The antihypertensive effect of irbesartan in spontaneously hypertensive rats is associated with improvement of the leptin–adiponectin imbalance

Objective: This study aimed to investigate whether the antihypertensive effect of irbesartan (IRB) in spontaneously hypertensive rats (SHR) was achieved through improvement of insulin resistance and adjustment of the LPN–APN imbalance.Methods:SHR rats were divided into SHAM, SHR-A and SHR-I group(8 per group). Homologous Wistar–Kyoto (WKY) rats were used as control group (WKY).The SHR-I group received 30 mg/kg/d IRB, the SHR-A group received 2.5 mg/kg AML. After 8 weeks, systolic blood pressure (SBP) was measured. The concentrations of blood glucose, insulin, LPN and APN were detected. Rat epididymal adipose tissues were collected to analyze the mRNA expression levels ofepididymal LPN and APN using reverse transcription–polymerase chain reaction. In addition, the LPN/APN ratio was calculated. Results:SBP, homeostasis model assessment of insulin resistance (HOMA-IR), LPN concentration, adipose LPN mRNA expression level, and the LPN/APN ratio increased (P<0.05) and APN concentration and adipose APN mRNA expression level decreased (P<0.05) in SHR rats.IRB decreased SBP, HOMA-IR, serum LPN, adipose LPN mRNA expression, and the LPN/APN ratio and increased serum APN and adipose APN mRNA expression. Conclusion: The antihypertensive effect of IRB in SHR rats was associated with its improvement of insulin resistance and correction of the LPN–APN imbalance. Abbreviations: ANOVA, one-way analysis of variance; SHR, Spontaneously hypertensive rats; WKY, Wistar kyoto rats; IRB, Irbesartan; AML, Amlodipine; LPN, Leptin; APN, Adiponectin; Ang-II, AngiotensinⅡ; HOMA-IR, Homoeostasis model assessment-insulin resistance; SBP, Systolic blood pressure; RT-PCR, Reverse transcription polymerase chain reaction; ARB, AngiotensinⅡreceptor blocker