Mannose ndi shuga, ngakhale zili ndi mawonekedwe ofanana a molekyulu (C ? H ?? O ?), onsewa ndi ma aldose ndipo ndi C-2 isomers (ie mayendedwe a gulu la hydroxyl pa atomu yachiwiri ya kaboni ndi yosiyana), koma njira zawo zama metabolic ndi ntchito zathupi zimasiyana kwambiri. Zotsatirazi zimapereka kufananitsa kwatsatanetsatane kwa kusiyana kwawo kwa metabolic kuchokera kumawonedwe angapo:

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1. Mayamwidwe m'mimba

Glucose:

Kuyamwa koyenera: Kumayendetsedwa mwachangu ndi SGLT1 (sodium glucose cotransporter 1) m'maselo ang'onoang'ono am'matumbo a epithelial. Kuchuluka kwa mayamwidwe ndikokwera kwambiri (> 95%), komwe kumatha kulowa mwachangu m'magazi ndikukweza shuga m'magazi.

Zimatengera sodium ion gradient. pa

Mannose:

Mayamwidwe osakwanira: makamaka kudzera mu kufalikira kwapang'onopang'ono (mwina kumaphatikizapo zonyamulira mabanja a GLUT monga GLUT5 kapena njira zofananira). Mlingo wa mayamwidwe ndi wotsika kwambiri (pafupifupi 10-20%), ndipo mannose ambiri osayamwa amalowa m'matumbo ndipo amafufutidwa ndi mabakiteriya am'mimba kapena amachotsedwa ndi ndowe.

2. Lowani m'magazi

Glucose:

Pambuyo pa kuyamwa, imalowa mwachindunji mumayendedwe a portal mtsempha, zomwe zimapangitsa kuchuluka kwa shuga m'magazi.

Mannose:

Kuchuluka kwa mayamwidwe kumakhala kochepa, ndipo kuchuluka kwa mannose m'magazi kumakhala kotsika kwambiri (kusala kudya kwanthawi zonse m'magazi a plasma ndi pafupifupi 50 μ mol / L, kutsika kwambiri kuposa 4-6 mmol / L ya shuga). Kuwongolera m'kamwa kwa mannose sikuyambitsa kusinthasintha kwakukulu kwa shuga m'magazi.

3. Njira zoyambira za metabolic ndi minyewa

Glucose:

Kudalira insulini: Kutengeka kwa shuga mu minofu ndi adipose kumadalira kwambiri chizindikiro cha insulin (kudzera mwa GLUT4 transporter).

Hexokinase/Glucokinase: Ikalowa m'maselo, imakhala phosphorylated ndi hexokinase (HK) (systemic tissue) kapena glucokinase (GK) (chiwindi) kupita ku glucose-6-phosphate (G6P). Ichi ndiye gawo lalikulu la metabolism ya shuga.

Mannose:

Osadalira insulini: Kutenga minofu sikudalira insulini.

Mannokinase (MK): Imakhala ndi phosphorylated ndi mannokinase m'chiwindi (yokhala ndi kachulukidwe kakang'ono m'magulu ena monga impso) kupita ku mannose-6-phosphate (Man-6-P). Ichi ndi gawo lofunikira kwambiri lochepetsa kuchepa kwa mannose metabolism.

Phosphomannose isomerase (PMI): Man-6-P imasinthidwa kukhala fructose-6-phosphate (F6P) ndi phosphomannose isomerase. F6P ndi chinthu chapakatikati cha njira ya glycolysis.

4. Njira zazikulu za metabolic

Glucose:

Mphamvu ya Glycolysis: G6P imatha kulowa munjira ya glycolysis kuti ipange mphamvu (ATP).

Kaphatikizidwe ka Glycogen: Kaphatikizidwe ndi kasungidwe ka glycogen m'chiwindi ndi minofu.

Njira ya pentose phosphate: imapanga NADPH ndi ribose-5-phosphate (yogwiritsidwa ntchito pochepetsa biosynthesis ndi nucleotide synthesis).

Kuphatikizika kwamafuta: Kuchuluka kwamafuta kukakhalapo, kumasinthidwa kukhala mafuta.

Mannose:

Kutembenuka kukhala glycolytic intermediates: Pambuyo PMI kutembenuka F6P, akhoza kulowa glycolytic njira (gawo lomaliza likhoza kusandulika shuga kapena oxidized kwathunthu kuti apereke mphamvu).

Glycosylation precursor: Ntchito yake yayikulu ndikugwira ntchito ngati gulu loyambira la shuga popanga unyolo wa shuga wolumikizidwa ndi N! Man-6-P ikhoza kusinthidwa kukhala GDP mannose mu vivo, kukhala wopereka mwachindunji zotsalira za mannose mu glycoproteins ndi glycolipids.

Glycosylation: Mannose ndi gawo lofunikira la chain oligosaccharide mu protein N-linked glycosylation modification (monga Man ? GlcNAc ?). Izi zimachitika mu endoplasmic reticulum ndi zida za Golgi, ndipo ndizofunikira pakupindika kwa mapuloteni, kukhazikika, kukhazikika, ndi magwiridwe antchito (monga ma antibodies, zolandilira mahomoni, ndi ma cell adhesion molecule).

Kusintha kukhala shuga/glycogen: Kuchita bwino kumakhala kochepa, ndipo njira zina za F6P zosinthika za glycolysis zimapanga G6P, yomwe imasinthidwa kukhala shuga kapena glycogen, koma chothandizira chake chimakhala chochepa.

5. Zotsatira pa glucose wamagazi ndi insulin

Glucose:

Shuga wokwera kwambiri: ndiye gwero lalikulu la shuga.

Kukondoweza kwambiri kwa katulutsidwe ka insulini: Ma cell a pancreatic beta amazindikira mwachindunji kuchuluka kwa shuga m'magazi ndikutulutsa insulin.

Mannose:

Pafupifupi sizimakhudza shuga wamagazi: zimatenga pang'ono, zimagaya popanda kupanga shuga, ndipo sizidalira insulin.

Kusalimbikitsa katulutsidwe ka insulini: kusowa kwamphamvu zolimbitsa thupi zamagazi.

6. Kusiyana kwakukulu mu ntchito zakuthupi

Glucose:

Ntchito yaikulu: Gwero lalikulu la mphamvu zofulumira (makamaka ubongo, minofu, ndi maselo ofiira a magazi), kusunga shuga m'magazi a homeostasis.

Mannose:

Ntchito yapakati: chinthu chofunikira cha kalambulabwalo wa glycosylation biosynthesis, chothandizira kapangidwe kake ndi ntchito ya glycoproteins ndi glycolipids (kuzindikira ma cell, kutulutsa chizindikiro, chitetezo chokwanira, kupindika kwa mapuloteni, ndi zina).

Ntchito yachiwiri: Pewani matenda a mkodzo (potsekereza kumatira kwa bakiteriya).

7. Kusiyana kwa ntchito zachipatala

Glucose:

Zowonjezera mphamvu (kulowetsedwa), chithandizo cha hypoglycemic, kuyesa kulolerana kwa glucose.

Mannose:

Kupewa matenda obweranso mkodzo (makamaka kulunjika Escherichia coli) komanso kuchiza matenda osowa amtundu wa glycosylation (monga kuchepa kwa CDG Ib MPI).