Vaginocervical Stimulation Releases Oxytocin within the Spinal Cord in Rats
Vaginocervical Stimulation Releases Oxytocin within the Spinal Cord in Rats
复制标题
阴道宫颈刺激在大鼠脊髓内释放催产素
作者：
G. Sansone;Carolyn A. Gerdes;J. Steinman;J. Winslow;J. Ottenweller;B. Komisaruk;T. Insel
阴道-宫颈刺激（VS）显著提高了8只经尿道麻醉的大鼠脊髓过充液中催产素（OT）的浓度（中位数[四分位数范围]:1.7 [1.00-3.37]pg/ml），高于VS前10-15 min （1.1 [1.01-1.40] pg/ml）。当服用一次VS （n = 8）时，它比基线值增加了55%；当45分钟后第二次给药时（n = 6），它仅比vs前的值增加22%。然后用去卵巢的大鼠皮下注射苯甲酸雌二醇（estradiol benzoate， EB; 10µg/100 g bw） （n = 6）或油驱体（n = 6） 3天，研究雌激素对vs诱导的OT释放的影响。EB治疗显著提高了释放到脊髓过充液的基础OT水平，高于对照水平。在VS发作后5-10分钟内，eb处理的大鼠过充液中的OT浓度明显高于载药处理大鼠。为了排除垂体后腺是这种OT的来源的可能性，我们评估了垂体切除术（HYPOX）对vs诱导的OT释放到脊髓过充液和血浆的影响。缺氧大鼠（n = 5）和正常大鼠（n = 6）脊髓过液中OT浓度分别从VS前的5.8 [4.4 - 6.5]pg/ml增加到VS后立即的7.9 [6.7-10.3]pg/ml，从VS前的4.4 [3.8-5]pg/ml增加到VS后立即的5.1 [4.6-5.7]pg/ml。两组脑脊液中OT的基线水平无显著差异。相比之下，血浆OT水平，虽然在正常组对VS的反应从基线3.42 [2.9-5.34]pg/ml显著升高到7.25 [5.33-15.77]pg/ml，但在HYPOX组对VS没有显著反应（n = 5）。目前的研究结果提供了直接雌激素依赖性的脊髓内OT释放的证据，可能是通过下行的催产素能神经元来响应VS。
Vaginocervical stimulation (VS) significantly elevated the concentration of oxytocin (OT) in spinal cord superfusates of 8 intact urethane-anesthetized rats measured 10–15 min after VS (median [interquartile range]: 1.7 [1.00–3.37] pg/ml) compared to that measured 10–15 min before VS (1.1 [1.01–1.40] pg/ml). When VS was administered once (n = 8), it produced a 55% increase over baseline values; when administered a second time 45 min later (n = 6), it produced only a 22% increase over pre-VS values. The effects of estrogen on the VS-induced release of OT were then investigated using ovariectomized rats that were treated either with estradiol benzoate (EB; 10 µg/100 g bw) (n = 6) or with an oil vehicle (n = 6) subcutaneously for 3 days. The EB treatment significantly elevated the basal levels of OT released into spinal cord superfusates above vehicle control levels. Within 5–10 min after the onset of VS, OT concentrations in the superfusates were significantly higher in EB-treated than in vehicle-treated rats. The vehicle-treated rats did not show a significant elevation in OT concentration following VS. To rule out the possibility that the posterior pituitary gland was the source of this OT, the effect of hypophysectomy (HYPOX) was assessed on the VS-induced release of OT into spinal cord superfusates and plasma. The concentration of OT in spinal cord superfusates of both the HYPOX (n = 5) and intact rats (n = 6) increased significantly from 5.8 [4.4–6.5] pg/ml pre-VS to 7.9 [6.7–10.3] pg/ml immediately after VS, and from 4.4 [3.8–5] pg/ml pre-VS to 5.1 [4.6–5.7] pg/ml immediately after VS, respectively. There was no significant difference in baseline levels of OT in cerebrospinal fluid between the two groups. By contrast, plasma OT levels, while significantly elevated in response to VS from 3.42 [2.9–5.34] pg/ml baseline to 7.25 [5.33–15.77] pg/ml in the intact group, failed to respond significantly to VS in the HYPOX group (n = 5). The present findings provide evidence of a direct estrogen-dependent release of OT within the spinal cord in response to VS, presumably via descending oxytocinergic neurons.
DOI：
10.1073/pnas.95.6.3281
发表时间：
1998-03-17
影响因子：
11.1
作者：
Alves, SE;Lopez, V;Weiland, NG
通讯作者：
Weiland, NG
影响因子：
56.9
作者：
PEDERSEN, CA;ASCHER, JA;PRANGE, AJ
通讯作者：
PRANGE, AJ