Abstract：
The mammalian dive reflex, characterized by bradycardia and peripheral vasoconstriction, occurs in all mammals, including humans, in response to apnea. However, the dive reflex to a single, maximal, dry, dynamic apnea (DYN), and how it compares to a time-matched exercise control trial (EX) or dry static apnea (SA), has not been studied. We examined the hypotheses that, compared to EX and SA, the magnitude of the (a) cardiovascular response and (b) hematological response to DYN would be greater. Cardiovascular parameters (heart rate [HR], systolic [SBP], diastolic [DBP], and mean arterial [MAP] blood pressure) were continuously collected in twenty-three (F=6) moderate and elite freedivers, first during a maximal DYN, then during a time-matched SA and EX on a swimming ergometer in randomized order. Venous blood draws were made prior to and following each trial. The change in calculated oxygen saturation (DYN:-17±13%, EX:-2±1%, ΔSA:-2±1%;P<0.05, all comparisons) was greater during DYN compared to EX and SA. During DYN, ΔSBP (DYN:104±31mmHg, EX:38±23mmHg, SA:20±11mmHg), ΔDBP (DYN:45±12mmHg, EX:14±10mmHg, SA:15±8mmHg) and ΔMAP (DYN:65±17mmHg EX:22±13mmHg, SA:16±9mmHg) were increased compared to EX and SA, while ΔHR was greater during EX (DYN:-24±23bpm, EX:33±13bpm, SA:-1±10bpm) than either DYN or SA (P<0.0001, all comparisons). Females had greater pressor response to EX (ΔSBP:59±30mmHg, ΔDBP:24±14mmHg, ΔMAP:35±8mmHg) than males (ΔSBP:31±15mmHg, ΔDBP:11±6mmHg, ΔMAP:18±8mmHg; P<0.01, all comparisons). Together, these data indicate that DYN elicits a distinct, exaggerated cardiovascular response compared to EX or SA alone.
摘要：
哺乳动物的潜水反射,以心动过缓和外周血管收缩为特征，发生在所有哺乳动物中，包括人类,对呼吸暂停的反应。然而,对一个人的潜水反射，最大,干,动态呼吸暂停（DYN），以及它如何与时间匹配的运动控制试验（EX）或干静态呼吸暂停（SA）进行比较，没有被研究过。我们检查了假设，与EX和SA相比，对DYN的(a)心血管反应和(b)血液学反应的幅度将更大。心血管参数（心率[HR]，收缩压[SBP]，舒张压[DBP]，和平均动脉[MAP]血压）连续收集23个（F=6）中度和精英自由潜水者，首先在最大DYN期间，然后在随机顺序的游泳测力计上进行时间匹配的SA和EX。在每次试验之前和之后抽取静脉血液。计算的氧饱和度的变化（DYN：-17±13％，EX:-2±1%,ΔSA：-2±1％；P<0.05，所有比较）在DYN期间与EX和SA相比更大。在DYN期间,ΔSBP(DYN:104±31mmHg,EX:38±23mmHg,SA:20±11mmHg),ΔDBP(DYN:45±12mmHg,EX:14±10mmHg,SA：15±8mmHg）和ΔMAP（DYN：65±17mmHgEX：22±13mmHg，SA：16±9mmHg）与EX和SA相比增加，而ΔHR在EX期间更大(DYN：-24±23bpm，EX:33±13bpm,SA：-1±10bpm）比DYN或SA（P<0.0001，所有比较）。女性对EX的升压反应更大（ΔSBP：59±30mmHg，ΔDBP:24±14mmHg,ΔMAP：35±8mmHg）比男性（ΔSBP：31±15mmHg，ΔDBP:11±6mmHg,ΔMAP：18±8mmHg；P<0.01，所有比较）。一起,这些数据表明DYN引发了一个独特的，与单独的EX或SA相比，心血管反应过度。
