Phelps C P, Krieg R J, Sawyer C H
Brain Res. 1976 Jan 16;101(2):239-49. doi: 10.1016/0006-8993(76)90266-3.
Plasma LH levels in adult female rats were studied by radioimmunoassay 6 weeks after making frontal cuts (FC) at the optic chiasm with Halász knives of various sizes. Cuts made with a small knife (radius 1.3 mm) permitted a spontaneous rise in plasma LH during proestrus from a mean of 96 +/- 25 ng/ml at 14:00 h to 545 +/- 207 ng/ml at 18:00 h in 13 rats. Seven of the latter, with a mean plasma LH of 967 +/- 281 ng/ml at 18:00 h exhibited tubal ova at hemicastration (hemi-ovx) the following morning. In a similar experiment 6 FC females lesioned with a 1.5 mm knife had plasma LH levels of 53 +/- 7 ng/ml at 14:00 h, but showed neither detectable changes at 2 h intervals through 20:00 h nor ovulation at hemi-ovx. Similar results were obtained in 13 rats deafferented with a 2.0 mm knife. Nine weeks after FC and 3 weeks following hemi-ovx all animals were given pentobarbital (32 mg/kg i.p.) at 13:30 h and stimulated bilaterally in the medial preoptic area (MPO) passing 20 muA anodal DC X 60 sec through concentric bipolar steel electrodes placed 0.8 mm from the midline. All 3 groups of FC animals showed increases in plasma LH to comparable levels (range: 197 +/- 45-357 +/- 156 ng/ml) 1 h after stimulation. Electrochemical stimulation sites extended lateral to the cut locations on at least one side in all animals. The results of these studies suggest that chronically (9 week) deafferented female rats have the capacity to release pituitary LH in response to MPO electrochemical stimulation in spite of retrochiasmatic deafferentation, but that the ovaries of the persistent estrus rat are unresponsive to these amounts of circulating LH.
用不同尺寸的哈拉斯小刀在成年雌性大鼠的视交叉处进行额部切割（FC）6周后，通过放射免疫分析法研究其血浆促黄体生成素（LH）水平。用小刀（半径1.3毫米）进行的切割使得13只大鼠在发情前期血浆LH自发升高，从14:00时的平均96±25纳克/毫升升至18:00时的545±207纳克/毫升。其中7只大鼠在18:00时血浆LH平均为967±281纳克/毫升，次日早晨半侧卵巢切除（半侧卵巢摘除）时输卵管中有卵子。在一项类似实验中，6只接受1.5毫米小刀损伤的FC雌性大鼠在14:00时血浆LH水平为53±7纳克/毫升，但在至20:00时的2小时间隔内未显示可检测到的变化，半侧卵巢摘除时也未排卵。用2.0毫米小刀去传入神经的13只大鼠也得到了类似结果。FC后9周和半侧卵巢摘除后3周，所有动物于13:30时腹腔注射戊巴比妥（32毫克/千克），并通过置于距中线0.8毫米处的同心双极钢电极，以20微安阳极直流电刺激双侧内侧视前区（MPO）60秒。所有3组FC动物在刺激后1小时血浆LH均升高至相当水平（范围：197±45 - 357±156纳克/毫升）。所有动物的电化学刺激部位至少在一侧延伸至切割位置的外侧。这些研究结果表明，尽管视交叉后去传入神经，但长期（9周）去传入神经的雌性大鼠仍有能力响应MPO电化学刺激释放垂体LH，不过持续发情大鼠的卵巢对这些循环LH量无反应。
