would enhance the known 14-3-3␤ interaction with Nedd4-2, thereby inhibiting Nedd4-2-mediated ENaC ubiquitylation and ultimately increasing sodium transport (15,18,45).…”

Net K + secretion in the thick ascending limb of mice on a low-Na, high-K diet

“…Both AVP and angiotensin II (Ang II) are regulators of NKCC2. AVP increases NKCC2 expression via V2 receptor-mediated pathways 37 . However, studies showed that plasma and urinary AVP levels were either unchanged or decreased in animals fed a low Na diet 38–40 .…”

Circadian regulation of renal function

“…However, it has been suggested recently that AVP may play a more direct role in synchronizing the circadian network [65]. AVP is stored in the posterior pituitary gland until a number of different factors, such as plasma osmolality, hypotension, or hypovolemia, stimulate its release [66]. Plasma osmolality is seen as the most important factor behind AVP release, as miniscule changes in osmolality due to behavioral (increase/decrease in water or Na + intake) or physiological (increase/decrease in water or Na + excretion) mechanisms can influence AVP levels [67].…”

“…Plasma osmolality is seen as the most important factor behind AVP release, as miniscule changes in osmolality due to behavioral (increase/decrease in water or Na + intake) or physiological (increase/decrease in water or Na + excretion) mechanisms can influence AVP levels [67]. AVP has many different functions, including regulation of water retention in the body, inducing vasoconstriction to increase blood pressure, increasing the release of adrenocorticotropic hormone (ACTH), and influencing learning and memory [66]. There are many other autocrine and paracrine factors that also contribute to the regulation of water and electrolytes in this region, and will be touched on later in this review.…”