Gender-dependent response in blood pressure changes following the inhibition of nitric oxide synthase.
Many studies employed L-NAME (N(G)-nitro-L-arginine methyl ester), an L-arginine antagonist and nitric oxide (NO) synthase (NOS) inhibitor, to produce hypertension experimentally in male animals. It is not known whether females respond similarly. We thus examined the effect of long-term oral administration of L-NAME on body weight (BW), blood pressure (BP), and heart rate (HR) of both female and male rats. We found that L-NAME induced significant increase in mean BP (MAP) in both genders, however, L-NAME-treated females (F*) exhibited a significantly higher elevation than males (M*) did. This difference persisted for 5 wks and then diminished. L-NAME was thus withdrawn and a rapid decrease of MAP was observed. MAP of F* decreased less and thus remained higher than M* for 5 wks. MAP of control rats (F and M) remained unchanged during the period. Systolic BP (SBP) altered in a similar pattern. We also found that HR decreased immediately after L-NAME administration and that HR of F* was significantly less reduced. These findings indicate that L-NAME induced a more pronounced response in females than males, consistent with the view that females are more dependent on NOS activity for their regulation of BP.
Wang
Yu-Ren
YR
Department of Physiology and Pharmacology, Chang Gung University College of Medicine, Tao-Yuan, Taiwan, ROC.
Yen
Chia-Hung
CH
Sun
Ying-Fen
YF
Laun
Ying-Tung
YT
D000284:Administration, Oral; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004334:Drug Administration Schedule; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D005260:Female; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D011921:Rats, Inbred WKY; D012727:Sex Characteristics
D004791:Enzyme Inhibitors; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester