Chronic infusion of low doses of atrial natriuretic factor (ANF Arg 101-Tyr 126) reduces blood pressure in conscious SHR without apparent changes in sodium excretion.
Conscious SHR and WKY rats were infused during 7 days with synthetic ANF (Arg 101-Tyr 126), 100 ng/hr/rat (35 pmol/hr/rat) by means of miniosmotic pumps. The SHR initial blood pressure of 177 +/- 5 mmHg gradually dropped to 133 +/- 3 and 142 +/- 4 mmHg the last two days of infusion. No significant change in blood pressure was observed in the ANF-infused WKY group. No apparent difference in natriuresis or diuresis was observed in ANF-infused SHR and WKY when compared with non-infused control groups. A slight but significant lower immunoreactive ANF concentration was found in the atria of SHR than in their normotensive controls. No difference in cardiac weight was found between infused and non-infused rats. It is suggested that the hypotensive response observed in SHR and not in WKY is due to a decrease in vascular peripheral resistance. Whether ANF is involved in the development and maintenance of high blood pressure in SHR remains to be elucidated.
D000818:Animals; D009320:Atrial Natriuretic Factor; D001794:Blood Pressure / Q000187:drug effects*; D006321:Heart / Q000033:anatomy & histology; D006973:Hypertension / Q000188:drug therapy*; D009124:Muscle Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D009318:Natriuresis / Q000187:drug effects*; D009929:Organ Size; D010446:Peptide Fragments / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D011919:Rats, Inbred Strains; D014655:Vascular Resistance / Q000187:drug effects
D009124:Muscle Proteins; D010446:Peptide Fragments; D009320:Atrial Natriuretic Factor; C043970:atrial natriuretic factor 26, rat