• — TAP CHi NGHI§N CI>U Y HQC
VAI TRO SINH LY CCiA GLUTAMATE d DA DAY
N g u y i n Van Tu'dng L' glutamate la mdt axit amin cd nhiiu chuc ndng khdc nhau trong co thi nhw Id chit trung gian cOa cac qui trinh chuyen hda. chit kich thich ddn tmyin thin kinh nao bd, hay lidn quan din kh^ ndng cdm nhdn v/, K/ia nang t^o vj umami hay vj nggt thjt cCia glutamate dS Idm cho glutamate vd cdc muii cua nd du-<^c su- di^ng r^ng rai trdn thi gidi vdi vai tro Id mdt chit diiu vj thuc phim. Bdn canh dt, nhieu nghien cCeu gin ddy cang da kham pha them vai fro ctJa glutamate ddi vdi qud trinh tidu hda thuc phim t^i d? day Bai tdng quan hay la t$p hop nhOng nghidn cuv vi tdc dung cua glutamate dii vdi qud trinh tidu hda thuc phim d d? day TO khoa: vai tro sinh ly, glutamate, umami
I. Giai THIEU
Cdch dgy han 100 ngm, mflt gigo s u ngudi Nhat Ban tdn Ig Kikunae Ikeda da nhgn t h i y rcing trong thuc p h i m , bfln canh b i n vi c a ban la ngot, chua, mgn, d i n g d u a c cgc nhg khoa hoc thdl bay gid cdng nhgn cdn cfl mflt vi khdc, giup mang lai vj ngon cho thuc p h i m Ndm 1908, giao s u Ikeda da tgch c h i l t thanh cong glutamate t d tao b i l n , nguygn lieu chlnh Se niu mdn nudc dung truyen thong Dashi ciJa ngudi Nhat Ban va nhan t h i y r i n g chinh glutamate da mang lai vi ngon eho mdn nudc diing nay, dng da dgt tgn cho vi eua glutamate la';i umamt, b i t nguon t u t i l n g Nhat ed nghla la Vj ngon Trong t i l n g Vidt, chting ta cd t h i hieu v| umami la vi ngpt thit. S y tranh cSi vi umami ed phai la vj c a ban hay khflng da d i l n ra trong mflt thdi gian dai cho den nam 2000, khi cac nha khoa hpe thupc Bai hoe Miami cua Hoa Ky kham pha ra thy the cua glutamate d tren lu'&i [1], TO dd, vi umami d u g c cflng nhgn fnptcSch rflng rai trong gidi khoa hpc la vj c a ban thi> nam ben cgnh cgc vi ngpt, chua, man va ding.
Vj umami la vj cua glutamate va mflt so nucleotit pho b i l n la inosinate va guanyiate, Trong do, glutamate la e h l t tao vi umami chu y^u, thudng gap n h l t la mufli natri cua nd hay c6n goi ig ml chinh. Hien nay, monosodium TnUfngD^ihocYHaNQi
L.GIutamate (MSG) hay ml chinh dugc s u dyng rflng rai trong che bien thue p h i m hang nggy eOng nhu trong cflng nghg c h l biln thuc pham vdi vai trd la mflt chat dieu v\ Tinh an todn cua mi chinh trong s d dung c h l biln thyc pham da d u a c cac to chuc Y t l va cham sdc sue khoe trdn the gidi cdng nhan nhu Gy ban hdn hap chuygn gia v l phu gia thuc pham eua to ehue Y t l T h i gidi va to chuc Nflng Luang Lien Hiep Quoc (JECFA), Uy ban Khoa hoc ve Thue pham cua Cdng dflng chung chgu Au (EC/ SCF). Cae to chuc nay cung cdng nhgn lieu lugng s u dung hang ngay eua mi chinh lg khdng xgc dmh va khdng ed hgi cho sdc khoe
Ben canh dd, nhung nghien cdu g i n day edn cho t h i y khi glutamate duae bd sung vao thyc pham thi cd kha nang kich thich qua trinh tidu hda thuc p h i m tai da dgy Bai tong quan ngy la tdm luac nhung nghign cdu g i n day v l vai trd smh 1^ cua glutamate d da dgy.
