Linked Life Data

9196560

Source:http://linkedlifedata.com/resource/pubmed/id/9196560

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1997-9-11
pubmed:abstractText
Since experimental diabetes in rats and mice is associated with impairment of several aspects of thyroid function, we determined glucose and amino acid uptake in vitro by isolated thyroid glands from normal and streptozotocin-diabetic rats. Adult male Wistar rats weighing 150-200 g were used. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) and after five days only rats with blood glucose levels higher than 250 mg/dl were used. The thyroid glands were preincubated in Krebs-Ringer bicarbonate buffer in the presence or absence of insulin (0.7 nM to 7 muM) for 90 min and then incubated with the same concentration of the hormone or its vehicle plus 0.2 microCi of [1-14C]-2-deoxy-D-glucose ([14C]DG) or [1-14C] methylaminoisobutyric acid ([14C]MeAIB) for 15 to 180 min. The uptake of [14C]DG or [14C]MeAIB by the thyroid glands of normal rats increased as a function of incubation time, and the presence of insulin (7 microM) induced a significant increase of labelled DG from 3.30 +/- 0.11 to 4.16 +/- 0.12 and of labelled meAIB from 1.79 +/- 0.06 to 3.10 +/- 0.17 tissue/medium ratio (T/M) and after 45 min of incubation. The lowest concentration of insulin that increased both [14C]DG and [14C]MeAIB transport was 7 nM. Thyroid glands from STZ rats exhibited lower basal values of [14C]DG (4.03 +/- 0.11 T/M) or [14C]MeAIB uptake (1.05 +/- 0.05 T/M) than glands from normal rats (4.62 +/- 0.13 and 1.70 +/- 0.08 T/M, respectively). Insulin produced a stimulatory effect on the transport of both substrates in STZ rats. However, the maximal stimulating concentration of the hormone did not restore [14C]DG and [14C]MeAIB uptake to control values (4.89 +/- 0.17 in STZ rats versus 5.44 +/- 0.17 T/M in controls for [14C]DG, and 1.51 +/- 0.11 in STZ rats versus 2.19 +/- 0.10 T/M in controls for [14C]MeAIB). These results indicate that insulin exerts a direct action on the thyroid gland, and its absence or reduction affects thyroid metabolism, contributing, at least in part, to the abnormality in thyroid function associated with diabetes mellitus.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0100-879X
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1549-55
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Decreased basal and acute insulin-stimulated effect on the uptake of glucose and amino acid in vitro by thyroid glands from streptozotocin-diabetic rats.
pubmed:affiliation
Departamento de Fisiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't