Publications (2)7.58 Total impact
-
Article: Cardiac neural regulation oscillates with the estrous cycle in freely moving female rats: the role of endogenous estrogens.
[show abstract] [hide abstract]
ABSTRACT: Both estrogens levels and sleep/wakefulness states have been separately reported to affect cardiac autonomic regulation. In this study, we examined the integrated effects of the estrous and sleep cycles on cardiac autonomic activity in freely moving adult female rats. Cardiac autonomic activities were measured by analyzing the power spectrum of heart rate variability. High-frequency power (HF) and low-frequency power to HF ratio are closely correlated with cardiac parasympathetic and sympathetic activity, respectively. Ten days after electrodes were implanted, electroencephalogram, electromyogram, and electrocardiogram were recorded 6 h daily for 12 consecutive days to cover at least two estrous cycles. Estrous-cycle stages were determined using vaginal smears. Sleep cycle-related heart rate variability parameter oscillations were seen in all rats. However, the estrous cyclicity and estrous-cycle-related changes were only observed in the control rats and not in ovariectomized or the estrogen receptor antagonist, tamoxifen, treatment rats. A significantly higher HF was observed in estrous rats compared with diestrous rats or ovariectomized rats no matter whether the rats were asleep or awake. However, a significantly low-frequency power to HF ratio was only observed in quiet sleep (QS) during estrus. All these differences disappeared after treatment with tamoxifen. Our results suggest that estrous-cycle-related changes in cardiac neural regulations can be mainly attributed to endogenous estrogens, and these effects are most obviously manifest during QS. Estrous rats during QS would be equivalent to the late follicular phase of the women menstrual cycle and involve strong vagal tone but weak sympathetic activity.Endocrinology 06/2010; 151(6):2613-21. · 4.46 Impact Factor -
Article: Combined cardiac sympathetic excitation and vagal impairment in patients with non-organic erectile dysfunction.
[show abstract] [hide abstract]
ABSTRACT: Patients with non-organic erectile dysfunction (ED) frequently present with syndromes involving systemic sympathovagal dysfunction. The linkage of ED to cardiac autonomic regulation is not well understood. Forty-four men with non-organic ED and 38 healthy age-matched control subjects with ages ranging from 40 years to 69 years were recruited. These two groups were divided into three distinct age categories at 10-year intervals. Patients were divided into three different severity categories, among whom 35 patients received a two-month oral treatment of trazodone. Power spectral analysis of successive R-R intervals (RR) was performed to evaluate the variance (variance of RR-interval values), the high-frequency power (HF), and the ratio of low-frequency power to HF (LF/HF) of their heart rate variability (HRV). Patients exhibited a significantly lower variance and HF, but a higher LF/HF compared to the control group across all age categories. The changes in variance and HF were severity dependent. In addition, all the HRV parameters of the patients with a satisfactory response after treatment have significantly improved. The results indicate that patients with non-organic ED had significant cardiac sympathetic hyperactivity and severity-dependent cardiac vagal impairment. Non-organic ED may be accompanied by an abnormality in cardiac autonomic regulation.Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 01/2009; 120(2):348-52. · 3.12 Impact Factor