II. CON DU'aNG DAN TRUYDN TIN HIEU COA GLUTAMATE 6" DA DAY
Nam 2000, Niijima vg cflng s u dg tien hanh do dap dng eua dgy than kinh p h i vi dfli vdi glutamate Ong nhgn thay r i n g , dung dich glutamate d khoang mieng vdi nflng do 150mmol/L trong 10 phiit ed t h i kich thieh dap
l i i i
TjBkP CHl NGHIEN CCPU Y HQC ung cua dgy thin kinh ly tam phi vj dg day mdt each rO rang. Tic dfl khu cyc cOa dgy ly tam trudc vg tgi thdi dilm 30, 60, 90 phCit sgu khi glutamate kleh thieh vj gigc d .khoang mi$ng lln lugt la r3,8 ± 3,8; 86,4 ± 3,1'; 100,9
± 2,6* va 142,1 ± 5,2" xung ddng/gigy. Bgn cgnh dd, khi dua glutamgte vao dg day, glutg- mate cd thi kich thich dap ung cCig day thin kmh ly tam phi vj dg day (hlnh 1, dudi trai), tie dfl khu cue cCig dgy thin kinh ly tgm phi vj dg dgy trudc vg tgi thdi dilm 30, 60, 90 phiit sgu khi dua glutamate vgp dg dgy la 60,0 ± 2,6. 63,9 ± 1,3, 72,2 ± 1,8*, 82,8 ± 2,9* xung dflng/5 giay , vg dgy thin kinh hudng tgm phi vi dg day (hlnh 1, phli) vdi tie dd khd eye
trudc va tgi thdi dilm 30, 60, 90 phiit sgu khi dua glutamate vgp dg day lln lugt la 59,2 ± 3,3, 112,2 ± 3,5', 109,3 ± 4,0* and 96,0 ± 4,4' xung dflng /5 gigy. Gia trj cfl * la nhdng gia trj cfl sy gia tang rd rgt khi sp sgnh vdi dgp dng trudc khi cd glutamate, p s 0,05 (ANOVA, Scheffg test) [3],
Bgn cgnh dd, din nam 2006, Uneygma vd cflng sy dg qugn sat sy dgp ung cug day thin kinh hudng tam phi vj dg dgy dli vdi 20 logi axit amin phi biln trong ca thi Trong thi nghigm nay. dung dich cac axit amin vdi ning dO 150 mmol/l dup'c dua vgo da day ehuflt va sy dap dng cua day thin kmh phi vj hudng tam dugc do lign tuc
Kich thieh vj giae
Sy khu cyc
Day thin kmh ly tam phi vi dg day 150mmol/L, 10 mm
Oudng dgc: 100 xung dflng/ giay
Day thin kinh huang tgm (nhgy elm vdi Glutamate cua dg dgy)
MSG 150mmol/L, 3mL. sy khu cyc
Oudng ngang: 30 phdt
Hinh 1. Hinh ben tren: Dgp ii'ng ciJia d l y t h i n kinh ly t i m p h i vj da dgy dfli vdi kich thich cua glutamate d khoang mif ng va da day
Hlnh ban du'di: Dap ivng cua day t h i n kinh hu'dng tgm p h i vj da day dfli vdi gluta- mate dup'c du'a vgo dg dgy
TCNCYH 79 (2) - 2012
• T * P CHi NGHIEN CCfU Y HQC K§t qua nghien ciru cho thay trong 20 I091 10mmol/l. fii^u nSy trSl ngifffc hoSn toan v * i axit amin, day than kmh phe vi hirong tam chi vi#o M m glutamate vSo tmh macti. 0 Ii4u Irong sap irng yoi glutamate [5] 30mg glutamate/kg t h i trpng cjif^c tiSm vSo tTnh Trong thi nghiem nay Uneyama va c j n g mach cua chu«t, cSc nhS khoa hoc v l n khing sir nhan thay su flap ung cua day Ihan kmh quan s4t dugrc su gia t i n g trong t&:do k h * cu'C pile Vl con phu thuoc uao nong do glutamate asng yi. Nhu vSy, su lip irng ciia day than (tilnh 2, phai) va nhan t h i y ngudng ndng dO kinh phe vi da dSy rO rang phg thuOc vio su cd Je da day co the cam nhan duoc la du-d'i mSt cua glutamate * trong da day [5]
I
l.iil
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-• I
Hoat dong cua day than kmh phe vi huo'ng tgm
Hinh 2: Trai: Ddy thdn kmh huang tam phd vi da ddy ddp 0-ng v&i cdc axit amin duuc dwa vdo da day Mdi dung dich axit amin (1 SOmmol 2mi) du-ac dira vao da day cua chudt. Tdc dd khu- circ trung binh tai thoi diSm 20 phut dtfoc the Ivdn trdn bidu dd: mdi cgt vd du-dng ngang thi. hidn gid tn trung bmh ± do lech tieu chuan cd douc h'f 5 con chudt
"P < 0,01 so VOI dung dich mudi (KruskRl-Wallis test).
