Regulation of renal Na -K-ATPase in the rat: role of increased potassium transport

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · Am. J. Physiol.; (United States)

OSTI ID:6411794

Mujais, S K; Chekal, M A; Hayslett, J P; Katz, A I

The purpose of this study was to characterize the alterations in collecting tubule Na -K -ATPase activity produced by sustained increments in dietary potassium in the rat and to evaluate the role of aldosterone in their generation. In adrenal-intact animals, feeding a high-potassium diet or administration of a high physiological dose of aldosterone, which simulates the delivery rate of this hormone during potassium loading, caused marked increments in Na -K -ATPase activity in the cortical collecting tubule (CCT) but had no effect on the enzyme in the inner stripe of the medullary collecting tubule (MCT). A significant increase in enzyme activity was also observed after smaller dietary potassium increments and after 4 days of dietary potassium load. In adrenalectomized rats provided with physiological replacement doses of corticosterone and aldosterone, Na -K -ATPase activity in both CCT and MCT was similar to that of adrenal-intact controls but remained unchanged after 7 days on the potassium-enriched (10-fold) diet. In contrast, adrenalectomized animals receiving the high physiological dose of aldosterone displayed an increase in Na -K -ATPase activity of CCT comparable with that of adrenal-intact animals, whereas the enzyme activity in the MCT was unaffected. In conclusion, 1) following chronic potassium loading Na -K -ATPase activity increases significantly in the CCT with no change in its activity in the inner stripe of the MCT; 2) this increase in enzyme activity occurs in a time-dependent fashion and in proportion to the potassium load; and 3) the stimulation of Na -K -ATPase activity in adrenal-replaced rats is facilitated by augmented levels of aldosterone, such as those actually observed in adrenal-intact rats subjected to chronic potassium loading.

• Research Organization: Univ. of Chicago Pritzker School of Medicine, IL
• OSTI ID: 6411794
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 251:2; ISSN AJPHA
• Country of Publication: United States
• Language: English

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551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ADRENAL HORMONES
ALDEHYDES
ALDOSTERONE
ALKALI METAL COMPOUNDS
ANIMALS
ATP
ATP-ASE
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
BODY
CHEMISTRY
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
HORMONES
HYDROLASES
HYDROXY COMPOUNDS
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
KIDNEYS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MINERALOCORTICOIDS
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOSPHOHYDROLASES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
POTASSIUM COMPOUNDS
PREGNANES
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
RATS
RODENTS
SODIUM COMPOUNDS
STEROID HORMONES
STEROIDS
TRACER TECHNIQUES
TUBULES
VERTEBRATES