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[Histological study of the paracervical ganglion (Frankenhäuser) in mice (author's transl)].

The paracervical ganglion in dd-mice ranging in age from birth to 90 days was studied qualitatively and quantitatively by light microscopy. The paracervical ganglion is located just lateral to the fornix vaginae, and is shaped like a flattened cone. Out of the parenchymal cells, nerve cells are 97% and chromaffin cells are 3%, respectively. The chromaffin cells are arranged in small clusters or individually, and are scattered throughout the ganglion. Their chromaffin reaction varies in density from cell to cell. In neonatal mice, the ganglion consists of nerve cells and small spherical cells. With advancing age, as the small cells decrease in number, chromaffin cells appear. At 20 days of age, the ganglion is almost similar in structure to that of the adult. The nuclear and cellular size distribution curves of nerve cells are symmetrical in pattern after the age of 20 days. The nuclear size distribution curves of the chromaffin cells are symmetrical and are almost the same in pattern in newborns as in adults. The cellular size distribution curve of chromaffin cells are symmetrical before 20 days of age, but, with advancing age, the curve shifts to the larger size and becomes asymmetrical in pattern due to an increase of larger cells.

Age Factors↗

The ultrastructure of paraganglia associated with the inferior mesenteric ganglia in the guinea-pig.

The paraganglia of the inferior mesenteric ganglia in the guinea-pig are composed of small chromaffin cells containing an abundance of granule-containing vesicles. The chromaffin cells are almost completely surrounded by satellite cells. In areas in which satellite cell processes do not intervene, the membranes of adjacent chromaffin cells are closely apposed and often form specialized attachment zones. The paraganglia contain a dense capillary network, the endothelial cells of which are often extremely attenuated and show areas of fenestration. The processes of chromaffin cells approach close to the capillary walls and are often bare of satellite cells covering on the side facing the capillary. Evidence has been obtained for the exocytotic release of the contents of chromaffin cell vesicles into pericapillary spaces. Synapses of cholinergic and noradrenergic axons are seen on the chromaffin cells. The cholinergic axons degenerate when the praganglia are decentralized, but the noradrenergic axons, which appear to arise from the local inferior mesenteric ganglia, remain intact. The results suggest that the paraganglia have an endocrine function.

Animals↗

Differential and coordinate regulation of TH and PNMT mRNAs in chromaffin cell cultures by second messenger system activation and steroid treatment.

Primary cultures of chromaffin cells were prepared from bovine adrenal medullae and the levels of mRNA for tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) determined. The cells expressed moderate levels of TH mRNA and low levels of PNMT mRNA. The latter appeared to be more sensitive than TH mRNA to variations in the culture medium. The treatment of cultures with agents that activate signal transduction pathways, forskolin or phorbol esters, dramatically enhanced the expression of both mRNAs. The forskolin-induced increases in the steady-state levels of TH and PNMT mRNAs occurred rapidly and were apparent within 5 hours. These data suggest that the TH and PNMT genes can be regulated by second messengers. In contrast, dexamethasone treatment dramatically increased PNMT mRNA with no change in TH mRNA. The increase in PNMT mRNA was apparent within 6 hours of addition of the drug to the culture medium.

1-Methyl-3-isobutylxanthine↗