Phai Su dap u-ng phu thuoc vac nong dd cua glutamate trong hoat d^ng cua ddy thdn kinh l^mng tarn Mdi dung dich glutamate i/o/ nong di? 50, 150. 450 mmol/l, 2ml du-oc du-a vao dg ddy cua chuot va tdc do khu cue trung l)inh tai thdl diSm 20 phQt diK/c thS hi$n tren biiu dd. Mdi cpt va duong aoc the hien gia tn trung binh ± do Ideh tieu chudn
Mot nghien cuu vao nam 2007 cud cac nha khoa hpc dg lgm sang td nguyen nhgn eua k i t qua 'hi nghiem quan sat duae cua Uneyama B l n g phuang phgp m i l n dich huynh quang, cac nha fthoa hoc dd dm ra thu the cua glutamate o trong da dgy cua ehuflt [4].
TAP CHl NGHlfeN CO'U Y HQC •
B6 la mGluRI (metabotropic Glutamate receptor type 1) (hlnh 3).
Nhu vjy, khSng chi cd th4 c i m hh^n du'oc glutannate c6 trong cac loai thu'c phinn chung ta an vao thing qua vi umami Sk da day sin sang ti4p nhan loai thu'C phim dd mi cdn c6 t h i cim nhan ducrc su' c6 mat cua glutamate I) trong 6ng tiSu hda n h * thg th4 cua glutamate * da day thdng qua day thin kinh ph6 vj.
- '^. # * * '
Hlnh 3: Phat hien ra m G l u R I (metabotropic Glutamate receptor type 1} b a i ky tliu$t m i l n djch huynh q u a n i j . (A) Hinh anh cung tieu diem cua m G l u R t (mau dd) t r f l | m j | | hang vj (nun ten m a u ' a n g ) va p e p s i n o g e n C (B) t a i c u n g 1 vi tri. (C) Hinh anh ket hQrp cho thay phan u n g m i e n d i c h c t i o m G l u R I dU'O'C d a n h dau tai be mat cua te b a o chfrth
III. VAI TRO SINH LY CUA GLUTAMATE CT DA DAY
Ngay ti) dau nhung nam 1990. mot nha khoa hoc ngudi Nga da nhan thay rang khi cho Ch6 an thljc pham cd bo sung chat tao vi umami (ket hop giua glutamate va inosinate) cd the lanl gia tang su tiet dich vi (hinh 4) (2]
tte (rni climh +IMP)
M:r 51-';;ili',ap'3,s53ci?, 4 c, ,;,
^ 3 - f t g l M D « ^ , l * . l S B (1)
Hinh 4. TSff fll^paraISffl Vjio v| umami a i l vd'i sir tiet djch vj
Lirvng dich vi ti6l ra khi chd thi nghidm theo md hlnh cUa Pavlov Sn lOOg thit (miu Kim) vi 100g thit + 2.8g Hi-Me' (hdn hpp 92% ml chlnh + 8% IMP).
TCNCYH 79 (2) - 2012
• JjflkP CHl NGHIEN Cl>U Y HOC Bfen canh dfl, ngm 2007 Zolotarev va cflng
si^ da nghign euu v l kha ngng giCip gia tang si/ti6tdich vi Trong thi nghi0m cCia minh, dng nh$n thiy, khi dua mdt minh glutamate vdi 1 lu-ijng nho (20mL, lOOmMol) vgo dg dgy thi glutamate khflng ed kha ngng kich thieh s y ti^t djch VI, Trong khi dd, n l u glutamate d u a c difa vSo da day eua chfl theo mfl hlnh Pavlov ciing vdi dung dieh dinh d u d n g giau axit amin, du chl vdi mflt lugng nho tuang t y (20mL, lOOmMol) cOng cfl t h i lgm tang s y t i l t djch vj, pepsinogen va axit dg day mflt each rfl rgt (hlnh 5). Bgn cgnh dd, nhdm nghifln edu c6n nhgn thay cam ung cua niflm mgc dg
day vdi glutamate d cac n l n g dd ma khdng v u g t qua nong dfl thflng t h u d n g cua nd trong t h y c pham cfl t h i kich thieh s u gia tang t i l t djch vi, axit da dgy va pepsinogen thflng qua con d u d n g t h i n kinh - nfli t i l t chuygn bigt, Hiflu qua cua glutamate d trong dg dgy d u g e dieu k h i l n mflt p h l n thdng qua s y kleh thich cgc thu t h i 5-HT3 cua tan cung day t h i n kmh p h i vj hudng tam Do dd, nhdm nghidn euu cOng dg dua ra k h u y i n nghj la cd t h i cung c l p cgc dung djch dinh dudng ed b l sung glutamate t u do cho cgc bgnh nhgn ggp v l n d l v l dudng tigu hfla [6],
A ii
AL.
