Nature of the enhancement of the protective qualities of gastric mucus by sucralfate.
The effects of intragastric administration of an antiulcer drug, sucralfate, on the content, composition and physical properties of the mucus component of gastric mucosal barrier were investigated. The experiments were conducted with two groups of rats in which one group received twice daily for five consecutive days a dose of 100 mg sucralfate, while the control group received daily doses of saline. The animals were sacrificed 16 h after the last dose, their stomachs dissected and the mucosa subjected to measurements of the adherent mucus gel dimension and mucin content, evaluation of its viscosity, H+ retardation capacity and hydrophobicity, and analysis of its components and molecular form distribution of elaborated mucin. The results revealed that sucralfate elicited only a minor (8%) increase in mucus gel dimension, while sulfo- and sialomucin contents of the gel increased by 63 and 81%, respectively. The changes in mucus gel mucin content with sucralfate were accompanied by a slight (9.5%) increase in mucus H+ retardation capacity, 1.9-fold increase in viscosity, and a 60% increase in the gel hydrophobicity. Chemical analyses indicated that the mucus elaborated in the presence of sucralfate exhibited 14% lower protein content and 62% higher content of carbohydrate than that of control, displayed similar levels of total lipids and covalently bound fatty acids, but its neutral lipid content was significantly higher. Furthermore, the gastric mucus of the sucralfate group showed a marked increase in the proportion of the high-molecular-weight form of mucin, while the low-molecular-weight form predominated in the control group. The results indicate that the protective qualities of sucralfate lie mainly in its ability to enhance the gastric mucus gel viscosity, hydrophobicity, content of mucin and its proportion in the high-molecular-weight form.
Slomiany
B L
BL
Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark.
Piotrowski
J
J
Okazaki
K
K
Grzelinska
E
E
Slomiany
A
A
D000818:Animals; D001834:Body Water / Q000378:metabolism; D005752:Gastric Mucins / Q000032:analysis; D005753:Gastric Mucosa / Q000187:drug effects*; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D013392:Sucralfate / Q000494:pharmacology*; D014783:Viscosity
D005752:Gastric Mucins; D013392:Sucralfate