Acute Activation of the Renal Betaine/GABA Transporter in Response to a Decrease in Extracellular Calcium

Figure 4

(a) System A amino acid transport was activated 4-fold by Hyp stress (500 mOsm) for 4 h and treatment with hypertonic low Ca²⁺ medium for 2 h produced a further 3.5-fold increase. (b) Activation of BGT1 transport by low Ca²⁺ medium was less marked but still detectable after 1 h under isotonic (Iso) conditions. *Significantly different (𝑃<0.05) from Hyp or Iso controls. Data are mean ± SD from 3-4 separate experiments.

(a)

(b)