I-Mannose kanye neglucose, nakuba zinefomula yamangqamuzana efanayo (C ? H ?? O ?), zombili ziyi-aldose futhi ziyi-C-2 isomers (okungukuthi indlela yeqembu le-hydroxyl ku-athomu yesibili ye-carbon ihlukile), kodwa izindlela zabo ze-metabolic kanye nemisebenzi ye-physiological ihluke kakhulu. Okulandelayo kunikeza ukuqhathanisa okuningiliziwe komehluko wabo we-metabolic emibonweni eminingi:

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1. Ukumuncwa kwamathumbu

IGlucose:

Ukumuncwa okusebenzayo: Kuthuthwa kakhulu nge-SGLT1 (i-sodium glucose cotransporter 1) kumaseli amancane we-epithelial wamathumbu. Izinga lokumuncwa liphezulu kakhulu (>95%), elingangena ngokushesha egazini futhi linyuse ushukela wegazi.

Kuncike ku-sodium ion gradient. .

I-Mannose:

Ukumuncwa ngendlela engafanele: ikakhulukazi ngokusabalalisa okwenziwa lula (okungenzeka okubandakanya izithuthi zomndeni ze-GLUT ezifana ne-GLUT5 noma amashaneli afanayo). Izinga lokumunca liphansi kakhulu (cishe u-10-20%), futhi iningi le-mannose engamuncwanga ingena ekoloni futhi ivutshelwe amagciwane amathumbu noma ikhishwe ngendle.

2. Ngena emgudwini wegazi

IGlucose:

Ngemuva kokumuncwa, ingena ngqo ku-portal vein circulation, okubangela ukwanda okusheshayo kwamazinga kashukela egazini.

I-Mannose:

Inani lokumunca liphansi, futhi ukugcwala kwemannose egazini kuphansi kakhulu (ukugxila kwe-plasma okuzila ukudla okujwayelekile cishe ku-50 μ mol/L, kungaphansi kakhulu kuka-4-6 mmol/L weglucose). Ukuphathwa ngomlomo kwe-mannose akubangeli ukushintshashintsha okuphawulekayo kumazinga kashukela egazini.

3. Izinyathelo zokuqala zokuthathwa kwezicubu kanye ne-metabolism

IGlucose:

Okuncike ku-insulin: Ukuthatha izicubu zezicubu ze-adipose kwe-glucose kuncike kakhulu ekusayinweni kwe-insulin (nge-GLUT4 transporter).

I-Hexokinase/Glucokinase: Ngemva kokungena kumaseli, i-phosphorylated nge-hexokinase (HK) (izicubu zesistimu) noma i-glucokinase (GK) (isibindi) ibe yi-glucose-6-phosphate (G6P). Leli yi-molecule eyinhloko ye-sugar metabolism.

I-Mannose:

Akuncikile ku-insulin: Ukuthathwa kwezicubu akuncikile ku-insulin.

I-Mannokinase (MK): I-phosphorylated ikakhulukazi i-mannokinase esibindini (enenani elincane kwezinye izicubu ezifana nezinso) kuya ku-mannose-6-phosphate (Man-6-P). Lesi isinyathelo esibalulekile esinciphisa izinga kumetabolism ye-mannose.

I-Phosphomannose isomerase (PMI): I-Man-6-P iguqulelwa ku-fructose-6-phosphate (F6P) nge-phosphomannose isomerase. I-F6P iwumkhiqizo omaphakathi wendlela ye-glycolysis.

4. Izindlela eziyinhloko ze-metabolic

IGlucose:

I-Glycolysis energy supply: I-G6P ingangena endleleni ye-glycolysis ukukhiqiza amandla (ATP).

I-Glycogen synthesis: Ukuhlanganiswa nokugcinwa kwe-glycogen esibindini nasemisipha.

Indlela ye-pentose phosphate: ikhiqiza i-NADPH ne-ribose-5-phosphate (esetshenziselwa ukunciphisa i-biosynthesis kanye ne-nucleotide synthesis).

