SEQ ID NO: 1: Gly-Gln-Arg-Glu for the treatment of autosomal recessive pseudohypoaldosteronism type 1 (PHA type 1B) or for the repair of the Na + transport ability of the loss-of-function mutant ENaC A cyclic polypeptide comprising at least 6 consecutive amino acids derived from the amino acid sequence of Thr-Pro-Glu-Gly-Ala-Glu-Ala-Lys-Pro-Trp-Tyr.常染色体劣性の偽性低アルドステロン症1型(PHA 1B型)の治療のため、または機能欠失型変異ENaCのNa+輸送能力の修復のための、配列番号1:Gly-Gln-Arg-Glu-Thr-Pro-Glu-Gly-Ala-Glu-Ala-Lys-Pro-Trp-Tyrのアミノ酸配列に由来する少なくとも6つの連続するアミノ酸を含む環状ポリペプチド。