Central origin of canine vidian nerve studied by the HRP method

Central origin of the vidian nerve in the dog was investigated using the retrograde tracing technique of horseradish peroxidase (HRP). After HRP was applied to the vidian nerve, labelled neurons were found in the medulla oblongata and the geniculate ganglion but could not be found in the trigeminal ganglion. Labelled neurons in the medulla oblongata were found not only in the dorsal part but also in the ventral part to the facial motor nucleus and were maximum in number at the level of the rostral third of the facial motor nucleus. These labelled neurons were generally medium-sized multipolar neurons with well-developed dendrites.

Ultrastructure and chloride cytochemistry of the hindgut epithelium in the larvae of the seawater mosquito, Aëdes togoi Theobald

The hindgut of Aëdes togoi larvae adapted to various external salinities was studied by light and electron microscopy. The larvae's pyloric chamber and the ileum of the hindgut are surrounded by a thick muscular layer and lined with a very thin unspecialized epithelium. There is no detectable difference in the ultrastructural organization of the epithelium between seawater-adapted and freshwater-adapted larvae. The rectum and the anal canal are greatly dilated and densely tracheated and have a very thick, highly specialized epithelium. The rectal epithelium is characterized by shorter apical and longer basal infoldings closely associated with mitochondria, and a particulate coating on the apical infoldings. The intercellular spaces and the basal channels are tightly closed in the rectal epithelium of freshwater-adapted larvae, whereas widely dilated in that of 100 to 200% seawater-adapted larvae. The rectum seems to reabsorb water from excretory fluid when larvae are in hyperosmotic media. The anal canal epithelium possesses well-developed apical infoldings, which are coated with small particles an intimately associated with mitochondria. The basal infoldings are short. No perceptible difference in the ultrastructural organization of the epithelium was observed between seawater-adapted and freshwater-adapted larvae. The lumina of the apical infoldings of the anal canal epithelium in seawater-adapted larvae, however, demonstrated a strongly positive reaction to the cytochemical assay for chloride ions, whereas the reaction was very weak in freshwater-adapted larvae. Unlike salt-water-mosquito larvae of the other species, in which the rectum is considered to be concerned with the formation of hyperosmotic urine, the anal canal in A. togoi larvae seems to play an important role in excretion of excess ions in the haemolymph when adapted to hyperosmotic media.

Histochemical demonstration of peripheral autonomic innervation in canine nasal mucosa by retrograde axonal transport of horseradish perioxidase

The peripheral autonomic nervous pathways of the nasal mucosa in dogs were investigated by the horseradish peroxidase (HRP) method. HRP was applied to the nasal mucosa, caudal nasal nerve, ethmoidal nerve, vidian nerve and pterygopalatine ganglion in 20 dogs, and retrogradely labelled neurons were observed in the superior cervical ganglion (SCG) and the pterygopalatine ganglion (PPG) by the blue reaction method. It was suggested that the vidian nerve, the maxillary branch of the trigeminal nerve, the caudal nasal nerve, the pterygopalatine nerve and the ethmoidal nerve contained the postganglionic sympathetic fibres which originated in SCG and terminated in the nasal mucosa. Moreover, other sympathetic pathways, such as those around the blood vessels, were also suggested to be a main route. It was suggested that the postganglionic parasympathetic fibers originating in PPG travelled along the caudal nasal nerve and the ethmoidal nerve.

Studies on the intracellular cAMP metabolism of tonsillar lymphocytes

cAMP metabolism, including the intracellular cAMP level and adenylcyclase activity, was studied in tonsillar and peripheral lymphocytes. The basal activity of adenylcyclase was significantly higher in tonsillar lymphocytes than in peripheral lymphocytes, although the basal level of intracellular cAMP did not differ. The responsiveness of the intracellular cAMP level and adenylcyclase activity stimulated by 10(-5) M isoproterenol, or 10(-5) M prostaglandin E1, which was thought to stimulate this enzyme through a specific receptor, was significantly lower in tonsillar lymphocytes than in peripheral lymphocytes. Moreover, the responsiveness of adenylcyclase activity to 10(-2) M NaF, which was thought to stimulate this enzyme directly, was also significantly lower in tonsillar lymphocytes. Tonsillar T lymphocytes represented a lower cAMP basal level than tonsillar B lymphocytes, but no difference was observed in the responsiveness of intracellular cAMP to the above agents. Tonsillar lymphocytes derived from patients with recurrent tonsillitis represented significantly lower cAMP responsiveness than those from patients of other chronic tonsillitis. Furthermore, in the tonsillar lymphocytes from patients with a recent attack of acute tonsillitis, a more depressed responsiveness of the intracellular cAMP level to the above agents was recognized. The cAMP basal level was not changed by these pathological alterations of tonsillitis.

cAMP and cGMP in the human parotid saliva

Human parotid saliva was revealed to contain considerable amounts of cAMP and cGMP. On sour lemon drop stimulation, the salivary cyclic nucleotides concentration decreased and the cyclic nucleotides secretory rate increased in close relationship with the salivary flow rate in control subjects. On feeding, both cAMP concentration and secretory rate increased significantly in control subjects. Parotid saliva from a patient of Sjögren's syndrom was revealed to have a significantly higher of cGMP concentration than those from control subjects. Saliva derived from the malignant tumor of the parotid gland was revealed to have a higher cGMP concentration and a lower cAMP concentration than the healthy site. From these findings, the possibilities of the clinical usefulness of studying salivary cyclic nucleotides were discussed.

Metabolism of cyclic nucleotides in allergic rhinitis: studies on lymphocytes, granulocytes, and plasma level

The effect of isoproterenol on the cyclic nucleotide level in peripheral lymphocytes and granulocytes with allergic rhinitis patients and normal subjects has been studied. Responsiveness to 10(-5) M isoproterenol of lymphocytes decreased in the case of allergic rhinitis patients. When asthma was complicated to perennial rhinitis, a more significant depression was noted. In granulocytes the same tendency as with lymphocytes was noted although the difference was not significant. Basal level and responsiveness to 5 X 10(-3) M theophylline of both lymphocytes and granulocytes were similar in allergic rhinitis patients to normal subjects. The ratio of plasma cAMP to cGMP concentration was lower in the allergic rhinitis patients although the difference was not significant.

Cyclic nucleotide levels of nasal secretions in allergic patients and control subjects

Cyclic nucleotides (CND) levels of nasal secretions were studied in allergic rhinitis patients and control subjects. In methacholine-induced nasal secretion, allergic rhinitis patients had lower cAMP levels, higher cGMP levels and a lower cAMP/cGMP ratio than the control subjects. A close relationship was found between CND levels and the severity of daily symptoms in both methacholine-induced and antigen-induced nasal secretions.