rt ri rt
lt^S<3 Cmls>f>
L - glutamate Ig mflt phan t u smh hge quan trong trong ca the. Ban cgnh nhung chuc nang da biet nhu c h i t kich thich d i n truyin than kinh nao bp, e h l t trung gian eua cgc qua trinh chuyin hda vg kha nang tao vj da dupe bi^t sin, nhung nghign cdu gan dgy cfln k i l n nghj them nhung chdc ngng mdi eua gluta- mate trong c h l dfl gn, Glutamate ed t h i kich thich thu the cua nd d trong da dgy vg t d dd c6 thi sinh ra nhung hoat dflng tai chd ddi vdi chOc ngng cua mflt thflng qua s u hoat hda
% thin kinh p h i vj va cac vCing chuc nang
Hinh 5. Glutamate dud-i dang mi chinh (MSG) (10-100mM, 20mL) Idm gia tang sw tidt axit da ddy. pepsinogen vd dich vi trong da ddy cua chd Pavlov Sw tiit dich ndy dwoc kich thich bdi dung dich dinh du&ng giau axit amin c6 bd sung hoac khdng bd sung gluta- mate vdo trong da day chinh. DO- lieu = trung binh ± do lech chuin S(/ khdc nhau cd y nghla thdng ke giwa dap ung vdi khdu phdn dn (ndng dd MSG = 0) va khdu phdn an cd b6 sung MSG duac ddnh gid bdng ANOVA theo phuang phap Tukey's post-hoc, n = 9.
''p<0.05.
trgn nao, Cd t h i dua ra mflt gia thuyit lg ddng tin higu v l glutamate duac truyin di se bao higu cho nao v l luang protein dugc tieu thu va do dd, viec tieu thu thyc p h i m cd bo sung glutamate cd t h i ldm gia tang lugng dich vi, axit dg day hay peosinogen t i l t ra. D i l u nay sg giup eho qug trinh tigu hda thue pham d i l n ra d l dang han cCing nhu cung co mflt sd chuc nang tgi chfl trong da day
T d nhung nghien cdu v l chuc nang smh ly eua glutamate d trong da day, tfli tin ring viec nghidn cdu vg giai thich toan didn chuc ngng
TAP CHl NGHIEN CO'U Y HpC • smh ly cgc phan tu sinh hpc duge elm dng trong dg day cQng nhu trong Ing tigu hda s§
ed thi giLip chCing ta hilu han v l q u g trlnh dilu hda sy tiflu hfla thyc phim va kilm spgt thfli quen an uing.
O'ng dyng kit qui nhdng nghign cdu dd cCing vdi nhdng nghiin cdu v l cac thy thi dilu hda dac bigt d trpng Ing tigu hda s l md ra cho chOng ta nhilu hudng nghign cdu mdi v l dinh dudng vg phuang thdc mdi d l can thigp vao qua trinh tigu hda td dd cd thi mang din eho ehCing ta nhdng phuang phgp dilu tri mdi,
TAI LIEU THAM K H A O 1. Chaudhari N, Landin AM, Roper SD (2000). A metabotropic glutamate receptor variant functions as a taste receptor Nat Neurosei, 3, 113-119,
^. Kochetkov AM, Shiygin GK, Loran- skaia Tl et al (1992). The use of monosodium glutamate in the combined therapy of patients with atrophic gastritis Vorp Pitan. 5-6; 19-22.
3. Niijima A (2000). Reflex effects of oral, gastrointestinal and hepatoportal glutamgte sensors on vgggi nerve gctivity. J Nutr, 130:
971-973.
4. San Gabriel Ana M., Takami Maekawa, et al (2007). mGluRI in the fundic gignds of rat stomach, 581. 1119-11235.
5. Uneyama H, Niijima A, San Gabriel A, Torii K (2000). Luminal ammo acid sensing in the rat gastnc mucosa. Am J Physiol Gastro- intest Liver Physiol 291, 1163-1170.
6. Zolotarev V, Khropycheva R, Une- yama H, et al (2009). Efect of free Dietary glutamate on gastric secretion in dogs, Inter- national symposium on olfaction and taste Ann. N.Y. Acad. Sci 1170:87-90.
Summary
PHYSIOLOGICAL FUNCTION OF GLUTAMATE IN STOMACH L-glutamate is an important multifunctional essential amino acid involved in intermediary metabolism, excitatory neurotransmission or taste perception. The capability of stimulating umami perception make glutamate and its salts become popular food additives. In addition, evidence from recent studies suggests the new physiological function of glutamate in food digestion in stomach. This review will discuss about the physiolpgical function of glutamate in stomach.
Keywords: physidogical, function, glutamate, umami
TCNCYH 79 (2) - 2012