On the fate of dopamine-beta-hydroxylase after release from the pheripheral sympathetic nerves in the cat.
On the fate of dopamine-beta-hydroxylase after release from the pheripheral sympathetic nerves in the cat.
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关于猫外周交感神经释放后多巴胺-β-羟化酶的命运。
DOI：
10.1111/j.1748-1716.1974.tb05783.x
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
W. Hellström
中科院分区：
文献类型：
--
作者：
S. Ross;H. Eriksson;W. Hellström
多巴胺- b -羟化酶（DBH），催化多巴胺羟化为去甲肾上腺素，位于交感神经和肾上腺髓质的染色质细胞的储存囊泡中，与去甲肾上腺素一起从这两个部位释放（Geffen et al. 1969, de Potter et al. 1969, Vivelti et al. 1969）。由于血清中含有相当数量的DBH活性，因此有人认为，从交感神经和胆色蛋白细胞释放的酶到达血液循环（Weinshilboum和Axelrod 1971 a， b）。DBH是一种分子量约为290,000 （Friedm）的大分子。b和Kaufmann 1965)，因此只能缓慢地从组织液中通过，并在组织液中直接释放到血液循环中。淋巴系统似乎是DBH进入血液的另一种途径。最近报道了DBH在人类淋巴中的发生（Aberg et al. 1974）。这一观察本身并不能证明淋巴中的DBH来自交感神经，因为血浆蛋白是淋巴的正常成分。为了研究淋巴中的DBH是否来源于交感神经，我们测定了麻醉猫对交感神经系统的刺激对淋巴和血浆中DBH活性的影响。使用神经节刺激剂二甲基苯基哌嗪碘（DMPP）对交感神经系统进行k大剂量刺激。6只猫，体重2.54磅。实验采用戊巴比酮钠麻醉，麻醉剂量为0 kg。胸导管在横膈膜下方插管。在冰冷冻管中收集淋巴液30分钟。测定淋巴流量1，；测量淋巴的体积。DMPP以0.1 mg/kg的剂量连续注射3次。#每隔10分钟注入股静脉。第一次注射在淋巴收集开始1小时后进行。每30分钟取一次股静脉血样。在股动脉测量血压。根据Molinoff et aJ的方法测定血浆和淋巴中的DBH活性。（1971）使用酪胺作为底物，修改DBH测定在pH 5.2下进行（Weinshilbouin et 01）。1973)。血浆和淋巴在检测前用8体积蒸馏水稀释。血浆和淋巴中DBH测定的最佳硫酸铜浓度为7 × 10-eM。DBH活性在正常章鱼胺中表达，每20分钟孵育一次。在cjf30min期间收集的淋巴中DBH的数量也被估计。
The enzyme dopamine-B-hydroxylase (DBH), which catalyzes the hydroxylation of dopamine to noradrenaline, is located in the storage vesicles of the sympatht-tic nerves and the chromaffin cells in the adrenal medulla and is released from thtw sites together with noradrenaline (Geffen et al. 1969, de Potter et al. 1969, Vivelti et al. 1969). Since blood serum contains appreciable amounts of DBH activity it 11as been suggested that the enzyme relased from the sympathetic nerves and ilie chromaffin cells reaches the blood circulation (Weinshilboum and Axelrod 1971 a, b). DBH is a large molecule with a molecular weight of about 290,000 (Friedm. ib and Kaufmann 1965) and may therefore only slowly pass from the interstitial fliiid in which it is released directly into the blood circulation. The lymphatic systvm appears to be an alternative route for DBH to the blood. Recently the occurrence of DBH in human lymph was reported (Aberg et al. 1974). This observation does not by itself prove that the DBH in the lymph emanates from the sympathetic: nerves, since plasma proteins are normal constituents of the lymph. In order to examine whether the DBH in lymph is derived from the sympathetic nerves we have now determined the effect of stimulation of the sympathetic nervous system ip anesthetized cats on the DBH activity in lymph and plasma. The ganglionic stimulatory agent dimethylphenylpiperazinium iodide (DMPP) was used for k massive stimulation of the sympathetic nervous system.6 cats weighing 2.54. 0 kg, anesthetized with sodium pentobarbitone were used in tlw experiments. The thoracic duct was cannulated just below the diaphragm. Lymph w.~ collected in ice-chilled tubes for periods of 30 min. The lymph flow was determined 1,; measuring the volume of the lymph. 3 consecutive doses of DMPP, 0.1 mg/kg, were inject (.# into the femoral vein at intervals of 10 min. The first injection was given 1 h after the start of the lymph collection. Blood samples were taken from the femoral vein every 30 min. Tlie blood pressure was measured in the femoral artery. The DBH activity in plasma and lymph was measured according to the method of Molinoff et aJ.(1971) using tyramine as the substrate with the modification that the DBH assay was performed at pH 5.2 (Weinshilbouin et 01. 1973). The plasma and lymph were diluted with 8 volumes of distilled water befoie the assay. The optimal copper sulphate concentration for the DBH assay of both plasma and lymph was 7 x 10-eM. The DBH activity was expressed in normal octopamine formed per nil lymph per 20 min incubation. The amount of the DBH in the lymph collected for periods cjf30 min was also estimated.