Developmental maturation of calcium transport by rat brush border membrane vesicles

Fayez K Ghishan, Noushin Arab

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The developmental aspects of calcium transport across the intestinal brush membrane vesicles was studied utilizing a millipore filtration technique. Calcium transport represented uptake into the intravesicular space as evidenced by osmolality studies, calcium release by the calcium ionophore A23187, and temperature dependency. Calcium transport in both suckling and adolescent rats appears to occur by a saturable mechanism. Calcium uptake was similar in the presence of sodium and potassium gradients, but decreased in the presence of choline gradient. The imposition of negative membrane potential did not enhance calcium uptake compared to voltage clamp conditions indicating an electroneutral process. The initial rate of calcium uptake was linear up to 15 s. Kinetic analysis of calcium uptake at 7 s showed lower Vm,% and lower Km in suckling rats compared to adolescent rats. These studies are the first to demonstrate the maturational aspects of calcium entry at the brush border level and are consistent with our previous kinetic studies utilizing whole tissue.

Original languageEnglish (US)
Pages (from-to)173-176
Number of pages4
JournalPediatric Research
Volume22
Issue number2
StatePublished - 1987
Externally publishedYes

Fingerprint

Microvilli
Calcium
Membranes
Calcium Ionophores
Calcimycin
Choline
Membrane Potentials
Osmolar Concentration
Potassium
Sodium
Temperature

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Cite this

Developmental maturation of calcium transport by rat brush border membrane vesicles. / Ghishan, Fayez K; Arab, Noushin.

In: Pediatric Research, Vol. 22, No. 2, 1987, p. 173-176.

Research output: Contribution to journalArticle

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