OBJECTIVETo examine the negative regulation role of PTEN in isoproterenol-induced cardiac hypertrophy by testing the expression of PTEN mRNA and protein and to explore the effects of captopril (Cap) on PTEN expression.

METHODSTwenty four rats were randomly divided into three groups: control group, ISO group, and ISO+Cap group. The following parameters were examined:body weight (BW), heart weight (HW), left ventricular weight (LVW), left ventricular end-diastolic pressure (LVEDP), left ventricular end-systolic pressure (LVESP) and +/- dp/dt(max). The ratio of HW/BW and LVW/BW was calculated. PTEN mRNA and protein were tested by RT-PCR and Western blot, respectively.

RESULTS(1) Compared with the control group, the ratio of HW/BW and LVW/BW, LVEDP and LVESP were all increased in ISO group and ISO+Cap group (P < 0.05), but +/- dp/dt(max) was decreased (P < 0.05); (2) compared with the ISO group, the ratio of HW/BW and LVW/BW, LVEDP, LVESP were all decreased in ISO+Cap group (P < 0.05), but +/- dp/dt(max) was increased (P < 0.05); (3) compared with the control group, PTEN mRNA and protein were up-regulated in ISO group and ISO+Cap group; (4) compared with the ISO group, PTEN mRNA and protein were up-regulated in ISO+Cap group.

CONCLUSIONSPTEN mRNA and protein are up-regulated in isoproterenol-induced cardiac hypertrophy. Captopril can up-regulate PTEN expression in cardiac hypertrophy. There is a negative regulative mechanism in cardiac hypertrophy process, in which PTEN is probably an endogenous negative regulator of cardiac hypertrophy.