An osmotic-sensitive taurine pool is localized in rat pancreatic islet cells containing glucagon and somatostatin
Departments of 1 Physiology and 2 Biochemistry, Faculty of Medicine, Universidad Complutense, 28040 Madrid; and 3 Department of Investigation, Hospital Ramón y Cajal, 28034 Madrid, Spain Previous reports have dealt with the hypoglycemic properties of taurine and its effects on insulin secretion b...
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Published in | American journal of physiology: endocrinology and metabolism Vol. 281; no. 6; pp. E1275 - E1285 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.12.2001
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Subjects | |
Online Access | Get full text |
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Summary: | Departments of 1 Physiology and 2 Biochemistry,
Faculty of Medicine, Universidad Complutense, 28040 Madrid; and
3 Department of Investigation, Hospital Ramón y Cajal,
28034 Madrid, Spain
Previous reports have dealt with the hypoglycemic
properties of taurine and its effects on insulin secretion by adult and fetal isolated islets. We have studied the presence and cellular distribution of taurine in rat islets, the conditions to evoke its
release, and its possible modulatory action on insulin secretion. We
localized taurine by techniques of double immunolabeling in most
glucagon-positive cells and in some somatostatin-positive cells,
whereas insulin-positive cells were not labeled with the taurine
antibody. Although high-glucose stimulation did not evoke any taurine
release, a hyposmotic solution (17% osmolarity reduction) induced a
specific phasic release of taurine and GABA (34 and 52% increase on
their basal release rate). On the other hand, taurine (10 mmol/l)
application slightly reduced the second phase of insulin secretion
induced by glucose stimulation. In conclusion, taurine is highly
concentrated in glucagon-containing cells of the islet periphery. It is
not liberated by glucose stimulation but is strongly released under
hyposmotic conditions. All of these data suggest that taurine plays an
osmoregulatory role in -cells.
taurine distribution; -aminobutyric acid release; amino acid
content; insulin secretion; immunocytochemistry |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0193-1849 1522-1555 |
DOI: | 10.1152/ajpendo.2001.281.6.E1275 |