166
D. Maymff*, w
J.A. Liebeman, B. Schneider,C.Z. Lexus
of -try,
HillsideHospital,Glen Oaks, New York 11004
Theneuroerrdocrine strategyhasbeenus&extensively inpsycbiatric reseaK&togainmne~ofcentralneIvals system(T) neumchemicalftmctioni.ng. Gmwthhomone(GH)isofparticularmtemst inschizophrmiabecauseoftheinportantmleofdopamine (DA)inthe rqulation of its secretion.Apathologicalinvolvementofthe hypot&lanus in schizophreniamaybe reflectedinvariousnsumbiological fimIingsincludingabnoxmllsecretorypatternsofGH,IxandFsH. mr studyisdesignedtoexamine GHinpatientswiths&iz~thrcrugh the infusionof GHRF, a 40-aminoacid peptideidentifiedin 1982,ard attenpttolocalizethelevel of dysfunction i.ntheCNS-hypothalamic pituitaryaxis. Tenpatientsand fivenormalcontmlsubjectsentered our pilot study,includingthree "firstepisodeV' patientsand seven chmnicschizqhrenics. Cmpariqpatientstocontmlsaswellasfirst episodepatierrtstocontrolsdidnotd~~~arrystatisticdlly significant differencesin GH ?FqmlsetoGHRFasreflectedbythearea However,3-way uMe.rthecurve(AUC),orpercentmeanincrmseofGH. ANOVAccmparingtimetopeakdemonstratedatrend (p= .108)towardsa delayinthefirstepisodegmupcmparedtothetwoothexgrmps.These resultsare at leastpartlyconsistentwith (xv apriorihypothesisthat themwmldbenodifferencesbetween schizcphrenicsandcontrolsubj~ GHmspmsestoW. Tbisisbasedonourassumptionthatdisturbanaes in~secretOrypatternspreviauslydescribedinschiz~a~ mediatedbypathologyatthelevelofthehypothalams or above. Themfore, agoniststimulationofGHreleasethmughhypothalamic medm5smcmlddenmstrate secretoryabnonmlitiesbutnotsowith exogemxls(;RFwhich~dbypassthehypothalarmsanddirectlystinniLate pituitaryscmatotmphs. Thepreliminaryfinding of adelayedreqonse in firstepisodepatientsistenuausgiventhesmdll~ofsubjectsbut merits further investigation,pmposed inalaryerscalestudy. Helping todefinebiologic~~wauldeMbleamoreaccuratedia~isofthe illness,eventuallyleadingto more specificand efficacious trealment. Sincethe secretorypatternsoftheanteriorpituitaryaretosaneexterrt uWerCNS neum&mical activity,pituitaqhonmnes mightbenoninvasivemarkersfor brain function. More specifically, hypothalamic releasingfactorshavebecQneavailablefor clinical use, enablingusti distinguishreducedhypathdLamicst~ationframdiminishedpituitary stow of hormone. This difference is paramomtinlocalizing
[email protected] uponthismumer&minestrategyarealsopropceed,mstnotablyastudy 0fFSHtiLx-I XxponsetoGnRH.