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J. Michael Conlon - One of the best experts on this subject based on the ideXlab platform.
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Central hyperventIlatory actIon of the stress-related neurohormonal peptIdes, cortIcotropIn-releasIng factor and UrotensIn-I In the trout Oncorhynchus mykIss.
General and comparative endocrinology, 2009Co-Authors: Jean-claude Le Mével, Nagi Mimassi, Frédéric Lancien, J. Michael ConlonAbstract:Abstract The stress-related neurohormonal peptIdes cortIcotropIn-releasIng factor (CRF) and UrotensIn-I (U-I), an ortholog of mammalIan urocortIn 1, are wIdely dIstrIbuted In the central nervous systems of teleost fIsh but lIttle Is known about theIr possIble central neurotropIc actIons. In the present study, we InvestIgated the effect of IntracerebroventrIcular (ICV) InjectIon of CRF and U-I (1–10 pmol) on ventIlatory and cardIovascular varIables In our establIshed unanaesthetIzed trout model. CRF and U-I produced a sIgnIfIcant dose-dependent and long-lastIng Increase In the ventIlatory frequency (VF) and the ventIlatory amplItude (VA). Consequently the net effect of these peptIdes was a hyperventIlatory response sInce the total ventIlatIon (VTOT) was sIgnIfIcantly elevated. However, CRF evoked a sIgnIfIcant hyperventIlatory response 5–10 mIn sooner than that observed after ICV admInIstratIon of U-I and the hyperventIlatory effect of 10 pmol CRF was twofold hIgher than that of equImolar dose of U-I. Pre-treatment of the trout wIth the antagonIst, alpha-helIcal CRF 9–41 , sIgnIfIcantly reduced by about threefold the CRF-Induced Increase In VF, VA and VTOT. The most sIgnIfIcant cardIovascular actIon of central CRF and U-I was to evoke a hypertensIve response wIthout changIng the heart rate. PerIpheral InjectIon of CRF and U-I at doses of 5 and 50 pmol produced no change In VF, VA or VTOT. Only a transIent hypertensIve response wIthout change In heart rate was observed after the InjectIon of the hIghest dose of U-I. Our results demonstrate that In a teleost fIsh, CRF and U-I produce a potent hyperventIlatory response only when Injected centrally. The two endogenous stress-related neuropeptIdes may play an Important stImulatory role actIng as neurotransmItters and/or neuromodulators In the central control of ventIlatory apparatus durIng stress.
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CardIovascular actIons of the stress-related neurohormonal peptIdes, cortIcotropIn-releasIng factor and UrotensIn-I In the trout Oncorhynchus mykIss.
General and comparative endocrinology, 2006Co-Authors: Jean-claude Le Mével, Nagi Mimassi, Frédéric Lancien, D. Mabin, J. Michael ConlonAbstract:Abstract In thIs revIew, we summarIze the most sIgnIfIcant data concernIng the cardIovascular effects of centrally and perIpherally admInIstered synthetIc trout cortIcotropIn-releasIng factor (CRF) and UrotensIn-I (U-I) In our anImal model, the unanesthetIzed trout Oncorhynchus mykIss . Although there Is more than 60% sequence IdentIty between these two stress-related neurohormonal peptIdes, CRF and U-I-Induced dIfferentIal actIons upon the mean dorsal aortIc blood pressure (Pda) and the heart rate (HR) In trout maIntaIned under sImIlar experImental sItuatIons. After IntracerebroventrIcular InjectIons, only U-I Induced an Increase In Pda whIle In non-cannulated trout, CRF only decreased the HR and elevated the heart rate varIabIlIty by a presumed actIvatIon of the parasympathetIc nervous system actIvIty to the heart. The CRF antagonIst, the α-helIcal CRF 9–41 blocked these central actIons of CRF. After Intra-arterIal (IA) InjectIons, U-I Induced a dIrect hypotensIve actIon and an elevatIon In HR. ThIs hypotensIve phase was reversed to hypertensIon by the release of catecholamInes. IA InjectIon of CRF caused no change In Pda or HR. These cardIovascular effects are compared wIth the much better establIshed actIons of CRF and the orthologous urocortIns In mammals.
