Ngakhale insulin isanapezeke, magulu osiyanasiyana a maselo anapezeka m'malo ocheperako pancreatic.
Glucagon yeniyeni yokha idapezedwa ndi Merlin ndi Kimball mu 1923, koma ochepa adachita chidwi ndi zomwe zidapezeka panthawiyi, ndipo patangotha zaka 40 zidadziwika bwino kuti timadzi tambiri timene timagwira mu metabolism ya matupi a ketone ndi glucose.
Komanso, udindo wake ngati mankhwala pakadali pano ndi wopanda ntchito.
Mphamvu zamankhwala
Glucagon ndi tcheni kamodzi polypeptide yopanga zotsalira 29 amino acid. Chidziwitso chofunikira kwambiri pakati pa glucagon ndi mahomoni ena a polypeptide, monga
- chinsinsi
- peptide yoletsa mpweya,
- VIP.
Mitundu ya amino acid yokhudzana ndi mahomoni awa imafanana mu nyama zambiri zomwe zimayamwa komanso chimodzimodzi mu nkhumba, anthu, makoswe ndi ng'ombe; imakhala mahomoni a pancreatic.
Ntchito yakuthupi ndi gawo la glucagon precursors sizinafotokozedwebe. Koma pali lingaliro pokhazikitsidwa ndi magwiridwe antchito a prroglucagon processing kuti onse ali ndi ntchito zapadera.
M'maselo a kanyumba ka kapamba pali ndere zachinsinsi, zomwe zimasiyanitsa chapakati, zopangidwa ndi glucagon, ndi mtanda wakunja wa glycine. Ma cell a L omwe ali m'matumbo amakhala ndi zida zopanga glycine zokha.
Mwambiri, m'maselo amtunduwu wa kapamba palibe enzyme yomwe imasintha glycine kukhala glucagon.
Oxyntomodulin imalimbikitsa adenylate cyclase pomangiriza ku glucagon receptors yomwe ili pa hepatocytes. Ntchito ya peptide iyi pafupifupi 20% ya glucagon.
Mapuloteni ngati glucagon amtundu woyamba amathandizira kutulutsidwa kwa insulin, koma panthawi imodzimodziyo sikukhudza hepatocytes.
Glycine, glucagon-ngati ma peptides ndi oxyntomodulin amapezeka makamaka m'matumbo. Pambuyo pochotsa kapamba, katulutsidwe wa glucagog akupitiliza.
Malamulo apadera
Kubisala kwa glucagon, ndipo kaphatikizidwe kake ndi komwe glucose amayang'anira chakudya, komanso insulin, mafuta acids ndi amino acid. Glucose ndi choletsa champhamvu cha mapangidwe a glucagon.
Imakhudza kwambiri kubisala ndi kaphatikizidwe ka timadzi timeneti tikamamwa pakamwa kuposa momwe timayendetsedwera mkati, izi zimasonyezedwa ndi malangizo ake ogwiritsira ntchito.
Momwemonso, glucose amachita pakubisidwa kwa insulin. Mwambiri, izi zimagwirizanitsidwa ndi mayendedwe am'mimba zamafuta ndipo zimasowa chifukwa cha zovuta zomwe zimapangidwira shuga mellitus (wodalira insulini) kapena pakalibe chithandizo chake.
Palibe mu chikhalidwe cha ma cell. Ndiye kuti, titha kunena kuti kuchuluka kwa glucose pama-cell, kumlingo wina, kumadalira kutseguka kwa insulin katulutsidwe. Mafuta achilengedwe aulere, matupi a somatostatin ndi ketone amathandizanso kubisalira komanso kuchuluka kwa glucagon.
Ma amino acid ambiri amathandizira kubisalira kwa insulin ndi glucagon yonse. Ndiye chifukwa chake akatha kudya zakudya zophatikiza mapuloteni okha, munthu samayamba hypoglycemia yolumikizidwa ndi insulin ndipo ntchito zonse za pancreatic zimapitilizabe kugwira ntchito nthawi zonse.
Monga glucose, ma amino acid amakhudzanso kwambiri mukamamwa pakamwa kusiyana ndi jekeseni. Ndiye kuti, momwe zimagwirira ntchito zimagwirizanitsidwa ndi mahomoni am'mimba. Kuphatikiza apo, katulutsidwe ka glucagon kamayendetsedwa ndi dongosolo lazinthu zamagalimoto.
Kubisala ndi kapangidwe kake ka timadzi timeneti kumakonzedwa ndi kupweteka kwa ulusi wamanjenje wachifundo womwe umayang'anira kubisala kwa ma isanc pancreatic, komanso kuyambitsa kwa sympathomimetics ndi adrenostimulants.
Matenda a metabolism ndi glucagon amatengera mfundo izi:
- Glucagon imawonongeka mwachangu m'chiwindi, m'magazi ndi impso, komanso pazinthu zina.
- Madzi a theka la moyo wawo ndi mphindi 3-6 zokha.
- Hormoni imataya ntchito yake yachilengedwe pamene mapuloteni amafafaniza zotsalira za N-terminal histidine.
