Plasma osmolality predicts extracellular fluid catechol concentrations in the lateral hypothalamus.
Plasma osmolality predicts extracellular fluid catechol concentrations in the lateral hypothalamus.
复制标题
血浆渗透压预测外侧下丘脑细胞外液儿茶酚浓度。
DOI：
10.1111/j.1471-4159.1988.tb01074.x
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发表时间：
1988
影响因子：
4.7
通讯作者：
Freed,CR
中科院分区：
文献类型：
--
作者：
Mason,PA;Durr,JA;Bhaskaran,D;Freed,CR
外侧下丘脑在调节食物和水的摄入方面具有重要作用。我们研究了在血浆渗透压和循环容量的操作过程中，从外侧下丘脑内源性单胺的释放。将在外侧下丘脑中植入碳糊体内电化学（EC）电极的成年雄性Sprague道利大鼠置于72 h禁水时间表中。虽然碳糊EC电极具有固有的模糊信号，其中抗坏血酸的变化可能表现为儿茶酚浓度的变化，但下丘脑外侧的药理学研究表明，电极最有可能测量去甲肾上腺素，也可能测量肾上腺素。在测试当天，用线性扫描伏安法从-0.2 V至+0.4 V以5 mV/s的速率扫描EC电极。半导数信号处理显示儿茶酚和羟基吲哚峰分别在+0.11和+0.23 V。在大鼠饮用蒸馏水、10%蔗糖、5%葡萄糖、0.30%NaCl、0.90%NaCl或10%D-甘露醇之前进行基线记录。为了控制饮水行为，对其他植入脱水大鼠腹腔注射5%葡萄糖、0.30%NaCl或0.90%NaCl。为了分离渗透压和循环容量对EC反应的影响，植入EC电极的水合大鼠皮下注射12% NaCl或腹腔注射35%聚乙二醇。其他大鼠进行禁水和渗透挑战断头和躯干血液收集血浆渗透压和红细胞压积的测量。使用纯合子Brattleboro大鼠进行类似的实验，这些大鼠缺乏精氨酸加压素（AVP），但在大量饮酒的情况下保持正常的血浆渗透压。这些大鼠的使用提供了一种方法来解离单胺的变化相关的AVP释放相关的血浆渗透压的变化。Sprague-道利和Brattleboro大鼠的结果表明，血浆渗透压摩尔浓度高的大鼠中EC儿茶酚信号较低，并且随着饮用或腹腔内液体给药而升高，这是血浆渗透压摩尔浓度下降的直接函数。血浆渗透压摩尔浓度的操作有更大的影响EC儿茶酚信号比循环量的操作。因此，我们得出结论，下丘脑外侧细胞外液儿茶酚浓度的变化线性反映血浆渗透压的变化。
The lateral hypothalamus has an important role in regulating food and water intake. We have investigated the endogenous release of monoamines from the lateral hypothalamus during manipulations of plasma osmolality and circulating volume. Adult male Sprague‐Dawley rats implanted with carbon paste in vivo electrochemical (EC) electrodes in the lateral hypothalamus were placed on a 72‐h water deprivation schedule. Although the carbon paste EC electrode has an intrinsically ambiguous signal in which changes in ascorbic acid may appear as changes in catechol concentrations, pharmacologic studies in lateral hypothalamus indicated that the electrode most likely measured nor‐epinephrine and possibly epinephrine. On the test day, the EC electrodes were scanned with linear sweep voltammetry from ‐0.2 to +0.4 V at a rate of 5 mV/s. Semiderivative signal processing showed catechol and hydroxyindole peaks at +0.11 and +0.23 V, respectively. Baseline recordings were made prior to rats drinking distilled water, 10% sucrose, 5% dextrose, 0.30% NaCl, 0.90% NaCl, or 10%D‐mannitol. To control for the act of drinking, other implanted dehydrated rats were intraperitoneally injected with 5% dextrose, 0.30% NaCl, or 0.90% NaCl. To dissociate the effects of osmolality and circulating volume on the EC response, hydrated rats implanted with EC electrodes were subcutaneously injected with 12% NaCl or intraperitoneally injected with 35% polyethylene glycol. Other rats subjected to water deprivation and osmotic challenges were decapitated and trunk blood was collected for measurements of plasma osmolality and hematocrit. Similar experiments were conducted using homozygous Brattleboro rats which lack arginine vasopressin (AVP) but which preserve normal plasma osmolality with prodigious drinking. The use of these rats provided a way to dissociate monoamine changes related to AVP release from changes related to plasma osmolality. Results in Sprague‐Dawley and Brattleboro rats showed that the EC catechol signal was lower in rats with high plasma osmolality and rose with drinking or intraperitoneal fluid administration as a direct function of the fall in plasma osmolality. Manipulations of plasma osmolality had a greater effect on the EC catechol signal than did manipulations of circulating volume. Thus, we conclude that changes in extracellular fluid catechol concentrations in the lateral hypothalamus linearly reflect changes in plasma osmolality.