Catecholamines of endoneurial laryngeal paraganglia in the rat.

The catecholamines in the recurrent and superior laryngeal nerves of the rat were assayed by high performance liquid chromatography. The nerves were shown to contain high levels of dopamine (1.9 +/- 0.6 and 2.3 +/- 0.4 pmol, respectively) and noradrenaline (1.3 +/- 0.3 and 0.9 +/- 0.2 pmol, respectively). No adrenaline could be detected in any of the nerves. Reserpine markedly depleted the stores of these amines in both nerves. A significant increase in dopamine level was seen in the superior laryngeal nerve after treatment with a monoaminoxidase inhibitor, but not in the recurrent laryngeal nerve. The high levels of dopamine detected are presumably derived from endoneurial paraganglia which were demonstrated by glyoxylic acid-induced fluorescence. The source of noradrenaline is less evident, but noradrenaline is probably stored in both endoneurial paraganglia and in sympathetic nerve endings.

Localization of enkephalin-like immunoreactivity in the cat carotid and aortic body chemoreceptors.

The purpose of this study was to determine if enkephalin-like immunoreactivity was present in the glomus cells of the carotid and aortic body peripheral arterial chemoreceptors. Cat carotid and aortic bodies were reacted with antisera to met- and leu-enkephalin using the indirect peroxidase-antiperoxidase immunocytochemical method of Sternberger (1979). Both the carotid and aortic bodies demonstrated clusters of immunoreactive cells for both met- and leu-enkephalin. Additionally, met-enkephalin-like immunoreactivity was observed in many of the dense-core vesicles of the glomus cells of the carotid body. The glomus cells of these chemoreceptors are known to contain catecholamines which may modulate chemoreceptor activity. The presence of opioid peptide-like substances co-existing with the glomus cell catecholamines, perhaps in the same vesicles, may have important implications for a trophic influence of these peptides on glomus cell chemoreceptor modulation.

The paraganglion supracardiale vagi: an intravagal paraganglion in the rat.

In the Ham-Wistar rat, a paraganglion was found within the vagus nerve at the site of branching of the recurrent laryngeal nerve. Due to its location the name "paraganglion supracardiale vagi" is suggested. Fluorescence microscopy of the paragangkionic cells displays an intense yellow-green fluorescence indicating the presence of biogenic amines. Ultrastructurally, chief cells containing dense-core vesicles form three kinds of synaptic contacts (afferent, efferent and reciprocal) with enlarged. mitochondria-rich nerve endings.

Staining of paraganglionic cells with lead hematoxylin.

Lead hematoxylin staining in most paraganglionic cells is too faint to be observed in the light microscope (LM). Paraganglionic cells which appear stained (LM) are also known to contain more and larger specific granules (as seen in the electron microscope, EM) than those paraganglionic cells remaining unstained (LM). However, also specific granules in lead hematoxylin-negative paraganglionic cells (LM) bind lead ions (EM), which behaviour is the basis of lead hematoxylin staining. It is concluded that lead hematoxylin stains matrix material of specific granules but the amount of granule material mostly is too small to yield colour intensities to be observed in the LM.

Formaldehyde induced catecholamine fluoroscence in the mouse inferior laryngeal paraganglion.

The presence of high concentrations of catecholamines is shown in the mouse's inferior laryngeal paraganglion by means of fluorescence histochemistry. In mice, the entire organ is composed of 20 to 25 small, intensely fluorescent cells of oval shape (about 15 mum in diameter). The paraganglion is well provided with capillaries. The identification of catecholamines in the inferior laryngeal paraganglion, originally described as nonchromaffin (parasympathetic) paraganglion, presents additional evidence that all paraganglia store biogenic amines, are related to the sympathetic nervous system, and belong to the APUD cell series.