Changes in central and peripheral renin-angiotensin system after furosemide injection.
To examine the effects of acute stimulation on the peripheral and central renin-angiotensin system, simultaneous sampling of blood and cerebrospinal fluid (CSF) for measurements of plasma renin activity (PRA), plasma angiotensin I-immunoreactivity (PAng I-ir), plasma angiotensin II-immunoreactivity (PAng II-ir), plasma angiotensinogen and cerebrospinal fluid angiotensin II-ir (CSF Ang II-ir) and CSF angiotensinogen was carried out following intravenous injection of furosemide (5 mg/kg) in conscious dogs. Administration of furosemide induced marked increases in PRA, Ang I-ir, PAng II-ir and CSF Ang II-ir, however, neither plasma nor CSF angiotensinogen was changed. Furthermore, a relatively large dose (20 mg/kg/min) of intravenously infused synthetic Ang II for 20 min produced a five-fold increase in PAng II-ir compared with no significant increase in CSF Ang II-ir. In spite of significant suppression of PRA and PAng I-ir, there were no significant changes in either plasma or CSF angiotensinogen. These results primarily suggest that the peripheral and the brain renin-angiotensin systems may be linked and that acute changes in the peripheral renin-angiotensin system do not alter either plasma or CSF angiotensinogen.
D000803:Angiotensin I / Q000097:blood / Q000134:cerebrospinal fluid; D000804:Angiotensin II / Q000097:blood / Q000134:cerebrospinal fluid; D000808:Angiotensinogen / Q000097:blood / Q000134:cerebrospinal fluid; D000818:Animals; D004285:Dogs; D005665:Furosemide / Q000494:pharmacology*; D008297:Male; D012083:Renin / Q000097:blood / Q000134:cerebrospinal fluid; D012084:Renin-Angiotensin System / Q000187:drug effects*
D000808:Angiotensinogen; D000804:Angiotensin II; D005665:Furosemide; D000803:Angiotensin I; D012083:Renin