Ukuhlanganiswa kwamafutha: Uma kukhona ngokweqile, aguqulwa abe ngamafutha.

I-Mannose:

Ukuguqulelwa ku-glycolytic intermediate: Ngemva kokuguqulwa kwe-PMI ku-F6P, ingangena endleleni ye-glycolytic (ingxenye yokugcina ingaguqulelwa ku-glucose noma i-oxidized ngokuphelele ukuze kutholakale amandla).

I-Glycosylation precursor: Umsebenzi wayo oyinhloko ukusebenza njengeqembu lokuqala likashukela lokuhlanganisa amaketanga kashukela axhunywe ku-N! I-Man-6-P ingabuye iguqulelwe ibe yi-GDP mannose ku-vivo, isebenze njengomnikezeli oqondile wezinsalela ze-mannose kuma-glycoprotein nama-glycolipids.

I-Glycosylation: I-Mannose iyingxenye eyinhloko yeketango le-oligosaccharide eliyinhloko ekuguqulweni kwe-glycosylation ye-protein N (njenge-Man ? GlcNAc ?). Le nqubo yenzeka ku-endoplasmic reticulum kanye ne-Golgi apparatus, futhi ibalulekile ekugoqeni amaprotheni, ukuzinza, ukwenziwa kwasendaweni, kanye nokusebenza (njengamasosha omzimba, ama-hormone receptors, nama-molecule e-adhesion cell).

Ukuguqulelwa ku-glucose/glycogen: Ukusebenza kahle kuphansi, futhi eminye imizila ye-F6P ehlehliswayo ye-glycolysis ikhiqiza i-G6P, ebese iguqulelwa ku-glucose noma i-glycogen, kodwa umnikelo mncane.

5. Imiphumela ku-glucose yegazi ne-insulin

IGlucose:

Ushukela wegazi ophakeme kakhulu: ungumthombo oyinhloko kashukela egazini.

Ukugqugquzelwa okukhulu kokukhiqizwa kwe-insulin: Amaseli e-beta e-pancrea ezwa ngokuqondile ukwanda kashukela egazini futhi akhiphe i-insulin.

I-Mannose:

Cishe ayithinti ushukela wegazi: imunca kancane, igaya umzimba ngaphandle kokukhiqiza i-glucose, futhi ayinciki ku-insulin.

Ayikukhuthazi ukukhiqizwa kwe-insulin: ayinazo izimpawu ezisebenzayo zokuvuselela ushukela wegazi.

6. Umehluko oyinhloko emisebenzini yomzimba

IGlucose:

Umsebenzi oyinhloko: Umthombo oyinhloko wamandla asheshayo (ikakhulukazi ubuchopho, imisipha, namangqamuzana egazi abomvu), ukugcina i-homeostasis kashukela egazini.

I-Mannose:

Umsebenzi oyinhloko: Into eyisandulela eyinhloko ye-glycosylation biosynthesis, esekela ukwakheka nokusebenza kwama-glycoprotein nama-glycolipids (ukubonwa kweseli, ukudluliselwa kwesignali, ukungatheleleki, ukugoqa amaprotheni, njll.).

Umsebenzi wesibili: Vimbela izifo zomgudu womchamo (ngokuvimbela ukunamathela kwebhaktheriya).

7. Umehluko wesicelo somtholampilo

IGlucose:

Ukwengezwa kwamandla (ukufakwa), ukwelashwa kwe-hypoglycemic, ukuhlolwa kokubekezelela ushukela.

I-Mannose:

Ukuvinjelwa kwezifo eziphindelelayo zomgudu womchamo (ikakhulukazi kuqondiswe ku-Escherichia coli) kanye nokwelashwa kwezifo ezithile ezingavamile zofuzo ze-glycosylation (ezifana nokushoda kwe-CDG Ib MPI).