NITRIC-OXIDE MEDIATES THE INHIBITORY EFFECTS OF SDPNFLRFAMIDE, A NEMATODE FMRFAMIDE-RELATED NEUROPEPTIDE, IN ASCARIS-SUUM
NITRIC-OXIDE MEDIATES THE INHIBITORY EFFECTS OF SDPNFLRFAMIDE, A NEMATODE FMRFAMIDE-RELATED NEUROPEPTIDE, IN ASCARIS-SUUM
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DOI：
10.1152/jn.1995.74.5.1880
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发表时间：
1995-11-01
影响因子：
2.5
通讯作者：
GEARY, TG
中科院分区：
文献类型：
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作者：
BOWMAN, JW;WINTERROWD, CA;GEARY, TG
1.以猪蛔虫（Ascaris suum）神经肌肉为材料，研究了从自由生活的线虫Panagrellus redivus中分离的两种与Phe-Met-Arg-Phe-NH 2（FMRFamide）相关的神经肽SDPNFLRFamide（PF 1）和SADPNFLRFamide（PF 2）的生理效应. PF 1和PF 2在神经支配和去神经支配的骨骼肌中均使肌膜超极化，并诱导持续性弛缓性麻痹，而不依赖于外部Cl-. PF 1逆转由拟胆碱左旋咪唑、升高的K+或兴奋性线虫FMRFamide相关神经肽KNEFIRFamide或KHEYLRFamide诱导的痉挛性收缩。通过用干扰一氧化氮（NO）合成的试剂（例如，N-硝基-L-精氨酸），而在溶液中释放NO的硝普钠模拟PF 1和PF2.5。通过[H-3]精氨酸转化为[H-3]瓜氨酸来监测NO合酶活性，A.猪皮下组织在肌肉中，但不存在于生殖组织。在这些组织中的NO合酶活性的相对丰度与观察到的[H-3]PF1.6的特异性结合相似。这些结果表明，PF 1和PF 2对线虫体肌的抑制作用是由NO介导的，并且下皮可能在这个过程中起类似于脊椎动物血管内皮的作用。
1. The physiological effects of two Phe-Met-Arg-Phe-NH2 (FMRFamide)-related neuropeptides isolated from the free-living nematode Panagrellus redivivus, SDPNFLRFamide (PF1) and SADPNFLRFamide (PF2), were examined using neuromuscular preparations from the parasitic nematode Ascaris suum.2. PF1 and PF2 hyperpolarized muscle membrane and induced sustained flaccid paralysis, independent of external Cl-, in both innervated and denervated preparations.3. PF1 reversed spastic contractions induced by the cholinomimetic levamisole, elevated K+, or the excitatory nematode FMRFamide-related neuropeptides KNEFIRFamide or KHEYLRFamide.4. PF1 reversal of levamisole contraction was blocked by pre treatment with agents that interfere with nitric oxide (NO) synthesis (e.g., N-nitro-L-arginine), whereas sodium nitroprusside, which releases NO in solution, mimicked PF1 and PF2.5. NO synthase activity, monitored by the conversion of [H-3]arginine to [H-3]citrulline, was twice as abundant in A. suum hypodermis as in muscle, but was not present in reproductive tissue. The relative abundance of NO synthase activity in these tissues was similar to the observed specific binding of [H-3]PF1.6. These results suggest that the inhibitory effects of PF1 and PF2 on nematode somatic muscle are mediated by NO, and that the hypodermis may serve a role in this process analogous to that of the endothelium in vertebrate vasculature.