title: Involvement of the V2 receptor in vasopressin-stimulated translocation of placental leucine aminopeptidase/oxytocinase in renal cells.
abstract: The placental leucine aminopeptidase (P-LAP)/oxytocinase is a membrane-bound enzyme thought to play an important role during pregnancy. In this study, we identified the presence of P-LAP protein in the renal distal tubules and collecting ducts. In rat NRK52E cells derived from renal tubules, P-LAP was localized mainly in the intracellular compartment. Upon the treatment of cells with 8-arginine-vasopressin (AVP), a significant increase in the surface level of P-LAP was observed. [deamino-Cys1, d-Arg8]-vasopressin (DDAVP), a specific V2 receptor agonist, increased the surface level of P-LAP, while [adamantaneacetyl1, O-Et-d-Tyr2, Val4, aminobutyryl6, Arg8,9]-vasopressin (AEAVP), a potent V2 receptor antagonist, blocked the AVP-stimulated enhancement. Moreover, reagents known to enhance the intracellular level of cAMP have also been shown to increase the surface level of P-LAP. When we examined the colocalization of P-LAP with the cell surface water channel aquaporin-2 (AQP-2) that is regulated by AVP, the P-LAP-containing vesicles had a relatively higher density than the AQP-2-containing vesicles, suggesting that P-LAP and AQP-2 are differently distributed in NRK52E cells. These results suggest that AVP induces the translocation of P-LAP via V2 receptor and P-LAP plays a role in the regulation of excessive AVP level in the renal collecting duct, acting as a negative feedback mechanism for the AVP action of regulating water reabsorption.
authors.affiliation: Laboratory of Cellular Biochemistry, RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama, Japan.
authors.forename: Shinako
authors.initials: S
authors.lastname: Masuda
authors.forename: Akira
authors.initials: A
authors.lastname: Hattori
authors.forename: Hideko
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Shinobu
authors.initials: S
authors.lastname: Miyazawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Natori
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Mizutani
authors.forename: Masafumi
authors.initials: M
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D051399:Aquaporin 2; D051403:Aquaporin 6; D020346:Aquaporins / Q000378:metabolism; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001692:Biological Transport; D002458:Cell Fractionation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D010122:Cystinyl Aminopeptidase / Q000378:metabolism*; D005260:Female; D007672:Kidney Cortex / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017483:Receptors, Vasopressin / Q000378:metabolism*; D022161:Transport Vesicles / Q000737:chemistry / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: C496025:Aqp2 protein, rat; D051399:Aquaporin 2; D051403:Aquaporin 6; D020346:Aquaporins; D017483:Receptors, Vasopressin; D014867:Water; D001127:Arginine Vasopressin; D010122:Cystinyl Aminopeptidase; C105964:leucyl-cystinyl aminopeptidase