[en] We studied the hydrostatic pressure effect on the temperature dependence of resistivity of Pr_0.7-xLa_xCa_0.3MnO₃, Pr_0.7Ca_0.3-ySr_yMnO₃ and Pr_0.66Ca_0.34-zSr_zMnO₃ compounds, with different metal-insulator transition temperatures T_MI. The pressure derivative dT_MI/dP depends linearly on T_MI^-1. For the compounds Pr_0.66Ca_0.34-zSr_zMnO₃ it achieves a record value of 30 K/kbar. In contrast, the pressure effect on the charge ordering temperature is very weak. The analysis of changes in T_MI and structural parameters at chemical and at external pressure shows that to achieve a qualitative agreement, a contribution of e-ph interactions and/or 'Jahn-Teller' effects have to be taken into account