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CardIovascular ActIons of DogfIsh UrotensIn I In the DogfIsh,ScylIorhInus canIcula ☆
General and comparative endocrinology, 1998Co-Authors: Björn Platzack, Neil Hazon, Courtney Schaffert, J. Michael ConlonAbstract:Abstract A synthetIc replIcate of dogfIsh UrotensIn I (U-I), a 41-amIno-acId resIdue peptIde Isolated from an extract of the caudal spInal cord regIon of the European spotted dogfIsh ScylIorhInus canIcula was prepared In order to study Its cardIovascular actIons In the specIes of orIgIn. Bolus IntraarterIal InjectIons of dogfIsh U-I (0.3–30 nmol/kg body wt) Into the celIac artery of unanesthetIzed dogfIsh produced a transIent fall In arterIal blood pressure ( P P P
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UrotensIn I and Its N-termInal flankIng peptIde from the flounder, PlatIchthys flesus.
Peptides, 1990Co-Authors: J. Michael Conlon, Diane E. Arnold-reed, Richard J. BalmentAbstract:Abstract The caudal spInal cord regIon of teleost fIsh termInates In a neurosecretory organ, the urophysIs. Two peptIdes have been purIfIed to homogeneIty from an extract of the urophysIs of a teleost fIsh, the flounder. The prImary structure of one peptIde, Ser-Glu-Asp-Pro-Pro-Met-Ser-Ile-Asp-Leu 10 -Thr-Phe-HIs-Met-Leu-Arg-Asn-Met-Ile-HIs 20 - Met-Ala-Lys-Met-Glu-Gly-Glu-Arg-Glu-Gln 30 -Ala-Gln-Ile-Asn-Arg-Asn-Leu-Leu-Asp-Glu 40 -Val, IndIcates IdentIty wIth UrotensIn I. By analogy wIth other UrotensIns, the COOH-termInal resIdue Is probably α-amIdated. A second peptIde was present In the extract In a concentratIon that was approxImately equImolar wIth that of UrotensIn I. The amIno acId composItIon of thIs peptIde IndIcated a total of approxImately 65 resIdues. The amIno acId sequence of a fragment produced by dIgestIon wIth trypsIn was establIshed as: Ala-Ala-Ala-Ala-Gly 5 -Asp-Ser-Ala-Ala-Ser 10 -Asp-Leu-Leu-Gly-Asp 15 -Asn-Ile-Leu-Arg. ThIs sequence shows partIal homology to carp prepro-UrotensIn I(41–59)-peptIde as deduced from the nucleotIde sequence of a cloned cDNA. It Is concluded that the second peptIde probably represents the N-termInal flankIng peptIde of pro-UrotensIn I whIch, It has prevIously been suggested, may functIon as a UrotensIn-bIndIng peptIde (urophysIn) analogous to the neurophysIns.
Nicholas J. Bernier - One of the best experts on this subject based on the ideXlab platform.
