Interactions between the renin-angiotensin system and prostanoids in modulating renal function in potassium-depleted healthy women.
Plasma renin activity (PRA) and urinary aldosterone excretion were determined in healthy women with normal potassium balance (N, n = 20) or experimental potassium depletion (KD). KD was induced by natriuretic treatment--associated with replacement of net NaCl and water losses--and low dietary potassium intake (< or = 10 mmol/d). By using different depletion patterns, three groups were obtained with cumulative potassium deficits (mean +/- SEM) of 160 +/- 43 (KD1, n = 8), 198 +/- 22 (KD2, n = 6) and 215 +/- 54 mmol (KD3, n = 6). The renal function by the clearance (cl.) method and urinary concentrations of prostaglandin E2 (PGE2), 6-keto-PGF1 alpha (6KPGF), and thromboxane B2 (TXB2) by the RIA method were estimated during hypotonic polyuria (oral water load) and subsequent moderate antidiuresis induced by low-dose infusion of lysine-8-vasopressin (LVP). 1. In all KD groups the depletion treatment significantly reduced both potassium plasma concentration (PK) and urinary potassium excretion while it increased basal PRA; the basal urinary aldosterone excretion was not significantly different from normokalemic controls. In the KD3 vs KD1 group the P kappa value was significantly lower. 2. In both KD2 and KD3 groups as compared to the N group, several hypokalemic-like renal dysfunctions--absent in the KD1 group--occurred. Particularly, in the KD2 + KD3 vs N group the renal ability in both urine diluting (water load) and concentrating (LVP infusion) was significantly impaired.(ABSTRACT TRUNCATED AT 250 WORDS)
Agnoli
G C
GC
Cattedra di Medicina Interna, Università di Bologna, Italy.
Borgatti
R
R
Cacciari
M
M
Garutti
C
C
Ikonomu
E
E
Lenzi
P
P
Marinelli
M
M
D015121:6-Ketoprostaglandin F1 alpha / Q000652:urine; D000328:Adult; D000450:Aldosterone / Q000652:urine; D001794:Blood Pressure; D015232:Dinoprostone / Q000652:urine; D004231:Diuresis; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007008:Hypokalemia / Q000503:physiopathology*; D007668:Kidney / Q000503:physiopathology*; D008875:Middle Aged; D009318:Natriuresis; D011141:Polyuria / Q000652:urine; D011188:Potassium / Q000652:urine; D017419:Potassium, Dietary / Q000008:administration & dosage; D011453:Prostaglandins / Q000502:physiology*; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000502:physiology*; D013929:Thromboxane B2 / Q000652:urine
D017419:Potassium, Dietary; D011453:Prostaglandins; D000450:Aldosterone; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D012083:Renin; D015232:Dinoprostone; D011188:Potassium