ABSTRACT
Objectives: Frequency-domain analysis of heart rate variability [HRV] is an effective tool to evaluate autonomic balance. This study aimed to investigate gender differences in HRV among individuals undergoing regular resistance training
Methods: This preliminary cross-sectional study was conducted from April to September 2016 in Joao Pessoa, Paraiba, Brazil. The low-frequency [LF], high-frequency [HF] and LF/HF ratio components of HRV spectral analysis were analysed among 22 men and 27 women undergoing regular resistance training
Results: Among the male participants, the LF component was significantly increased compared to females in both the supine [1,171 +/- 192 versus 545 +/- 74 ms[2]; P = 0.0067] and upright [1,824 +/- 260 versus 738 +/- 133; P = 0.0011] positions. The LF/HF ratio was also significantly increased in both positions among male participants [P <0.0500 each]
Conclusion: These preliminary data suggest a possible gender difference in the HRV of individuals undergoing resistance training
ABSTRACT
Blood-borne angiotensin-II (Ang-II) has profound effects in the brain. We tested the hypothesis that Ang-II-dependent hypertension involves differential Ang-II type I (AT1) receptors expression in the subfornical organ (SFO) and the rostral ventrolateral medulla (RVLM). Male Wistar rats were implanted with 14-day osmotic minipump filled with Ang-II (150 ng/kg/min) or saline. AT1 receptor mRNA levels were detected in the SFO and RVLM by reverse transcription-polymerase chain reaction (RT-PCR). Ang-II caused hypertension (134 +/- 10 mmHg vs. 98 +/- 9 mmHg, n = 9, p < 0.05). RT-PCR revealed that Ang-II infusion induced increased AT1 receptor mRNA levels in RVLM and decreased in SFO. Our data suggest that Ang-II-induced hypertension involves differential expression of brain AT1 receptors.