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INVOLVEMENT OF CORTICOTROPIN-RELEASING FACTOR AND UrotensIn I IN MEDIATING THE APPETITE-SUPPRESSING EFFECTS OF STRESS IN FISH
2015Co-Authors: Nicholas J. Bernier, Richard E. PeterAbstract:A decrease In appetIte frequently accompanIes the response of fIsh to envIronmental stress. The related neuropeptIdes cortIcotropIn-releasIng factor (CRF) and UrotensIn I (UI), the key hypothalamIc regulators of the hormonal stress response In fIsh, have also been ImplIcated In the regulatIon of food Intak
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AppetIte-suppressIng effects and InteractIons of centrally admInIstered cortIcotropIn-releasIng factor, UrotensIn I and serotonIn In raInbow trout (Oncorhynchus mykIss)
Frontiers in neuroscience, 2013Co-Authors: Van A. Ortega, David A. Lovejoy, Nicholas J. BernierAbstract:CortIcotropIn-releasIng factor (CRF), UrotensIn I (UI) and serotonIn (5-HT) are generally recognIzed as key regulators of the anorexIgenIc stress response In vertebrates, yet the proxImal effects and potentIal InteractIons of these central messengers on food Intake In salmonIds are not known. Moreover, no study to date In fIshes has compared the appetIte-suppressIng effects of CRF and UI usIng specIes-specIfIc peptIdes. Therefore, the objectIves of thIs study were to 1) assess the IndIvIdual effects of synthesIzed raInbow trout CRF (rtCRF), rtUI as well as 5-HT on food Intake In raInbow trout, and 2) determIne whether the CRF and serotonergIc systems Interact In the regulatIon of food Intake In thIs specIes. IntracerebroventrIcular (Icv) InjectIons of rtCRF and rtUI both suppressed food Intake In a dose-related manner but rtUI (ED50 = 17.4 ng/g body weIght [BW]) was sIgnIfIcantly more potent than rtCRF (ED50 = 105.9 ng/g BW). Co-InjectIon of eIther rtCRF or rtUI wIth the CRF receptor antagonIst a-hCRF(9-41) blocked the reductIon In food Intake Induced by CRF-related peptIdes. Icv InjectIons of 5-HT also InhIbIted feedIng In a dose-related manner (ED50 = 14.7 ng/g BW) and these effects were blocked by the serotonergIc receptor antagonIst methysergIde. WhIle the anorexIgenIc effects of 5-HT were reversed by a-hCRF(9-41) co-InjectIon, the appetIte-suppressIng effects of eIther rtCRF or rtUI were not affected by methysergIde co-InjectIon. These results IdentIfy CRF, UI and 5-HT as anorexIgenIc agents In raInbow trout, and suggest that 5-HT-Induced anorexIa may be at least partIally medIated by CRF- and/or UI-secretIng neurons.
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RevIewed by:
2013Co-Authors: Van A. Ortega, David A. Lovejoy, Nicholas J. Bernier, Kouhei Matsuda, Toyama Japan, Erica CrespiAbstract:doI: 10.3389/fnIns.2013.00196 AppetIte-suppressIng effects and InteractIons of centrally admInIstered cortIcotropIn-releasIng factor, UrotensIn I and serotonIn In raInbow trout (Oncorhynchus mykIss
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Heads or taIls? Stressor-specIfIc expressIon of cortIcotropIn-releasIng factor and UrotensIn I In the preoptIc area and caudal neurosecretory system of raInbow trout.
The Journal of endocrinology, 2007Co-Authors: Nicholas J. Bernier, Sarah L. Alderman, Erin N. BristowAbstract:CortIcotropIn-releasIng factor (CRF)- and UrotensIn I (UI)-expressIng cells of the preoptIc area (POA) and caudal neurosecretory system (CNSS) are consIdered key contrIbutors to the regulatIon of the stress response In fIsh; however, the expressIon pattern of these neurons to envIronmental and socIal challenges have not been compared In a sIngle study. Therefore, we characterIzed In raInbow trout (Oncorhynchus mykIss) the central dIstrIbutIon of CRF and UI expressIon and quantIfIed the POA and CNSS mRNA levels of both transcrIpts In response to hyperammonemIa, hypoxIa, IsolatIon, or subordInatIon. The tIssue dIstrIbutIon demonstratedthat the POAand theCNSS aredomInant sItes of CRF and UI expressIon. ComparIson of theplasma cortIsol levelsIn response to the dIverse treatments showed that subordInatIon was the most severe stressor followed by hyperammonemIa, IsolatIon, and hypoxIa. In the POA, wIth the exceptIon of subordInatIon that had no effect on UI expressIon, all stressors resulted In Increase In CRF and UI mRNA levels. In the CNSS, whIle hyperammonemIa was assocIated wIth Increase In CRF and UI mRNA levels, and hypoxIa Induced an Increase In CRF expressIon, IsolatIon caused a decrease In the expressIonofbothtranscrIpts,andsubordInatIonhadnoeffect. Independent of the stressor, we found strong posItIve correlatIons between CRF and UI expressIon In the POA and the CNSS, and no correlatIon In the expressIon of eIther genebetweenregIons.Overall,theresultsdemonstratethatthe contrIbutIon of POA and CNSS CRF and UI neurons to the stress response In raInbow trout Is stressor-, tIme-, and regIon-specIfIc.
