Does sulfation of gastrin influence gastric acid secretion in man?
To assess the physiologic significance of tyrosine o-sulfation of gastrin in humans, the gastric acid stimulatory potencies of sulfated and non-sulfated human gastrin-17 were compared in six normal young subjects. Sulfated and non-sulfated forms of synthetic human gastrin-17 were infused intravenously in doses from 12.7 to 478 pmol/kg/h. Similar acid secretory responses were observed. The calculated maximal acid response for sulfated gastrin-17 was 35.7 +/- 4.3 mmol/h, and that for non-sulfated gastrin-17 was 39.8 +/- 7.5 mmol/h (mean +/- SEM, NS). The 50% effective dose of sulfated gastrin-17 was 22.2 +/- 6.7 pmol/kg/h, whereas it was 29.3 +/- 5.8 pmol/kg/h for non-sulfated gastrin-17 (NS). Finally, the 50% effective concentration of gastrin in serum was 34.7 +/- 5.0 pmol sulfated gastrin-17/l and 42.5 +/- 11.8 pmol non-sulfated gastrin-17/l (NS). The results show that tyrosine o-sulfation is without significant influence on the gastric acid secretory potency of gastrin in man. Moreover, the results also suggest that sulfated and non-sulfated gastrin-17 in man have similar rates of metabolism.
Cantor
P
P
Dept. of Clinical Chemistry KK, Rigshospitalet, Copenhagen, Denmark.
Petersen
M B
MB
Christiansen
J
J
Rehfeld
J F
JF
D000328:Adult; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005755:Gastrins / Q000008:administration & dosage / Q000494:pharmacology*; D006728:Hormones / Q000494:pharmacology*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D012636:Secretory Rate / Q000187:drug effects*; D013002:Somatomedins / Q000008:administration & dosage / Q000494:pharmacology*; D013431:Sulfates; D014443:Tyrosine
D005755:Gastrins; D006728:Hormones; D013002:Somatomedins; D013431:Sulfates; D014443:Tyrosine; C013550:gastrin 17