- DDi vdi mot sDthuDc chi sau khi chuyen hoa mdi cotac dung hoac tang dQc tinh thi cam ling enzym lam tang tac dung hoac tang dQc tinh cua thuoc.
THUOC TAc DVNG TREN He THAN KINH TRUNG VdNG
He THAN KINH TRUNG VdNG
D~ICUaNG
1.cAc CHAT TRUNG GIANDANTRVYENCVAHt THAN KINH TRUNG UdNG
Hien nay co khoang 40 chat d~n truyen than kinh, chia 2 nhom (tom t:it trong bang 3.1).
• Nhom cophiin. tit nho (diu true kh6ng pep tid)
Cac chat trung gian d~n truyen loai co phan tli nho la nhung chat co tac dung nhanh, gay ra phan IOncac dap trng cap cua h~ than kinh nhu truyen cac tin hieu cam giac tdi nao va tin hieu v~n d9ngtit nao ra ngoai vi, g6m cac chat acetylcholin, dopamin, noradrenalin, serotonin, cac amin kich thich (acid glutamic va acid aspartic), cac amin uc che (GABAva glycin).
Acetylcholin: la chat trung gian d~n truyen, tac dung thong qua receptor MI,M2va N d than kinh trung uong.
Noradrenalin: la chat trung gian anh hudng tdi su hoc hoi, tri nhd va chu ky thuc ngu, Tac d9ng cua noradrenalin thong qua receptor U2va f32d than kinh trung uong.
Dopamin: la chat trung gian d~n truyen uc che tai he thong than kinh Ian toa, la mdt catecholamin co vai tro quan trong d than kinh trung uong, lien quan nhieu de'n qua trinh hung phan va uc che tam th~n. Tac dVng cua dopamin thong qua cac receptor dopaminergic. Cac thu6c huy h~ dopaminergic lam giam tri~u chung kich d9ng, hoang tUdngva lam tang tri~u chung am tinh nhu tu duy ch~m, kho khan, cam xuc kho, l~nh. Ngu<;jcl~i, thu6c cUdng h~ dopaminergic lam tang tri~u chung tam th~n hung cam.
Serotonin (5-hydroxytryptamin): la chat d~n truygn lo~i uc che',co vai tro trong giac ngu, tie'p nh~n cam giac dau, tr~m cam, tinh dvc. Tac d9ng thong qua receptor serotoninergic. Thu6c ch6ng tr~m cam co tac dVng ngan can thu h6i serotonin. Ngoai ra, con anh hUdngWi s,! digu hoa than nhi~t va lien quan den phong thich hormon tuyen yen.
Acid glutamic va acid aspartic: la cac amin d~n truygn lo~i kich thich, tac dVng chu ye'u thong qua receptor N- methyl- d- aspartat (NMDA).Receptor nay bi uc che bdi ketamin.
GABA va glycin: GABA la chat d~n truyen uc che quan trong dnao va tuy song. Cac thuoc an than gay ngu d~n xuat benzodiazepin va barbiturat,
thuoc gay me tao thuan lei cho d~n truyen GABA do g:1n vao receptor
GABAA' Cac chat gay co giat nhu pentylentetrazol, picrotoxin la chat d6i khang voi GABA.
Glycin Ia chat dan truyen trc che' chu yeu d tuy song. Cac thuoc uc che' glycin se gay tinh trang kich thich (strychnin).
• Nhom cophiin tit l/m. (diu true peptid)
Cac chat trung gian d~n truyen ph an tli Ion thuong duoc bai tie't it han so voi loai ph an tli nho, Btl.lai tac dung cua no manh han hang ngan lftn va tac dung keo dai han. Chuc nang cua nhom peptid mdi duoc nghien ciru gftn day va chua dfty duoM9t so'peptid duoc biet de'n la: endorphin, enkephalin, dynorphin, vasopressin, chat P...
Bang 3.1. T6m tat cac chat trung gian dan truyen ella h~ than kinh trung LIang
Chat d~n
Vi trl giai ph~u Receptor va chat Chat doi khimg Cd che
truyen chu v~n
Acetylcholin Toan h$ thong M1:muscarin Pirenzepin, atropin Kich thich: iIP3,
DAG,iK+ M2:muscarin, Atropin, uc che:iAMPv, i
bethanechol methoctramin K+
Nelron van N: nicotin Dihydro ~- Kich thich: ication
d(mg- synap te erythroidin, a-
bao Ren- shaw bungarotoxin
Dopamin Toan h$ thong D1:SKF 38393 Phenothiazin Uc che (?):iAMPv
D2:quinpirol Phenothiazin Uc che:iAMPv
bromocriptin Butyrophenon
GABA Nelron trung GABAA: muscimol Picrotoxin. Uc che: iCI-
gianbtuy song Bicucullin
GABAs: baclofen 2-0H saclofen Uc che (trLlac CGP 35348 synap): iCa++ CGP 55845 Dcche (sau synap):
iK+
Glutamat Nelron trung N-methyl-D- 2-amino-5- Kich thich: t cation gian toan h$ aspartat (NMDA): phosphonovalerate,
thong NMDA CPP, MK801
AMPA:AMPA CNQX, GYKI Kich thich: iCa++ 52466
Kainat: kainat, CNQX acid domoic
Metabotropic: MCPG Ucche (tnroc
ACPD, quisqualat synap): ,1.Ca++
Kfch thfch:t IP3, DAG,,1. K+ Glycin Noren trung Taurin, p-alanin Strychnin Uc che: t cr
gian tuy
Serotonin Nao giCta cau" 5- HT1A: LSD, 8- Metergolin, Uc che: ,1.AMPv, t
(5- HT) nao OH-DPAT spiperon K+
5- HT2A: LSD, Ketanserin Kfch thfch: t IP3,
DOB DAG,,1. K+