Chronic intermittent hypoxia (CIH), a preclinical model of hypoxemia associated with sleep apnea, causes hypertension associated with increased sympathetic activity linked to arterial chemoreflex and renin-angiotensin system activation. In some models of CIH, ovarian hormones have a protective effect against the change in blood pressure. We tested the effects of CIH and ovariectomy (OVX) on blood pressure and ΔFosB expression in female Sprague-Dawley rats. We hypothesized that CIH and OVX would increase ΔFosB in central autonomic regions associated with increases in blood pressure. Intact (INT) and OVX adult female Sprague-Dawley rats were exposed to 7 days of CIH only during the light (sleep) phase or continuous normoxia (CON). Mean arterial pressure (MAP) was continuously monitored by radiotelemetry. Rats were anesthetized with Inactin and euthanized, and brains were collected and processed for immunohistochemistry. CIH increased MAP relative to CON during the light phase, regardless of gonadal status. During the dark (active) phase, an increase in MAP was observed in OVX but not INT rats, irrespective of CIH. CIH significantly increased ΔFosB immunoreactive cells in the caudal nucleus of the solitary tract, A5 region, and rostral ventrolateral medulla regardless of OVX. Independent of CIH, OVX significantly increased ΔFosB immunoreactive cells in the organum vasculosum of the lamina terminalis, median preoptic nucleus, rostral NTS, and the dorsal, medial, and lateral parvocellular subdivisions of the paraventricular nucleus. Our data indicate that CIH and OVX increase blood pressure independently and exert region-specific effects on ΔFosB immunoreactivity in central autonomic regions.

Keywords: Chronic intermittent hypoxia; Delta FosB; central autonomic; estrogen; hypertension; ovariectomy; sex hormone; sympathetic activity.

慢性间歇性缺氧（CIH）是与睡眠呼吸暂停相关的低氧血症的一种临床前模型，会导致与交感神经活动增加有关的高血压，这种增加与动脉化学反射和肾素-血管紧张素系统激活相关。在某些CIH模型中，卵巢激素具有防止血压变化的保护作用。我们测试了CIH和卵巢切除（OVX）对雌性Sprague-Dawley大鼠血压及ΔFosB表达的影响。我们认为，CIH和OVX会增加与血压升高相关的中枢自主神经区域中的ΔFosB。成年未绝育（INT）和卵巢切除的雌性Sprague-Dawley大鼠接受了7天仅在光照（睡眠）阶段进行的CIH处理或持续正常氧环境（CON）。通过放射遥测法连续监测平均动脉压（MAP）。将大鼠麻醉并安乐死后，收集大脑并进行免疫组化处理。与对照相比，在光照期间，无论卵巢状况如何，CIH都会增加MAP。在暗光（活跃）阶段，无论是INT还是经历CIH的大鼠，只有OVX大鼠观察到MAP升高。CIH显著增加了尾端孤束核、A5区和头侧外侧延髓中ΔFosB免疫阳性细胞的数量，这与是否进行卵巢切除无关。在没有受到CIH影响的情况下，OVX显著增加了一条血管器官的终末 lamina 终板区域、中线预optic 核、头端孤束核以及室旁核背外侧、内侧和侧小细胞区的ΔFosB免疫阳性细胞的数量。我们的数据显示，CIH和卵巢切除分别独立地增加了血压，并对中枢自主神经区域中的ΔFosB免疫反应性产生了特定区域的影响。

关键词：慢性间歇性缺氧；Delta FosB；中央自主神经系统；雌激素；高血压；卵巢切除；性激素；交感活动。