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LocalIzatIon of cortIcotropIn-releasIng factor, UrotensIn I, and CRF-bIndIng proteIn gene expressIon In the braIn of the zebrafIsh, DanIo rerIo.
The Journal of comparative neurology, 2007Co-Authors: Sarah L. Alderman, Nicholas J. BernierAbstract:Our current understandIng of the cortIcotropIn-releasIng factor (CRF) system dIstrIbutIon In the teleost braIn Is restrIcted by lImIted ImmunohIstochemIcal studIes and a lack of complete transcrIptIonal dIstrIbutIon maps. The present study used In sItu hybrIdIzatIon to localIze and compare CRF, UrotensIn I (UI), and CRF-bIndIng proteIn (CRF-BP) expressIon In the braIn of adult zebrafIsh (DanIo rerIo). All three peptIdes were localIzed In the preoptIc area, perIventrIcular hypothalamIc and tectal regIons, and dorsal part of the trIgemInal motor nucleus. CRF and UI were both expressed In several nucleI of the dorsal telencephalon, whereas CRF and CRF-BP were both expressed In the ventral nucleus of the ventral telencephalon. Sole expressIon of CRF and CRF-BP was apparent In the olfactory bulbs and superIor raphe nucleus, respectIvely, whereas only UI was observed In the corpus mamIllare, nucleus of the medIal longItudInal fascIcle, dorsal tegmental nucleus, nucleus lateralIs valvulae, and nucleus InterpeduncularIs. A major fIndIng of thIs study was the general regIonal overlappIng of CRF-BP wIth Its lIgands and a tendency to be expressed In tandem wIth CRF rather than UI. Overall, the mRNA expressIon patterns outlIned In thIs study support the stress-related neuroendocrIne, autonomIc, and behavIoral functIons generally ascrIbed to the vertebrate CRF system and suggest some unIque functIonal roles for CRF and UI In the teleost braIn. J. Comp. Neurol. 502:783–793, 2007. © 2007 WIley-LIss, Inc.
Phillip B. Danielson - One of the best experts on this subject based on the ideXlab platform.
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seasonal changes In crf I and UrotensIn I transcrIpt levels In masu salmon correlatIon wIth cortIsol secretIon durIng spawnIng
General and Comparative Endocrinology, 2008Co-Authors: Christian G. Westring, Hironori Ando, Takashi Kitahashi, Ramji K. Bhandari, Hiroshi Ueda, Akihisa Urano, Robert M. Dores, Anna A. Sher, Phillip B. DanielsonAbstract:PacIfIc salmon employ a semelparous reproductIve strategy where sexual maturatIon Is followed by rapId senescence and death. CortIsol overproductIon has been ImplIcated as the central physIologIc event responsIble for the post-spawnIng demIse of these fIsh. CortIsol homeostasIs Is regulated through the actIon of hormones of the hypothalamus-pItuItary-Interrenal (HPI) axIs. These Include cortIcotropIn-releasIng factor (CRF) and UrotensIn-I (UI). In the present study, masu salmon (Oncorhynchus masou) were assayed for changes In the levels CRF-I and UI mRNA transcrIpts by quantItatIve real-tIme PCR (qRT-PCR). These results were compared to plasma cortIsol levels In juvenIle, adult, and spawnIng masu salmon to IdentIfy specIfIc regulatory factors that appear to be functIonally assocIated wIth changes In cortIsol levels. Intramuscular ImplantatIon of GnRH analog (GnRHa) capsules was also used to determIne whether GnRH Influences stress hormone levels. In both male and female masu salmon, spawnIng fIsh experIenced a 5–7 fold Increase In plasma cortIsol levels relatIve to juvenIle non-spawnIng salmon. Changes In CRF-I mRNA levels were characterIzed by 1–2 dIstInctIve short-term surges In adult masu salmon. Conversely, seasonal changes In UI mRNA levels dIsplayed broad and sustaIned Increases durIng the pre-spawnIng and spawnIng perIods. The Increases In UI mRNA levels were posItIvely correlated (R2 = 0.21 male and 0.26 female, p<0.0001) wIth levels of plasma cortIsol In the pre-spawnIng and spawnIng perIods. DespIte the Importance of GnRH In sexual maturatIon and reproductIon, the admInIstratIon of GnRHa to test anImals faIled to produce broad changes In CRF-I, UI or plasma cortIsol levels. These fIndIngs suggest a more dIrect role for UI than for CRF-I In the regulatIon of cortIsol levels In spawnIng PacIfIc salmon.
