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Biomedical subjects

H Thoenen

Publications and source records attributed to H Thoenen.

At least 289 records · Page 16Linked to original sources
PubMed1971

Selective induction by nerve growth factor of tyrosine hydroxylase and dopamine- -hydroxylase in the rat superior cervical ganglia.

Treatment of newborn rats with 10 mug/g of nerve growth factor for 10 days enhanced not only the growth but also the differentiation of neuroblasts in superior cervical ganglia. These morphological changes were accompanied by selective induction of tyrosine hydroxylase and dopamine beta-hydroxylase (EC 1.14.2.1), whereas the total and specific activities of other enzymes involved in biosynthesis or metabolic degradation of norepinephrine rose only in proportion to the increase in volume of the sympathetic ganglia. There are remarkable similarities between this effect of nerve growth factor and the induction of trans-synaptic enzymes by increased activity of the sympathetic nervous system.

Animals↗
PubMed1970

Phase difference in the induction of tyrosine hydroxylase in cell body and nerve terminals of sympathetic neurones.

The induction of tyrosine hydroxylase in the nerve terminals of the rat heart by reserpine lags behind that in the stellate ganglion by two to three days. Cycloheximide given three days after reserpine blocks the further rise of the enzyme in the nerve terminals. The increase in tyrosine hydroxylase activity of the lumbar ganglion is as marked as that in the stellate ganglion. The increase of enzyme activity in the sciatic nerve after reserpine administration resembles that found in the heart nerve terminals. Determination of enzyme activity in segments of sciatic nerves indicates a two-day lag and then a proximal-distal transport of enzyme, but the apparent rate is not sufficient to account for the increase in enzyme in the nerve terminals. These findings are compatible with the local synthesis of induced tyrosine hydroxylase in the nerve terminals rather than the peripheral movement of the completed enzyme.

Animals↗