Erythrocyte Na⁺,K⁺‐ATPase and nasal potential in pseudohypoaldosteronism*

Abstract

The observed differences in RBC Na+,K+-ATPase activity and nasal PD response to amiloride between the two pairs of twins support the contention of different basic pathogenic mechanisms in the two forms of PHA1.

A novel splice site mutation of the beta subunit gene of epithelial sodium channel (ENaC) in one Turkish patient with a systemic form of pseudohypoaldosteronism type 1

“…Renin and aldosterone levels decreased to normal values at 1 year old, with high amounts of NaCl, similar to the results reported in Bistritzer et al (13) . Severe multi-system PHA patients show significant growth retardation because chronic salt-loss impairs growth velocity (8) .…”

“…However, increases in PRA and aldosteron levels and salt requirement continued with age. Bistritzer et al (13) reported that, in twins with systemic PHA, PRA and aldosterone levels had reverted to normal values by the end of the first year of life, after therapy with large amounts of dietary salt. The authors considered that this improvement may be associated with reduced dependence on aldosterone action in salt homeostasis with increasing age and alternative regulating mechanisms in sodium homeostasis.…”

Renin–aldosterone response, urinary Na/K ratio and growth in pseudohypoaldosteronism patients with mutations in epithelial sodium channel (ENaC) subunit genes

“…In A6 cells aldosterone has been shown to increase the expression of Na + -K + -ATPase [25]. However, in a study on PHA patients red blood cell activity Na + -K + -ATPase was found to be low [16], but this does not necessarily reflect the levels of this important pump in kidney and other relevant organs. Aldosterone has been reported to regulate Na-K-Cl co-transporter isoform NKCC1 in vascular smooth muscle [26] but it is not known whether it also regulates the NKCC2 isoform found in the kidney [27].…”

“…Two previous studies that have examined multi-system PHA patients up to 7-9 years of age have not included long-term evaluation of the PRA, aldosterone or urinary Na/K ratio [8,15]. Bistritzer et al reported PRA and aldosterone levels in a pair of twins with multisystem PHA up to 6 years of age [16].…”

Structure and Function of CLCA Proteins

“…Inflammation may trigger this phenotypic switch to help flush particulates and secreted mucus out of the airway. Pseudohypoaldosteronism is an excellent model for this strategy, where increasing net secretion by decreasing absorption significantly increases the rate of mucociliary clearance (18,40,97).…”