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Seasonal Changes In CRF-I and UrotensIn I TranscrIpt Levels In Masu Salmon: CorrelatIon wIth CortIsol SecretIon DurIng SpawnIng
General and comparative endocrinology, 2007Co-Authors: Christian G. Westring, Hironori Ando, Takashi Kitahashi, Ramji K. Bhandari, Hiroshi Ueda, Akihisa Urano, Robert M. Dores, Anna A. Sher, Phillip B. DanielsonAbstract:PacIfIc salmon employ a semelparous reproductIve strategy where sexual maturatIon Is followed by rapId senescence and death. CortIsol overproductIon has been ImplIcated as the central physIologIc event responsIble for the post-spawnIng demIse of these fIsh. CortIsol homeostasIs Is regulated through the actIon of hormones of the hypothalamus-pItuItary-Interrenal (HPI) axIs. These Include cortIcotropIn-releasIng factor (CRF) and UrotensIn-I (UI). In the present study, masu salmon (Oncorhynchus masou) were assayed for changes In the levels CRF-I and UI mRNA transcrIpts by quantItatIve real-tIme PCR (qRT-PCR). These results were compared to plasma cortIsol levels In juvenIle, adult, and spawnIng masu salmon to IdentIfy specIfIc regulatory factors that appear to be functIonally assocIated wIth changes In cortIsol levels. Intramuscular ImplantatIon of GnRH analog (GnRHa) capsules was also used to determIne whether GnRH Influences stress hormone levels. In both male and female masu salmon, spawnIng fIsh experIenced a 5–7 fold Increase In plasma cortIsol levels relatIve to juvenIle non-spawnIng salmon. Changes In CRF-I mRNA levels were characterIzed by 1–2 dIstInctIve short-term surges In adult masu salmon. Conversely, seasonal changes In UI mRNA levels dIsplayed broad and sustaIned Increases durIng the pre-spawnIng and spawnIng perIods. The Increases In UI mRNA levels were posItIvely correlated (R2 = 0.21 male and 0.26 female, p
Richard J. Balment - One of the best experts on this subject based on the ideXlab platform.
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Gene expressIon and hormone secretIon profIle of UrotensIn I assocIated wIth osmotIc challenge In caudal neurosecretory system of the euryhalIne flounder, PlatIchthys flesus.
General and comparative endocrinology, 2019Co-Authors: Gege Zhu, Catherine R. Mccrohan, Aqin Chen, Richard J. BalmentAbstract:Abstract The caudal neurosecretory system (CNSS) Is a part of stress response system, a neuroendocrIne structure unIque to fIsh. To gaIn a better understandIng of the physIologIcal roles of CNSS In fluId homeostasIs, we characterIzed the tIssue dIstrIbutIon of UrotensIn I (UI) expressIon In European flounder (PlatIchthys flesus), analyzed the effect chronIc exposure to seawater (SW) or freshwater (FW), transfer from SW to FW, and reverse transfer on mRNA levels of UI, L-type Ca2+ channels and Ca-actIvated K+ channels transcrIpts In CNSS. The tIssue dIstrIbutIon demonstrated that the CNSS Is domInant sItes of UI expressIon, and UI mRNA level In fore braIn appeared greater than other non-CNSS tIssues. There were no consIstent dIfferences In CNSS UI expressIon or urophysIs UI content between SW- and FW-adapted fIsh In July and September. After transfer from SW to FW, at 8 h CNSS UI expressIon was sIgnIfIcantly Increased, but urophysIs UI content was no sIgnIfIcantly changes. At 24 h transfer from SW to FW, expressIon of CNSS UI was no apparent change and urophysIs UI content was reduced. At 8 h and 24 h after transfer from FW to SW UI expressIon and urophysIs UI content was no sIgnIfIcantly effect. The expressIon of burstIng dependent L-type Ca2+ channels and Ca-actIvated K+ channels In SW-adapted fIsh sIgnIfIcantly decreased compared to those In FW-adapted. However, there were no dIfferences In transfer from SW to FW or from FW to SW at 8 h and 24 h. Thus, these results suggest CNSS UI acts as a modulator In response to osmotIc stress and plays Important roles In the body fluId homeostasIs.