Njira yamachitidwe
Glucagon imamangiriza ku cholandirira chapadera chomwe chimapezeka pa membrane wa maselo omwe akufuna. Receptor iyi ndi glycoprotein wina wachilengedwe.
Sizinathebe kuzindikiritsa kapangidwe kake, koma zimadziwika kuti zimamangidwa ndi puloteni ya Gj yomwe imayambitsa adenylate cyclase ndikukhudza kapangidwe kake.
Zotsatira zazikulu za glucagon pa hepatocytes zimachitika kudzera mu cyclic AMP. Chifukwa chosinthidwa kwa gawo la N-terminal la molekyulu wa glucagon, amasinthidwa kukhala agonist pang'ono.
Ndikusunga chiyanjano cha receptor, kuthekera kwake kuyambitsa adenylate cyclase kumakhala kutayika kwambiri. Khalidwe ili ndi mawonekedwe a des-Wake - [Glu9] -glucagonamide ndi [Phen] -glucagon.
Enzyme iyi imatsimikizira kuchuluka kwa ndende ya fructose-2,6-diphosphate, yomwe imakhudza glycogenolysis ndi gluconeogenesis.
Ngati mulingo wambiri wa glucagon ndiwokwera kwambiri ndipo kaphatikizidwe kamothamanga, ndiye kuti inshuwaransi ya 6-phosphofructo-2-kinase / fructose-2,6-diphosphatase imachitika ndipo imayamba kugwira ntchito ngati phosphotase.
Potere, kuchuluka kwa fructose-2,6-diphosphate m'chiwindi kumachepa. Ndi insulin yambiri komanso kuchuluka kwa glucagon, dephosphorylation ya enzyme imayamba, ndipo imagwira ntchito ngati kinase, ikuwonjezera msana wa fructose-2,6-diphosphate.
Pulogalamuyi imabweretsa kutsegula kwa phosphofructokinase - enzyme yomwe imathandizira kutsitsa kwa glycolysis.
Chifukwa chake, ndimatenda a glucagon ambiri, glycolysis amalephereka ndipo gluconeogenesis imakulitsidwa, ndipo ndi insulini yambiri, glycolysis imayambitsidwa. Ketogenesis ndi gluconeogeneis amaponderezedwa.
Kugwiritsa
Glucagon, komanso kapangidwe kake, amafunika kuletsa matenda osokoneza bongo a hypoglycemia pamene sikungatheke kuyendetsa shuga wamkati. Malangizo ogwiritsira ntchito mahomoniwa amafotokoza bwino bwino chilichonse
Izi zimakonda kupezeka mwa odwala matenda ashuga. Komanso timadzi timeneti timagwiritsidwa ntchito pofufuza zinthu zamagetsi popewa mphamvu ya m'mimba. Poterepa, pali njira zina zomwe zimagwiritsidwa ntchito pakugwiritsa ntchito mahomoni.
Glucagon, wogwiritsidwa ntchito ngati mankhwala, amakhala payekha ndi kapamba wa nkhumba kapena ng'ombe. Izi ndichifukwa choti ma amino acid a glucagon mu nyama izi amapezeka mu dongosolo lomwelo. Ndi hypoglycemia, timadzi timene timayendetsedwa ndi intramuscularly, kudzera m'mitsempha kapena m'magulu ochepa a 1 mg
Pazofunikira, kuli bwino kugwiritsa ntchito glucagon ndi njira ziwiri zoyambirira za oyang'anira. Pambuyo mphindi 10, kusintha kumachitika, komwe kumachepetsa chiopsezo cha matenda apakati amanjenje.
Hyperglycemia mothandizidwa ndi glucagon ndiyosakhalitsa, ndipo sangachitike konse ngati malo ogulitsira a glycogen m'chiwindi samakwanira. Pambuyo pakuwongolera matendawo, wodwalayo ayenera kudya kena kake kapena kubaya jekeseni wa m'magazi kuti muchepetse pafupipafupi hypoglycemia Zovuta zomwe zimachitika kawirikawiri m'magazi a glucagon ndikusanza ndi mseru.
- Hormoni iyi imayikidwa musanayambe kafukufuku wamitundu yosiyanasiyana ya X-ray, pamaso pa MRI ndikubwezeretsanso malingaliro kuti apumule minofu yamatumbo ndi m'mimba ndikuwongolera ntchito yawo.
- Glucagon amagwiritsidwa ntchito kuti athetse kupatsirana kwamatenda m'matumbo am'mimba komanso sphincter ya Oddi kapena pachimake diverticulitis.
- Monga gawo lothandiza pochotsa miyala ku ndulu ndikugwiritsa ntchito matumba a Dormia, komanso matumbo am'mimba komanso njira zopewera mu esophagus ndikuwongolera ntchito yawo.
- Glucagon secretion imagwiritsidwa ntchito ngati njira yoyesera yofufuzira pheochromocytoma, chifukwa imayambitsa kutulutsidwa kwa katekisimu ndi maselo a chotupachi.
- Hormoni iyi imagwiritsidwa ntchito pochotsa kugwedezeka, chifukwa imakhala ndi mtima wofikira pamtima. Imathandizanso kwa odwala omwe amatenga beta-blockers, chifukwa adrenostimulants sagwira ntchito zotere.
