Park Hyung Seo, Kim Se Hoon, Kim Dong Kwan, Kim Kab Sung, Park Hyoung Jin
Department of Physiology, College of Medicine, Konyang University, Daejeon, South Korea.
Pancreas. 2007 Apr;34(3):373-7. doi: 10.1097/MPA.0b013e3180327c2b.
Because functional changes of the pancreas during the ovarian cycle are not fully understood, effects of gonadal steroid hormones on pancreatic amylase content and secretion were investigated.
The estrus cycle of female rats was confirmed by vaginal smear. To mimic the estrus or the diestrus, estradiol 17beta (25 microg/kg) or progesterone (50 mg/kg) was subcutaneously injected to ovariectomized rats once daily for 2 days. Amylase secretion of pancreatic lobules (approximately 6 mg wet weight) was induced by acetylcholine (10-8 approximately 10-4 M).
In normal rats, pancreatic amylase content was not altered during the estrus cycle, whereas spontaneous amylase secretion of pancreatic lobules at the diestrus was significantly higher than that at the estrus. In ovariectomized rat, pancreatic amylase content was markedly reduced, which was restored by either estradiol 17beta or progesterone. Pancreatic lobules of ovariectomized rats spontaneously secreted amylase at the level identical to that at the estrus, which was elevated to the level at the diestrus by progesterone, but not affected by estradiol 17beta. In normal rats, acetylcholine induced amylase secretion much higher at the diestrus than at the estrus. In ovariectomized rats, the acetylcholine-induced amylase secretion was similar to that at the estrus, which was elevated by progesterone, but not affected by estradiol 17beta.
We conclude from the above results that both estradiol 17beta and progesterone are necessary to maintain amylase content in the rat pancreas, but only progesterone exerts a stimulatory effect on spontaneous and stimulated amylase secretion in pancreatic lobules of rats.
由于卵巢周期中胰腺的功能变化尚未完全明了，因此研究了性腺甾体激素对胰腺淀粉酶含量及分泌的影响。
通过阴道涂片确认雌性大鼠的发情周期。为模拟发情期或动情间期，对去卵巢大鼠每日皮下注射17β-雌二醇（25微克/千克）或孕酮（50毫克/千克），持续2天。用乙酰胆碱（10^-8至10^-4摩尔/升）诱导胰腺小叶（约6毫克湿重）分泌淀粉酶。
在正常大鼠中，发情周期中胰腺淀粉酶含量未发生改变，而动情间期胰腺小叶的自发淀粉酶分泌显著高于发情期。在去卵巢大鼠中，胰腺淀粉酶含量明显降低，17β-雌二醇或孕酮均可使其恢复。去卵巢大鼠的胰腺小叶自发分泌淀粉酶的水平与发情期相同，孕酮可将其升高至动情间期水平，但17β-雌二醇对此无影响。在正常大鼠中，乙酰胆碱诱导的淀粉酶分泌在动情间期比发情期高得多。在去卵巢大鼠中，乙酰胆碱诱导的淀粉酶分泌与发情期相似，孕酮可使其升高，但17β-雌二醇对此无影响。
从上述结果我们得出结论，17β-雌二醇和孕酮对维持大鼠胰腺中的淀粉酶含量均是必需的，但只有孕酮对大鼠胰腺小叶中自发和刺激的淀粉酶分泌具有刺激作用。
