Cau 24: cac hormon: GH, ACTH, TSH : ban chat, tac dung, dieu hoa bai tiet va UDLS

a) hormon phat trien co the GH (hGH)

*) ban chat hoa hoc: GH la 1 ptu pr chua 191 acid amin trong moi chuoi don va co trong lg ptu la 22005 dvc.

*) tac dung: GH lam phat trien tat ca cac mo co knang tang truong trong co the. No vua lam tang kick thuoc Tb vua lam tang tang qtrinh phan chia TB do do lam tang trong lg co the, lam tang kick thuoc cac phu tang.

- kick thick mo sun va xuong phat trien:

+) tang lang dong pr o cac TB sun va TB tao xuong

+) tang toc do sinh san cac TB sun va te bao tao xuong

+) tang chuyen cac TB tao sun thanh cac TB tao xuong

- kick thick sinh tong hop pr :

+) tang vc acid amin qua mang TB

+) tang qtrinh sao chep ADN cua nhan TB de tao ARN

+) tang qtrinh dich m• ARN de lam tang tong hop pr tu ribosom

+) giam qtrinh thoai hoa pr va acid amin

- tang tao nang lg tu nguon lipid:

+) tang giai phong acid beo tu cac mo du tru, do do lam tang Cm acid beo trong mau.

+) chinh vi td nay ma ng ta coi td huy dong lipid cua GH la 1 trong nhung td qtrong nhat nham tiet kiem pr de dung no cho su phat trien co the

- tac dung len chuyen hoa glucid:

+) giam glucose cho muc dich sinh nang lg

+) tang du tru glycogen o TB

+) giam vc glucose vao TB va tang Cm glucose trong mau

+) tang bai tiet insulin: Cm cua glucose trong mau tang duoi td cua GH d• kick thick tuyen tuy noi tiet bai tiep insulin, dong thoi chinh GH cung co tac dung kick thick truc tiep TB beta cua tuyen tuy

*) dieu hoa bai tiet:

- vung duoi doi: GH dc bai tiet duoi su dkhien gan nhu hoan toan cau hai hormon vung duoi doi la GHRH va GHIH

- Somatostatin la 1 hormon tai cho do nhieu vung n•o va dg tieu hoa bai tiet cung co td uc che bai tiet GH

- Cm glucose giam trong mau, Cm acid beo trong mau giam, thieu pr nang va keo dai se lam tang bai tiet GH

- Tinh trang stress, chan thuong, luyen tap gang suc se lam tang bai tiet GH

- o ng vn, Cm GH trong mau cuong ron tre so sinh la 28,38 +- 10,03 ng/ml, ng truong thanh la 3,94 +- 2,09 ng/ml

b) hormon kick thick tuyen giap: TSH

*) ban chat hoa hoc: TSH la 1 glycoprotein, co trong lg ptu 28000

*) tac dung:

- tac dung len ctruc tuyen giap:

+) tang so lg va kick thuoc TB tuyen giap trong moi nang giap

+) tang bien doi cac TB nang giap tu dang khoi sang dang tru( dang bai tiet)

+) tang he thong phat trien mao mach cau tuyen giap

- tac dung len cnang tuyen giap

+ tang hd bom ion do do lam tang knang bat ion cua TB tuyen giap.

+ tang gan iot vao tyrosin de tao hormon tuyen giap

+ tang phan giaI thyroglobulin dc du tru trong long nang de giaI phong hormon tuyen giap vao mau va do do lam giam chat keo trong long nang tuyen.

*) dieu hoa bai tiet:

o ng vn bthg Cm TSH o tre em so sinh ( mau cuong ron) la 6,24+- 2,96 va ng trg thanh ( 16 - 60 tuoi) la 2,12 +- 0,91 mU/l

muc bai tiet TSH cua tuyen yen chiu su dkhien tu tren xuog cua TRH vung duoi doi va chiu su dieu hoa ngc cua tuyen dich la tuyen giap

- neu nong do TRH vung duoi doi tang thi tuyen yen se bai tiet nhieu TSH va ngc lai neu TRH giam thi Cm TSH giam. khi he thong cua duoi doi - yen bi ton thg, muc bai tiet TSH cua tuyen yen co thea giam toi mu = 0

- Nong do hormon tuyen giap anh huong den su bai tiet TSH cuat tuyen yen theo co che dieu hoa ngc am tinh va duong tinh

c) hormon kick thick tuyen vo thuong than: ACTH

*) Ban chat hoa hoc: ACTH la 1 ptu polypeptid lon gom 39 acid amin

*) tac dung

- Td len cau truc vo thg than: ACTH lam tang sinh TB tuyen vo thuong than db la TB cua lop bo va lop luoi, la nhung TB bai tiet cortisol va androgen do do cac tuyen mo to. Thieu ACTH tuyen vo thuong than se bi teo lai

- Td len cnang vo thuong than: ACTH co td kick thick vo thg than tong hop va bai tiet hormon do hoat hpa cac enzym proteinlinase A la enzym thuc day chang dau tien cua qtrinh sinh tong hop hormon vo thg than

- Td len n•o: ACTH co vai tro lam tang qua trinh hoc tap va tri nho, tang cam xuc so h•i.

- Td len TB sac to: ACTH kick thick TB sac to sx sac to melanin roi phan tan sac to nay tren be mat bieu bi da. Thieu ACTH se lam cho da ko co sac to( ng bach tang). ngc lai thua ACTH lam cho da co nhung mang sac to.

*) Dieu hoa bai tiet:

- Do nong do CRH cua vung duoi doi qdinh, khi Cm CRH tang thi ACTH dc bai tiet nhieu ngc lai khi vang mat CRH tuyen yen chi bai tiet 1 lg rat it ACTH

- Do tac dung Dhoa ngc am tinh va duong tinh cua cortislo

- Cm ACTH con dc dhoa theo nhip sinh hoc. Trong ngay, Cm ACTH cao nhat vao khoang 6 - 8h sang sau do giam dan va thap nhat vao khoang 23h roi lai tang dan ve sang.

- binh thg nong do ACTH trong huyet tg vao buoi sang khoang 10 - 50pg/ml khi bi stress nong do tang rat cao co the len toi 600pg/ml. o ng vn truong thanh( lay mau luc 8h30 sang tren nam khoe manh) Cm ACTH la 9,7773 +- 4,599 pg/ml.