Figure 2

P _EG and ethylene glycol uptake of X. laevis oocytes expressing HsAQP3 or DrAqp3b. (A) P_EG of oocytes expressing different amounts of cRNA (1-40 ng) encoding HsAQP3 or DrAqp3b. Control oocytes were injected with 50 nl of water. The P_EG was measured by swelling measurements during 20 sec in isotonic MBS containing 60 mM of ethylene glycol at pH 7.5. Values are the mean ± SEM of three experiments (n = 8-10 oocytes for each aquaporin). Data with an asterisk at the same cRNA dose are significantly different (Student's t test, p < 0.01). (B) Uptake of radiolabeled ethylene glycol of oocytes injected with 50 nl of water or 5 ng of HsAQP3 or DrAqp3b cRNA. Oocytes were exposed to isotonic MBS containing 1 mM cold ethylene glycol and 5 μM radiolabelled [1,2-³H]ethylene glycol for 1 min. Values (mean ± SEM; n = 8-10 oocytes) with different superscript are significantly (ANOVA, p < 0.01).