Secretion of medullipin I by isolated kidneys perfused under elevated pressure.
1. Medullipin I (Med I) is a hormone extracted from renal papillae and its renomedullary interstitial cells (RIC). Med I is stimulated by elevation of the renal artery perfusion pressure. 2. When isolated normal rat kidneys were perfused either with oxygenated blood or with 5% albumin bubbled with O2 at elevated perfusion pressures, Med I appeared to be secreted into the renal venous effluent (RVE). Addition of Tween 20, treatment of the assay rat with SKF 525A, inhibitor of cytochrome P-450 and removal of the liver from the systemic circulation prevented vasodepression of both the RVE and extracted Med I. The lipid in the RVE gave the same dose-response as extracted Med I. 3. Lowering the renal artery perfusion pressure below normal inhibited the secretion of Med I. As the perfusion pressure was elevated Med I secretion appeared to increase. 4. Previous observations and the present study support the view that the renin-angiotensin system and the Medullipin system are double feedback systems involved in blood pressure control.
Department of Pathology, University of Tennessee, Memphis.
E E
EE
Muirhead
B
B
Brooks
L W
LW
Byers
P
P
Brown
J A
JA
Pitcock
D000804:Angiotensin II / Q000096:biosynthesis; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D006978:Hypertension, Renovascular / Q000503:physiopathology*; D066298:In Vitro Techniques; D007668:Kidney / Q000098:blood supply / Q000378:metabolism*; D015289:Leukotrienes / Q000096:biosynthesis; D050356:Lipid Metabolism; D008055:Lipids; D008297:Male; D010477:Perfusion; D011136:Polysorbates / Q000494:pharmacology; D011335:Proadifen / Q000494:pharmacology; D011453:Prostaglandins / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D012077:Renal Artery / Q000502:physiology
D015289:Leukotrienes; D008055:Lipids; D011136:Polysorbates; D011453:Prostaglandins; C050534:medullipin I; D000804:Angiotensin II; D011335:Proadifen