Effect of microsomal leucine aminopeptidase from human placenta (microsomal P-LAP) on pressor response to infused angiotensin II (A-II) in rat.
The role of microsomal placental leucine aminopeptidase (microsomal P-LAP) in the decreased pressor responsiveness to angiotensin II (A-II) in pregnancy was studied. Appreciable amounts of microsomal P-LAP activity were found in rat placenta. The similar dose to the endogenous activity, of human microsomal P-LAP exogenously administered to rats, resulted in significant decrease in the response to A-II. Bestatin, an inhibitor of the microsomal leucine aminopeptidase administered to pregnant rats, enhanced the A-II response. Therefore our present study suggests such refractoriness in response to A-II in pregnancy is due to increased inactivation by the microsomal P-LAP. It was also suggested that prostaglandins were not involved in such refractoriness by the experiments with indomethacin.
Mizutani
S
S
Department of Obstetrics and Gynecology, Nagoya University School of Medicine, Japan.
Taira
H
H
Kurauchi
O
O
Ito
Y
Y
Imaizumi
H
H
Furuhashi
M
M
Narita
O
O
Tomoda
Y
Y
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D007931:Leucyl Aminopeptidase / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D010920:Placenta / Q000201:enzymology* / Q000648:ultrastructure; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains
D000804:Angiotensin II; D007931:Leucyl Aminopeptidase; D007930:Leucine; C012211:ubenimex; D007213:Indomethacin