Korean J Nephrol.  2002 Jan;21(1):123-128.

Enhanced Atrial Natriuretic Peptide and Nitric Oxide System Following the Treatment with Caffeine in Rats

• Ha JH
• Yeum CH
• Kim SW
• Kim NH
• Choi KC
• Lee JU

Abstract

PURPOSE: The present study was aimed to examine whether caffeine alters the local regulation of atrial natriuretic peptide(ANP) and nitric oxide(NO) systems in the kidney.
METHODS
Male Sprague-Dawley rats were treated with caffeine, consisting of a single oral bolus(0.2%, 1 mL/kg) followed by supplementation in drinking water(0.2%) for 1 day. Rats treated the same without caffeine served as control. The tissue expression of ANP mRNA was determined by reverse transcription-polymerase chain reaction. Tissue levels of nitrite/nitrate were determined. The expression of aquaporin(AQP)-1 and AQP2 proteins was determined by Western blot analysis.
RESULTS
Following the treatment with caffeine, the expression of ANP mRNA was increased in the kidney. The renal tissue nitrite/nitrate level was also increased by caffeine-treatment. On the other hand, the expression of AQP1 and AQP2 proteins was not significantly altered.
CONCLUSION
The enhanced activities of local ANP and NO systems may in part be causally related with the caffeine-induced natriuresis and diuresis, while AQP channels are not involved.

Keyword

Caffeine; Atrial natriuretic peptide; Nitric oxide; Aquaporin

MeSH Terms

Animals
Aquaporin 2
Atrial Natriuretic Factor
Blotting, Western
Caffeine*
Diuresis
Drinking
Hand
Humans
Kidney
Male
Natriuresis
Nitric Oxide*
Rats*
Rats, Sprague-Dawley
RNA, Messenger
Aquaporin 2
Atrial Natriuretic Factor
Caffeine
Nitric Oxide
RNA, Messenger