Effect of cholera toxin on L-[14C]glycine uptake and intestinal cell enzymes in rabbit.
The uptake of L-[14C]glycine and the activities of intracellular marker enzymes of enterocytes were studied in ligated small intestinal segments of rabbits during experimental cholera induced by intra-intestinal injection of pure cholera toxin (CT). No significant difference was observed in the active uptake of L-[14C]glycine between the CT-injected small intestinal segments and the saline-injected control segments, indicating that there is an intact active transport system for intestinal absorption of L-[14C]glycine during experimental cholera in rabbits. Apart from a significant increase in the activity of a brush border marker enzyme (alkaline phosphatase), there was no significant difference between the activities of marker enzymes for lysosomes (acid phosphate), microsomes (glucose-6-phosphatase), mitochondria (succinate dehydrogenase), and a cytosol enzyme (proteinase) in mucosal homogenates of CT-injected small intestinal segments compared to controls. The finding of an intact mitochondrial marker enzyme together with intact L-[14C]glycine absorption provides a scientific basis for considering the use of glycine and other monoamino monocarboxylic amino acids in "improved" oral rehydration solutions for the treatment of acute diarrhea, including cholera.
Yi-Yi-Myint
Physiology Department, Institute of Medicine, Yangon, Myanmar, Burma.
Khin-Maung-U
Aye-Kyaw
Zin-Thet-Khine
Kyi-Kyi-May
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002772:Cholera Toxin / Q000633:toxicity*; D005998:Glycine / Q000378:metabolism*; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects* / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008871:Microvilli / Q000201:enzymology; D011817:Rabbits
D002772:Cholera Toxin; D000469:Alkaline Phosphatase; D005998:Glycine