[Establishment of cardiac remodeling model in FVB/N mice by intraperitoneal injection of isoproterenol].

OBJECTIVE

To explore the feasibility of intraperitoneal injection of isoproterenol (ISO) to induce cardiac remodeling in FVB/N mice.

METHODS

Forty-eight FVB/N mice were divided into back subcutaneous saline group (subcutaneous saline group), intraperitoneal saline group, back subcutaneous ISO group (subcutaneous ISO group), and intraperitoneal ISO group according to the route of administration of saline or ISO. ISO (30 μg/g body weight/day) was given to the subcutaneous ISO group and the intraperitoneal ISO group, twice daily with an interval of 12 hours, for 14 consecutive days. The subcutaneous saline group and the intraperitoneal saline group were injected with an equal volume of saline. The left ventricular end-diastolic posterior wall thickness was measured by echocardiography, and the ratio of heart weight to tibia length was determined. Hematoxylin-eosin staining was used to determine the myocardial fiber diameter. Picric-sirius red staining was used to determine the myocardial collagen deposition area. Quantitative real-time PCR was used to measure the mRNA expression of collagen I.

RESULTS

Compared with the subcutaneous ISO, subcutaneous saline, and intraperitoneal saline groups, the intraperitoneal ISO group had increased sizes of the cardiac cavity and the heart. Compared with the subcutaneous saline and intraperitoneal saline groups, the subcutaneous ISO group showed no significant changes in the gross morphology of the cardiac cavity and the heart. The intraperitoneal ISO group showed significant increases in the ratio of heart weight to tibia length, myocardial fiber diameter, left ventricular end-diastolic posterior wall thickness, myocardial collagen area percentage, and the mRNA expression of collagen I compared with the subcutaneous ISO, subcutaneous saline, and intraperitoneal saline groups (P<0.01). There were no significant differences in the above five indices between the subcutaneous ISO group and the subcutaneous saline and intraperitoneal saline groups (P>0.05). No significant difference in the mortality rate was found between the subcutaneous ISO and intraperitoneal ISO groups (P>0.05).

CONCLUSIONS

Intraperitoneal injection of ISO can induce cardiac hypertrophy and fibrosis in FVB/N mice.