Increased level of atrial natriuretic peptide messenger RNA in the hypothalamus and brainstem of spontaneously hypertensive rats.
OBJECTIVE
The aim of this study was to investigate atrial natriuretic peptide (ANP) gene expression in the central nervous system (CNS) during hypertension.


METHODS
We measured and compared immunoreactive atrial natriuretic peptide (irANP) and ANP messenger RNA (mRNA) in the hypothalamus and brainstem of 17-week-old spontaneously hypertensive rats (SHR) with those of age-matched Wistar-Kyoto (WKY) rats using ribonuclease (RNase) protection assay for ANP mRNA and a specific radioimmunoassay for irANP.


RESULTS
RNase protection assay revealed that the concentrations of ANP mRNA in the hypothalamus and brainstem of SHR were higher than those of WKY rats. IrANP concentrations in the hypothalamus and brainstem of SHR were determined by a specific radioimmunoassay and found to be higher than those of WKY rats. Elevated mRNA levels in the hypothalamus and brainstem of SHR indicated that increased level of irANP in the CNS resulted from increased synthesis of ANP.


CONCLUSIONS
We propose that increased synthesis of brain ANP in SHR may reflect a compensatory mechanism induced by hypertension.
Komatsu
K
K
Second Department of Internal Medicine, Hamamatsu University School of Medicine, Japan.
Tanaka
I
I
Funai
T
T
Ichiyama
A
A
Yoshimi
T
T
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000235:genetics*; D015152:Blotting, Northern; D001933:Brain Stem / Q000737:chemistry*; D015870:Gene Expression; D006973:Hypertension / Q000235:genetics* / Q000378:metabolism; D007031:Hypothalamus / Q000737:chemistry*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics*; D011863:Radioimmunoassay; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D012333:RNA, Messenger; D009320:Atrial Natriuretic Factor