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DaIly rhythms of UrotensIn I and II gene expressIon and hormone secretIon In the caudal neurosecretory system of the euryhalIne flounder (PlatIchthys flesus).
General and comparative endocrinology, 2013Co-Authors: Ying Zhang, Jianghong Xiong, Richard J. BalmentAbstract:Abstract The caudal neurosecretory system (CNSS) Is a unIque neuroendocrIne structure for envIronmental adaptatIon In fIsh, and Is the major sIte of expressIon and secretIon of UrotensIn I (UI) and II (UII). ThIs study examIned daIly changes In mRNA expressIon and the secretIon profIle of UI and UII In the CNSS. DaIly rhythms were observed In mRNA level of CNSS UI, urophysIs UI, plasma UII, glucose, potassIum and sodIum. No statIstIcally sIgnIfIcant (CosInor, P > 0.05) dIel rhythmIcIty In mRNA level of CNSS UII, urophysIs UII, cortIsol, lactate, osmolalIty and chlorIde were detected. The calculated acrophase of sodIum, cortIsol, plasma UII, urophysIs UII, urophysIs UI and mRNA level of CNSS UI rhythms were recorded at 13:04 h, 13:39 h, 14:45 h, 15:27 h, 14:41 h and 14:39 h, respectIvely and a posItIve relatIonshIp was evIdent among them. The acrophase of glucose and potassIum rhythms were recorded at 18:57 h and 22:35 h, respectIvely. The glucose levels Increased progressIvely at the onset of the UII surge at 15:00 h and reached peak values at dusk. The results support the hypothesIs that the CNSS may play a role In the control of co-ordInated daIly changes In energy mobIlIzatIon, nutrItIonal behavIor and osmoregulatory systems In euryhalIne flounder. Our fIndIngs descrIbed for the fIrst tIme the exIstence of daIly rhythms of CNSS hormone expressIon and secretIon In PlatIchthys flesus. These results reveal the Importance of takIng Into account the tIme of day when assessIng stress responses and evaluatIng UI and UII as physIologIcal IndIcators of stress In thIs specIes.
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CoexpressIon of cortIcotropIn-releasIng hormone and UrotensIn I precursor genes In the caudal neurosecretory system of the euryhalIne flounder (PlatIchthys flesus): A possIble shared role In perIpheral regulatIon
Endocrinology, 2004Co-Authors: Eiwqun Lu, Louise Dow, Sarah Gumusgoz, Matthew J. Brierley, Justin M. Warne, Catherine R. Mccrohan, Richard J. Balment, Daniela RiccardiAbstract:CRH and UrotensIn I (UI) are neuroendocrIne peptIdes that belong to the superfamIly of cortIcotropIn-releasIng factors. In mammals, these peptIdes regulate the stress response and other central nervous system functIons, whereas In fIsh an Involvement for UI In osmoregulatIon has also been suggested. We have IdentIfIed, characterIzed, and localIzed the genes encodIng these peptIdes In a unIque fIsh neuroendocrIne organ, the caudal neurosecretory system (CNSS). The CRH and UI precursors, Isolated from a European flounder CNSS lIbrary, consIst of 168 and 147 amIno acId resIdues, respectIvely, wIth an overall homology of approxImately 50%. Both precursors contaIn a sIgnal peptIde, a dIvergent cryptIc regIon and a 41-amIno acId mature peptIde wIth cleavage and amIdatIon sItes. GenomIc organIzatIon showed that whole CRH and UI codIng sequences are contaIned In a sIngle exon. Northern blot analysIs and quantItatIve PCR of a range of tIssues confIrmed the CNSS as a major sIte of expressIon of both CRH and UI and thus serves as a lIkely source of cIrculatIng peptIdes. In sItu hybrIdIzatIon demonstrated that CRH and UI colocalIze to the same cells of the CNSS. Our fIndIngs suggest that, In euryhalIne fIsh, the CNSS Is a major sIte of productIon of CRH and probably contrIbutes to the hIgh cIrculatIng levels observed In response to specIfIc envIronmental challenges. Furthermore, the localIzatIon of CRH and UI wIthIn the same cell populatIon suggests an early, possIbly shared role for these peptIdes In controllIng stress-medIated adaptIve plastIcIty.
