Effects of intranasal administration of atrial natriuretic hormone on spontaneously hypertensive rats.
The effects of the intranasal administration of synthetic alpha-human atrial natriuretic polypeptide (alpha-hANP) were investigated in 14 anesthetized spontaneously hypertensive rats (SHR; Okamoto-Aoki strain). They were given intranasally synthetic alpha-hANP in distilled water at doses of 10 micrograms/kg, 50 micrograms/kg and 100 micrograms/kg. Intranasal application of 200 microliter of distilled water as a control was also performed in 3 anesthetized SHR. Sixteen anesthetized SHR were examined for the effects of intravenous administration of alpha-hANP at doses of 4 micrograms/kg, 10 micrograms/kg, 20 micrograms/kg and 40 micrograms/kg. Urinary volume and the urinary excretion of sodium increased 2- to 3-fold during the 50 minutes following intranasal administration of a single dose of 50 micrograms/kg or 100 micrograms/kg, although neither the urinary volume nor the urinary excretion of sodium increased after intranasal administration of 10 micrograms/kg of alpha-hANP or 200 microliter of distilled water. There were no significant changes in arterial pressure or heart rate after the intranasal administration of synthetic alpha-hANP or distilled water. In contrast, arterial pressure was decreased and urinary volume and urinary excretion of sodium were increased, in a dose dependent manner, within 5 minutes after intravenous bolus-injection of alpha-hANP and returned to their baseline levels within 20 minutes. These results indicate that intranasal administration of synthetic alpha-hANP exerts its diuretic effect without concomitant changes in arterial pressure or heart rate in SHR.
D000281:Administration, Intranasal; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000008:administration & dosage* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000503:physiopathology*; D007671:Kidney Concentrating Ability / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D012964:Sodium / Q000652:urine
D009320:Atrial Natriuretic Factor; D012964:Sodium