碩士 / 國立彰化師範大學 / 生物學系 / 92 / Abstract
Nitric oxide (NO) is an important intercellular molecule.. NO is produced during the conversion of L-arginine to L-citrulline by nitric oxide synthase (NOS). Many of the physiological effects of NO are mediated by activation of the soluble form of guanylyl cyclase. Previous study has confirmed the existence of NOS in the eyestalk ganglia of the crayfish Procambarus clarkii. The X-organ/sinus gland complex in the eyestalk is a neuroendocrine tissue. Crustacean hyperglycemic hormone (CHH) is released from the X-organ/sinus gland complex and regulates blood glucose levels.The purpose of this study is to investigate the effect of NO on the release of CHH.Results indicate that addition of NO donor (sodium nitroprusside, SNP) or NO precursor (L-arginine) to the incubation medium resulted in decreased CHH release.On the other hand, NO scavenger (Hemoglobin, Hb) and NOS inhibitor (NG-methyl-L-arginine, L-NMMA) enhanced the release of CHH. These results demonstrate that NO inhibits the release of CHH. Previous study indicated that enkephalin has an inhibitory effect on the release of CHH in several crustacean in the present study, this enkephalin-inhibited CHH release was also confirmed in P. clarkii. However, further results showed that SNP-inhibited CHH release was not eliminated by naloxone (opioid receptor antagonist), implying that NO-inhibited CHH release is not due to activation of enkephalinergic pathway. Enkephalin-
inhibited CHH release was not eliminated by L-NMMA indicating that enkephalin-inhibited CHH release is not due to activation of nitregic pathway. Besides, previous study has reported that serotonin enhances the release of CHH. Quantitation of serotonin by high performance liquid chromatography-
electrochemical detection (HPLC-ECD) revealed that SNP and L-arginine decrease the levels of serotonin released from eyestalk ganglia, and L-NMMA increases the level of serotonin from eyestalk ganglia. The combined results suggest that NO negatively regulates CHH release at least, partly by inhibiting serotonergic activity, but the inhibitory effects of NO on CHH release is independent of enkephalinergic pathway.
| Identifer | oai:union.ndltd.org:TW/092NCUE5112032 |
| Creators | 吳佳倫 |
| Contributors | 李英奇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
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