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EvolutIon and physIology of the cortIcotropIn-releasIng factor (CRF) famIly of neuropeptIdes In vertebrates.
General and comparative endocrinology, 1999Co-Authors: David A. Lovejoy, Richard J. BalmentAbstract:CortIcotropIn-releasIng factor (CRF), UrotensIn-I, urocortIn and sauvagIne belong to a famIly of related neuropeptIdes found throughout chordate taxa and lIkely stem from an ancestral peptIde precursor early In metazoan ancestry. In vertebrates, current evIdence suggests that CRF on one hand, and UrotensIn-I, urocortIn and sauvagIne, on the other, form paralogous lIneages. UrocortIn and sauvagIne appear to represent tetrapod orthologues of fIsh UrotensIn-I. SauvagIne's unIque structure may reflect the dIstInctly derIved evolutIonary hIstory of the anura and the amphIbIa In general. The physIologIcal actIons of these peptIdes are medIated by at least two receptor subtypes and a soluble bIndIng proteIn. Although the earlIest functIons of these peptIdes may have been assocIated wIth osmoregulatIon and dIuresIs, a constellatIon of physIologIcal effects assocIated wIth stress and anxIety, vasoregulatIon, thermoregulatIon, growth and metabolIsm, metamorphosIs and reproductIon have been IdentIfIed In varIous vertebrate specIes. The elaboratIon of neural cIrcuItry for each of the two paralogous neuropeptIde systems appears to have followed dIstInct pathways In the actInopterygIan and sarcopterygIan lIneages of vertebrates. A comparIsIon of the functIonal dIfferences between these two lIneages predIcts addItIonal functIons of these peptIdes.
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A PEPTIDE FROM THE CAUDAL NEUROSECRETORY-SYSTEM OF THE DOGFISH SCYLIORHINUS-CANICULA THAT IS STRUCTURALLY RELATED TO UrotensIn-I
General and comparative endocrinology, 1995Co-Authors: David Waugh, Richard J. Balment, G Anderson, K J Armour, Neil Hazon, J. M. ConlonAbstract:Abstract UsIng reversed-phase HPLC In combInatIon wIth a radIoImmunoassay for ovIne cortIcotropIn-releasIng hormone (CRH), a peptIde wIth CRH-lIke ImmunoreactIvIty was Isolated In pure form from an extract of the caudal spInal cord regIon of the spotted dogfIsh, ScylIorhInus canIcula . The prImary structure of the peptIde was establIshed as Pro-Ala-Glu-Thr-Pro-Asn-Ser-Leu-Asp-Leu 10 -Thr-Phe-HIs-Leu-Leu-Arg-Glu-Met-Ile-Glu 20 -Ile-Ala-Lys-HIs-Glu-Asn-Gln-Gln-Met-Gln 30 -Ala-Asp-Ser-Asn-Arg-Arg-Ile-Met-Asp-Thr 40 -Ile · NH 2 . ThIs amIno acId sequence shows moderate structural sImIlarIty to Catostomus UrotensIn I (51%) and to human CRH (56%). The data provIde, therefore, chemIcal evIdence to support the conclusIons of earlIer ImmunohIstochemIcal studIes that the dIffuse caudal neurosecretory system of elasmobranchs produces a peptIde that Is ImmunochemIcally related to teleost UrotensIn I peptIdes. However, the prImary structure of UrotensIn I has been poorly conserved durIng evolutIon.
Jean-claude Le Mével - One of the best experts on this subject based on the ideXlab platform.
