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.
Physiology Department, Institute of Medicine, Yangon, Myanmar, Burma.
Yi-Yi-Myint
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