Ganong's Review of Medical Physiology, 23rd Edition

444 SECTION V Gastrointestinal Physiology

TABLE 26–6. Structures of some of the hormonally active polypeptides secreted by cells in the human
gastrointestinal tract.a

Gastrin Family GIP Secretin Family Other Polypeptides

CCK Gastrin

39 34 Glucagon Secretin VIP Motilin Substance P GRP Guanylin

aHomologous amino acid residues are enclosed by the lines that generally cross from one polypeptide to another. Arrows indicate points of cleavage to form smaller variants.
Tys, tyrosine sulfate. All gastrins occur in unsulfated (gastrin I) and sulfated (gastrin II) forms. Glicentin, an additional member of the secretin family, is a C-terminally extended
relative of glucagon.

Tyr Tyr His His His Phe Arg Val Pro

elI reSalA reSreS orPlaV orP nsA

Gln Glu Gln Asp Asp Pro Lys Leu Thr

Gln Gly Gly Gly Ala Ile Pro Pro Cys

Ala Thr Thr Thr Val Phe Gln Ala Glu

Arg (pyro)Glu Phe Phe Phe Phe Thr Gln Gly Ile

Lys Leu Ile Thr Thr Thr Tyr Phe Gly Cys

Ala Gly Ser Ser Ser Asp Gly Phe Gly Ala

Pro Pro Asp Asp Glu Asn Glu Gly Thr Tyr

Ser Gln Tyr Tyr Leu Tyr Leu Leu Val Ala

Gly Gly Ser Ser Ser Thr Gln Met-NH 2 Leu Ala

Arg Pro Ile Lys Arg Arg Arg Thr Cys

Met Pro Ala Tyr Leu Leu Met Lys Thr

Ser His Met Leu Arg Arg Gln Met Gly

Ile Leu Asp Asp Glu Lys Glu Tyr Cys

Val Val Lys Ser ylG nlG syL orP

Lys Ala Ile Arg Ala Met Glu Arg

Asn Asp His Arg Arg Ala Arg Gly

Leu Pro Gln Ala Leu Val Asn Asn

nlG reS nlGnlG syLnlG syL siH

syLnsA psApsA syLgrA ylG prT

Leu Lys Phe Phe Leu Tyr Gln Ala

Asp Gln Va laVl ueLueL aVl

Pro Gly Asn Gln Gln Ans lGy

Ser Pro Trp Tpr reSylG iHs

siH prT ueLueL elIueL ueL

Arg Leu Leu Met Val-NH 2 Leu Met-NH 2

Ile Glu Ala Asn Asn-NH 2

Ser Glu Glu Thr

Asp Glu Lys

Arg Glu Gly

Asp Glu Lys

Tys Ala Lys

Met Tys Asn

Gly Gly Asp

Trp Trp Trp

Met Met Lys

Asp Asp His

Phe-NH 2 Phe-NH 2 Asn

Ile

Thr

Gln

→

→

→

→

→

→

→