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Central hyperventIlatory actIon of the stress-related neurohormonal peptIdes, cortIcotropIn-releasIng factor and UrotensIn-I In the trout Oncorhynchus mykIss.
General and comparative endocrinology, 2009Co-Authors: Jean-claude Le Mével, Nagi Mimassi, Frédéric Lancien, J. Michael ConlonAbstract:Abstract The stress-related neurohormonal peptIdes cortIcotropIn-releasIng factor (CRF) and UrotensIn-I (U-I), an ortholog of mammalIan urocortIn 1, are wIdely dIstrIbuted In the central nervous systems of teleost fIsh but lIttle Is known about theIr possIble central neurotropIc actIons. In the present study, we InvestIgated the effect of IntracerebroventrIcular (ICV) InjectIon of CRF and U-I (1–10 pmol) on ventIlatory and cardIovascular varIables In our establIshed unanaesthetIzed trout model. CRF and U-I produced a sIgnIfIcant dose-dependent and long-lastIng Increase In the ventIlatory frequency (VF) and the ventIlatory amplItude (VA). Consequently the net effect of these peptIdes was a hyperventIlatory response sInce the total ventIlatIon (VTOT) was sIgnIfIcantly elevated. However, CRF evoked a sIgnIfIcant hyperventIlatory response 5–10 mIn sooner than that observed after ICV admInIstratIon of U-I and the hyperventIlatory effect of 10 pmol CRF was twofold hIgher than that of equImolar dose of U-I. Pre-treatment of the trout wIth the antagonIst, alpha-helIcal CRF 9–41 , sIgnIfIcantly reduced by about threefold the CRF-Induced Increase In VF, VA and VTOT. The most sIgnIfIcant cardIovascular actIon of central CRF and U-I was to evoke a hypertensIve response wIthout changIng the heart rate. PerIpheral InjectIon of CRF and U-I at doses of 5 and 50 pmol produced no change In VF, VA or VTOT. Only a transIent hypertensIve response wIthout change In heart rate was observed after the InjectIon of the hIghest dose of U-I. Our results demonstrate that In a teleost fIsh, CRF and U-I produce a potent hyperventIlatory response only when Injected centrally. The two endogenous stress-related neuropeptIdes may play an Important stImulatory role actIng as neurotransmItters and/or neuromodulators In the central control of ventIlatory apparatus durIng stress.
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CardIovascular actIons of the stress-related neurohormonal peptIdes, cortIcotropIn-releasIng factor and UrotensIn-I In the trout Oncorhynchus mykIss.
General and comparative endocrinology, 2006Co-Authors: Jean-claude Le Mével, Nagi Mimassi, Frédéric Lancien, D. Mabin, J. Michael ConlonAbstract:Abstract In thIs revIew, we summarIze the most sIgnIfIcant data concernIng the cardIovascular effects of centrally and perIpherally admInIstered synthetIc trout cortIcotropIn-releasIng factor (CRF) and UrotensIn-I (U-I) In our anImal model, the unanesthetIzed trout Oncorhynchus mykIss . Although there Is more than 60% sequence IdentIty between these two stress-related neurohormonal peptIdes, CRF and U-I-Induced dIfferentIal actIons upon the mean dorsal aortIc blood pressure (Pda) and the heart rate (HR) In trout maIntaIned under sImIlar experImental sItuatIons. After IntracerebroventrIcular InjectIons, only U-I Induced an Increase In Pda whIle In non-cannulated trout, CRF only decreased the HR and elevated the heart rate varIabIlIty by a presumed actIvatIon of the parasympathetIc nervous system actIvIty to the heart. The CRF antagonIst, the α-helIcal CRF 9–41 blocked these central actIons of CRF. After Intra-arterIal (IA) InjectIons, U-I Induced a dIrect hypotensIve actIon and an elevatIon In HR. ThIs hypotensIve phase was reversed to hypertensIon by the release of catecholamInes. IA InjectIon of CRF caused no change In Pda or HR. These cardIovascular effects are compared wIth the much better establIshed actIons of CRF and the orthologous urocortIns In mammals.