Kong L Y, Maderdrut J L, Jeohn G H, Hong J S
Neuropharmacology Section, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
Neuroscience. 1999;91(2):493-500. doi: 10.1016/s0306-4522(98)00606-x.
Stimulation of murine primary mixed cortical neuron/glia cultures with lipopolysaccharide, an endotoxin, was used as a model for inflammatory disorders of the central nervous system. Lipopolysaccharide (20 microg/ml) increased the secretion of lactate dehydrogenase, a marker for cell injury, and nitric oxide into the culture medium. The lipopolysaccharide-induced release of lactate dehydrogenase into the culture medium was reduced by pituitary adenylate cyclase-activating polypeptide (PACAP) at 10(-14)-10(-12) M. The 27- and 38-amino-acid forms of PACAP were equipotent and their dose-response curves were U-shaped. PACAP6-38, a specific type I PACAP receptor antagonist, blocked the reduction by PACAP38 of the lipopolysaccharide-induced release of lactate dehydrogenase. The lipopolysaccharide-induced secretion of nitric oxide into the culture medium was reduced by PACAP at 10(-14)-10(-12) M and 10(-8)-10(-6) M. The 27- and 38-amino-acid forms of PACAP were equipotent. PACAP6-38 blocked the reduction of the lipopolysaccharide-induced secretion of nitric oxide by PACAP38 at 10(-12) M, but not at 10(-8) M. Vasoactive intestinal polypeptide reduced the lipopolysaccharide-induced release of lactate dehydrogenase into the culture medium at 10(-14)-10(-12) M, but these concentrations of vasoactive intestinal polypeptide had no effect on the lipopolysaccharide-induced secretion of nitric oxide. PACAP6-38 did not effect the reduction of the lipopolysaccharide-induced release of lactate dehydrogenase into the culture medium by 10(-12) M vasoactive intestinal polypeptide. These results indicate that stimulation of type I PACAP receptors by femtomolar concentrations of PACAP can prevent neuron death in a model for inflammatory disorders of the CNS. These results suggest that PACAP is also an extraordinarily potent inhibitor of some microglial functions.
用脂多糖（一种内毒素）刺激小鼠原代混合皮质神经元/神经胶质细胞培养物，以此作为中枢神经系统炎症性疾病的模型。脂多糖（20微克/毫升）会增加细胞损伤标志物乳酸脱氢酶以及一氧化氮向培养基中的分泌。垂体腺苷酸环化酶激活多肽（PACAP）在10⁻¹⁴至10⁻¹²摩尔浓度时，可减少脂多糖诱导的乳酸脱氢酶释放到培养基中。27个氨基酸和38个氨基酸形式的PACAP具有同等效力，其剂量反应曲线呈U形。PACAP6 - 38（一种特异性I型PACAP受体拮抗剂）可阻断PACAP38对脂多糖诱导的乳酸脱氢酶释放的减少作用。脂多糖诱导的一氧化氮向培养基中的分泌在10⁻¹⁴至10⁻¹²摩尔浓度以及10⁻⁸至10⁻⁶摩尔浓度的PACAP作用下会减少。27个氨基酸和38个氨基酸形式的PACAP具有同等效力。PACAP6 - 38可阻断10⁻¹²摩尔浓度的PACAP38对脂多糖诱导的一氧化氮分泌的减少作用，但不能阻断10⁻⁸摩尔浓度时的作用。血管活性肠肽在10⁻¹⁴至10⁻¹²摩尔浓度时可减少脂多糖诱导的乳酸脱氢酶释放到培养基中，但这些浓度的血管活性肠肽对脂多糖诱导的一氧化氮分泌没有影响。PACAP6 - 38不会影响10⁻¹²摩尔浓度的血管活性肠肽对脂多糖诱导的乳酸脱氢酶释放到培养基中的减少作用。这些结果表明，飞摩尔浓度的PACAP对I型PACAP受体的刺激可在中枢神经系统炎症性疾病模型中预防神经元死亡。这些结果表明，PACAP也是某些小胶质细胞功能的一种极其有效的抑制剂。
