Myo-inositol (MI) is a compatible osmolyte used by cells to compensate for changes in the osmolarity of their surrounding milieu. In kidney, the basolateral SMIT1 and apical SMIT2 proteins are homologous cotransporters responsible for cellular uptake of MI. It has been shown in the MDCK cell line that SMIT1 expression was under the control of the tonicity-sensitive transcription factor TonEBP. We used an MDCK cell line stably transfected with SMIT2 to determine whether variations in external osmolarity could also affect SMIT2 function. Hyperosmotic conditions (+200 mOsm raffinose or NaCl but not urea) generated an increase in SMIT2-specific MI uptake by 3- to 9-fold in a process which required protein synthesis. Using qRT-PCR, we have determined that hyperosmotic conditions augment both the endogenous SMIT1 and the transfected SMIT2 mRNAs. Transport activities for both SMIT1 and SMIT2 exhibited differences in their respective induction profiles for both their sensitivities to raffinose as well as in their time course of induction. Application of MG-132, which inhibits nuclear translocation of TonEBP, showed that the effect of osmolarity on transfected SMIT2 was unrelated to TonEBP, unlike the effect observed with SMIT1. Inhibition studies involving the hyperosmolarity-related MAPK suggested that p38 and JNK play a role in the induction of SMIT2. Further studies have shown that hyperosmolarity also upregulates another transfected transporter (Na⁺/glucose) as well as several endogenously expressed transport systems. This study shows that hyperosmolarity can stimulate transport in a TonEBP-independent manner by increasing the amount of mRNA derived from an exogenous DNA segment.