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This study was designed to investigate the impact of representative antihypertensive drugs of 5 classes on the sexual function in male spontaneously hypertensive rats (SHR) at doses that achieved similar blood pressure (BP) reduction. The experiment was performed in 6 groups of male SHR. The dose are 20 μg/kg/day for clonidine, 3 mg/kg/day for enalapril, 20 mg/kg/day for atenolol, 2 mg/kg/day for amlodipine, and 10 mg/kg/day for dihydrochlorothiazide. SHR were treated for 3 months, and then the penile erection and sexual behavior were detected. After BP recording, SHR were killed to evaluate the organ-damage, weight of accessory sex organs and levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone in serum. Five drugs had the similar efficacy on BP reduction. All drugs except of enalapril, significantly prolonged the mount latency, and decreased the mount frequency (P<0.05). Clonidine also reduced the conception rate (45% vs. 80% in control group, P<0.05). Amlodipine and dihydrochlorothiazide significantly increased the testosterone level (0.79±0.30, 0.80±0.34 vs. 0.49±0.20 in control group, unit: ng/dl, P<0.05). Enalapril, atenolol and amlodipine also significantly decreased the BP variability (systolic, 8.2±2.5, 7.6±1.8, 8.9±2.0 vs. 12.2±3.8 in control group, unit: mm Hg). All these drugs significantly decreased the organ-damage (P<0.05). In conclusion, long-term treatment with 5 common antihypertensive drugs possessed obvious organ protection in SHR. Clonidine, atenolol, amlodipine and dihydrochlorothiazide, but not enalapril, impair sexual function.

This study was designed to evaluate the synergism of two couples of antihypertensive drugs (amlodipine + telmisartan and amlodipine + candesartan) on blood pressure reduction in vivo by both SynergyFinder 3.0 and probability sum test. Spontaneously hypertensive rats were treated with intragastric administration of amlodipine (0.5, 1, 2, and 4 mg/kg), telmisartan (4, 8, and 16 mg/kg), candesartan (1, 2, and 4 mg/kg), nine combinations for amlodipine and telmisartan, and nine combinations for amlodipine and candesartan. The control rats were treated by 0.5% carboxymethylcellulose sodium. Blood pressure was recorded continuously up to 6 h after administration. Both SynergyFinder 3.0 and the probability sum test were used to evaluate the synergistic action. The synergisms calculated by SynergyFinder 3.0 are consistent with the probability sum test both in two different combinations. There is an obviously synergistic interaction between amlodipine and telmisartan or candesartan. The combinations of amlodipine and telmisartan (2 + 4 and 1 + 4 mg/kg) and amlodipine and candesartan (0.5 + 4 and 2 + 1 mg/kg) might exert an optimum synergism against hypertension. Compared with the probability sum test, SynergyFinder 3.0 is more stable and reliable to analyze the synergism. [ABSTRACT FROM AUTHOR]

Summary: Aims: It is unclear whether the impaired BRS plays a key role in the incidence of cardiovascular diseases. The molecular mechanism of impaired BRS remains to be fully elucidated. We hypothesized that selection of rats based on deficient and normal intrinsic BRS would yield models that reflect cardiovascular diseases risk. Methods and Results: Twenty generations of selection produced arterial baroreflex low rats and normal rats that differed in BRS by about 2.5‐fold change. Metabolic syndrome (including hypertension, overweight, hyperlipemia, and hyperglycemia) emerged in ABR‐DRs. Although ABR‐DRs consumed less food, they gained significantly more body weight. Conclusion: Our study demonstrated that intrinsic low BRS induced hypertension and metabolic disorder. Restoration of impaired BRS might be a potent target of therapeutic intervention in metabolic syndrome. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the possible synergism of amlodipine and candesartan on the reduction of blood pressure (BP) in hypertensive rats. The end organ protection was also observed. In acute experiment, spontaneously hypertensive rats (SHRs) were treated with intragastric administration of amlodipine (0.5, 1, 2, 3 mg/kg), candesartan (1, 2, 3, 4, 6, 8 mg/kg), and 14 different combinations to find the possible ratio of synergistic interaction. In two kidneys, one clip (2K1C) rats, the effects of amlodipine (1 mg/kg), canderastan (2 mg/kg) and their combination on BP reduction were also observed. In chronic study, SHRs were treated with amlodipine (1 mg/kg), candesartan (2 mg/kg), and their combination for 5 months. Organ damage evaluation was performed after BP recording. The probability sum test (q test) was used to evaluate the synergistic action. There is a synergistic interaction between amlodipine and candesartan on BP reduction. The optimal dose ratio is 1:2. The synergistic effect was also confirmed by 2K1C hypertensive rats. In chronic study, this combination (1:2) possessed an obvious synergism on the reduction of BP and BP variability (BPV) and protection on end organs. Multiple regression analysis showed that heart and aortic hypertrophy indexes and glomerular damage parameters were positively related to BP and BPV. In conclusion, combination of amlodipine and candesartan exhibited a potent antihypertensive effect and possessed an obvious synergism on BP reduction and organ protection in hypertension. The optimal proportion was 1:2. BP and BPV reduction may both importantly contribute to end organ protection. [ABSTRACT FROM AUTHOR]