Exercise-induced cardiac fatigue in low and normal birth weight young black adults.

The objective of the study was to compare the change in diastolic function, E/A ratio, in response to prolonged exercise in low birth weight and normal birth weight individuals. Using a case-control study design, 23 students of the University of Zimbabwe College of Health Sciences who had neonatal clinic cards as proof of birth weight were recruited into the study. Measurements of diastolic function, E/A ratio, were obtained using an echocardiogram before and after 75 minutes of exercise. Among the cohort, seven had low birth weight - <2500 g, three female patients and four male patients - and 16 had normal birth weight - six female patients and 10 male patients). The mean age was 20.7±3.3 years. After prolonged exercise for 75 minutes of running on a treadmill, decreases in diastolic function, E/A ratio, were significantly greater in low birth weight than in normal birth weight individuals (0.48±0.27 versus 0.19±0.18 p<0.05, respectively). There was a significant association between low birth weight and exercise-induced cardiac fatigue (the χ2 test p<0.05, odds ratio 4.64, 95% confidence interval 1.19-18.1). We conclude that low birth weight is associated with exercise-induced diastolic dysfunction in young adults.

Cardiovascular effects of Boophone disticha aqueous ethanolic extract on early maternally separated BALB/C mice.

ETHNOPHARMACOLOGICAL RELEVANCE: There are a number of reports from traditional medical practice in Zimbabwe and neighboring countries and few in vitro studies suggesting an effect with extracts of Boophone disticha in some forms of anxiety disorder. AIM OF THE STUDY: In order to validate the use of Boophone disticha in treatment of anxiety, this study was set to determine the effects of the plant extracts on blood pressure (BP) and heart rate (HR) in adult BALB/c mice subjected to repeated early maternal separation (MS) stress. MATERIALS AND METHODS: To test whether early life stress increases anxiety in mice, non-invasive tail cuff method was used to examine the autonomic nervous system activity by assessing cardiovascular reactivity and response to acute mixing stress (AMS) and restraint stress (RS) in adult mice subjected to early postnatal stress as compared to control. AMS-induced cardiovascular response was then evaluated in adult MS mice treated with Boophone disticha as compared to vehicle and diazepam. RESULTS: Comparisons of the BP and HR measurements indicated that MS significantly reduced AMS-induced HR responses in BALB/c mice when compared with control. Boophone disticha treatment significantly reduced AMS-induced BP response in BALB/c MS mice as compared to vehicle and diazepam treatments. CONCLUSIONS: Our findings demonstrate for the first time that postnatal stress can induce short-term changes in the sensitivity of the cardiovascular system to subsequent stress which can be reduced by treatment with a freeze dried aqueous ethanolic extract of Boophone disticha.