Energy supply for secretion of protein and fluid in exocrine glands

以大鼠唾液腺的氧耗量来测量分泌液体和蛋白质所需的能量。麻醉下手术分离雄性Wistar大鼠腮腺和颌下腺，动脉、静脉和分泌管插管，用蠕动泵恒速灌流。用卡巴胆碱(CCH)和/或异丙肾上腺素(ISOP)刺激，测定唾液分泌量、唾液淀粉酶(腮腺)、唾液粘蛋白(如颌下腺中的N-乙酰半乳糖胺)和耗氧量。芦荟不能诱导副甲状腺分泌液体，分泌的淀粉酶也不能被检测到。CCH单独引起BOTL腺体液体分泌迅速增加，并允许测量淀粉酶和粘蛋白。CCH单独作用1min后，淀粉酶和粘蛋白的分泌出现一过性增加，随后下降至一个较低的平台水平。在CCH刺激开始后5min，在灌流中加入Isop。颌下腺的液体分泌和耗氧量不受影响，腮腺的分泌量和耗氧量随着耗氧量的增加略有增加。本研究表明，对分泌物刺激增加的能量供应可以满足主要用于电解质和水运输的能量需求。另一方面，分泌刺激对蛋白质分泌的需要可能相对较小，或者在下颌腺的测量范围内。颌下腺和腮腺的粘蛋白和淀粉酶分泌对钙动员剂(CCH)和/或cAMP动员剂(ISOP)的反应相似，提示粘蛋白和淀粉酶的分泌是共同的胞吐机制。

Energy supply for secretion of fluid and protein was measured as oxygen consumption in the isolated perfuse salivary glands from rats. The parotid glands and submandibular glands from male Wistar strain rats were surgically isolated under anesthesia The artery, vein and secretary duct were canulated and arterially perfused: constant perfusion rate using peristaltic pump. The fluid secretion and amylase (parotid gland), mucin (as N-acetylgalactosamine in submandibular gland) in saliva and oxygen consumption were measured during stimulation with carbachol (CCh) and/or isoproterenol (Isop). Isop alnoe did not induce fluid secretion in paroti gland and the secreted amylase was not measured. CCh alone induced a rapid increase of fluid secretion in botl glands and allowed to measure amylase and mucin. CCh alone induce a initial transient increase of amylase and mucin secretion at 1 min with following decline to a low plateau level. At 5 min from start of CCh stimulation, Isop was added to the perfusion. Fluid secretion and oxygen consumption were not influenced in the submandibular glands, but that of parotid gland was a little increased with additional increment of oxygen consumption. The present study indicates that the increased energy supply in response to secretary stimulation could satisfy the energy requirement mainly for transport of electrolytes and water. On the other hand, the ener requirement for protein secretion in response to secretary stimulation could be relatively small, or under the lim of measurement in the mandibular gland. Responses of mucin and amylase secretion to Ca-mobilizing agent (CCh) and/or cAMP-mobilizing agaent (Isop) were similar in the submandibular and parotid glands, suggesting common machinery of exocytosis for mucin and amylase secretion.