Linked Life Data

6277985

Source:http://linkedlifedata.com/resource/pubmed/id/6277985

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1982-5-27
pubmed:abstractText
A patient with type I pseudohypoparathyroidism was found to have mild hypothyroidism. The patient had an elevated basal TSH level and an exaggerated TSH response to TRH. There was no goiter despite increased TSH levels, and the 131I thyroidal uptake was low before and after exogenous TSH administration. These studies suggested that the patient might have partial resistance to TSH. The binding of radioiodinated TSH to thyroid membranes obtained by biopsy was next studied. The displacement of iodinated TSH by unlabeled TSH was found to be identical to that in normal control membranes. The adenylate cyclase stimulation by a supramaximal dose of TSH, however, was blunted (120.1 +/- 11.5 vs. 387.2 +/- 40.3 pmol cAMP/min/mg protein), while basal and NaF-stimulated activities were quite similar to the activities in normal membranes. These findings suggested a lack of signal transmission between the TSH receptor and the catalytic unit. Incubation of control membranes with TSH and GTP resulted in a synergistic effect on the adenylate cyclase activity. This was not found with the patient's membranes and suggested that the coupling failure was due to a defective guanine nucleotide regulatory protein. We conclude that in this case of type I pseudohypoparathyroidism, the associated mild primary hypothyroidism was due to a partial TSH refractoriness caused by a coupling defect between the TSH receptor and adenylate cyclase. This observation suggests that a common pathogenetic mechanism might underly type I pseudohypoparathyroidism and its associated hypothyroidism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1028-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Coupling defect of thyrotropin receptor and adenylate cyclase in a pseudohypoparathyroid patient.
pubmed:publicationType
Journal Article, In Vitro, Case Reports