Dual activation by thyrotropin of the phospholipase C and cyclic AMP cascades in human thyroid
E Laurent, J Mockel, J Van Sande, I Graff… - Molecular and cellular …, 1987 - Elsevier
E Laurent, J Mockel, J Van Sande, I Graff, JE Dumont
Molecular and cellular endocrinology, 1987•ElsevierIn human thyroid slices prelabeled with myo-[2-3 H] inositol, thyrotropin (TSH, 3–30 mU/ml)
stimulated IP 3, IP 2 and IP 1 generation over a prolonged time course. The cAMP response
was much more sensitive to TSH, peaking between 1 and 5 mU/ml. Forskolin (10− 5 M) and
isoproterenol had no effect on basal IP levels, while carbamylcholine (10− 5 M, 10− 4 M)
also increased IP accumulation. These data suggest that in the human thyroid, TSH
activates a phospholipase C generating IP 3 and diacylglycerol independently of the well …
stimulated IP 3, IP 2 and IP 1 generation over a prolonged time course. The cAMP response
was much more sensitive to TSH, peaking between 1 and 5 mU/ml. Forskolin (10− 5 M) and
isoproterenol had no effect on basal IP levels, while carbamylcholine (10− 5 M, 10− 4 M)
also increased IP accumulation. These data suggest that in the human thyroid, TSH
activates a phospholipase C generating IP 3 and diacylglycerol independently of the well …
Abstract
In human thyroid slices prelabeled with myo-[2-3H]inositol, thyrotropin (TSH, 3–30 mU/ml) stimulated IP3, IP2 and IP1 generation over a prolonged time course. The cAMP response was much more sensitive to TSH, peaking between 1 and 5 mU/ml. Forskolin (10−5 M) and isoproterenol had no effect on basal IP levels, while carbamylcholine (10−5 M, 10−4 M) also increased IP accumulation. These data suggest that in the human thyroid, TSH activates a phospholipase C generating IP3 and diacylglycerol independently of the well-known adenylate cyclase stimulation. They validate in the human model a dual mode of action of the hormone previously proposed on the basis of indirect observations.
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