Modulatory effect of thyroid hormones on uptake of phosphate and other solutes across luminal brush border membrane of kidney cortex

Journal Article · Sat Jun 01 00:00:00 EDT 1985 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-116-6-2438· OSTI ID:5127075

Yusufi, A N; Murayama, N; Keller, M J; Dousa, T P

The mechanism whereby thyroid hormones modulate the transport properties of luminal brush border membrane (BBM) of renal proximal tubules was studied in thyroparathyroidectomized rats. Administration of both T4 and T3 increased BBM capacity for Na/sup +/ gradient-dependent uptake of phosphate (P /sub i/) by BBM vesicles (BBMV). This effect of thyroid hormones was present in thyroparathyroidectomized and hypophysectomized rats, and it was not blocked by a saturating dose of propranolol. The stimulatory effect of T3 and T4 on BBM transport of P /sub i/ was dose dependent in the range of 5.2-520 nmol/100 g BW. Pretreatment of rats with inhibitors of 5'-monodeiodinase (5'-DI), iopanoic acid or ipodate, prevented the increase in serum T3 in rats injected with T4, but it did not diminish the increase in BBM transport of P /sub i/. Administration of iopanoic acid and ipodate also prevented a 5-fold increase in 5'-DI activity in renal cortical tissue elicited by T4 administration. Treatment with T3 resulted in an increase of Pi transport across BBM from kidneys of rats subjected to dietary P /sub i/ deprivation due either to total fasting or to feeding of a low P /sub i/ diet. Further, T3 administration enhanced amiloride-sensitive Na+-H+ countertransport across BBM, but the uptake of /sup 22/Na+ by BBMV in the absence of pH gradient was not changed. The Na+ gradient-dependent uptake of L-(/sup 3/H)proline by BBMV was slightly decreased, but the uptake of (/sup 14/C)citrate was not changed in response to T3. Administration of T3 increased P /sub i/ transport in BBMV prepared from juxtamedullary cortex, but not in BBMV from superficial cortex. Conversely, the rate of Na+-H+ countertransport was enhanced, and the enzymatic activity of alkaline phosphatase was decreased in BBMV from superficial cortex; no changes in these parameters were found in BBMV from juxtamedullary cortex.

• OSTI ID: 5127075
• Journal Information: Endocrinology; (United States), Vol. 6
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PHOSPHATES
MEMBRANE TRANSPORT
SODIUM 22
THYROID HORMONES
BIOLOGICAL EFFECTS
ALKALINE PHOSPHATASE
CARBON 14 COMPOUNDS
ENZYME ACTIVITY
ENZYME INHIBITORS
GLOMERULI
HYDROGEN IONS 1 PLUS
HYPOPHYSECTOMY
IOPAMIDOL
KIDNEYS
PARATHYROID GLANDS
PROLINE
RATS
SYMPATHOLYTICS
THYROIDECTOMY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALI METAL ISOTOPES
AMINES
AMINO ACIDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZOLES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
CONTRAST MEDIA
DRUGS
ENDOCRINE GLANDS
ENZYMES
ESTERASES
GLANDS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROGEN IONS
HYDROLASES
IONS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MEDICINE
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PEPTIDE HORMONES
PHOSPHATASES
PHOSPHORUS COMPOUNDS
PYRROLES
PYRROLIDINES
RADIOISOTOPES
RODENTS
SODIUM ISOTOPES
SURGERY
VERTEBRATES
YEARS LIVING RADIOISOTOPES
550501* - Metabolism- Tracer Techniques