Fluorescence Histochemical Findings of the Stomach Walls in Response to Ulcerogenic Stimuli in Rats

Abstract

Depending upon the origin of the stimuli which signal the secretion of gastric juice, three distinct aspects of secretion have been elucidated: the cephalic, gastric and intestinal. The efferent cholinergic mechanism is involved in the cephalic phase of gastic secretion, because cutting of the vagi just above the stomach completely eliminates the secretion.On the other hand, participation of gastrin to the gastric phase of secretion and its chemical structure have recently been demonstrated (1). However, the gastric secretion mechanism is more complicated. It is possible that the intact cholinergic innervation (2) and the presence of endogenous monoamines in the gastric wall (3) are the prerequisite to the gast rin-induced gastric secretion.There are controversial reports regarding the effect of adrenergic stimuli on the gastric secretion (4-7). In the mucous membrane of the glandular portion of the rat stomach, dopa-decarboxylase activity is high (8), but the high activity is not explained by the number of mast cells (9) and adrenergic nerves (10, 11) in the gastric mucosa. The distribution of the enterochromaffin cells is also different from that of gastric dopa decarboxylase (8). Intraperitoneal injection of dopa or 5-hydroxytryptophan (5-HTP) to rats causes a marked increase in the concentration of dopamine and 5-hydroxytryptamine (5-HT) in the gastric mucosa, and the amines are located to an enterochromaffin-like cell system in the pyloric part of the gastric mucosa (8). However, the physiological significance of the uptake and decarboxylation of dopa or 5-HT remains to be settled.In the present experiments the distribution of the endogenous monoamines in the structures of the gastric wall of the rat was studied using a formaldehyde fluorescence tech nique (12, 13). The temporal changes of the monoamine fluorescence were also followed in the course of formation of the gastric ulcers in the Shay rat and the restraint, cold exposed rat. METHODSMale and female \Vistar rats weighing 150 to 200 g were used.They were housed in an individual cage at the room temperature of 22± 1 C at least for one week prior to

Vagal regulation of insulin, glucagon, and somatostatin secretion in vitro in the rat.

“…Holst et al (23) Under such condition, the electrical vagal stimulation attained a peak insulin value within 2 min, followed by a rapid fall, despite the persistence of stimulation. Such a secretory pattern has been commonly recognized in previous in vivo experiments (7,10 Since previous studies have demonstrated that the vagus nerves contain adrenergic fibers (14,15), it might be possible that adrenergic fibers in the vagus nerve contribute to insulin and glucagon secretion induced by vagal stimulation. In the present study, we then studied the effect of adrenergic blocking agents.…”

“…Using this procedure, we have investigated the effects of vagal stimulation on insulin, glucagon, and somatostatin secretion. Furthermore, since vagus nerves is shown to contain not only cholinergic fibers but also adrenergic fibers (14,15), we have studied the effects of cholinergic and adrenergic blockers on insulin, glucagon, and somatostatin responses to vagal stimulation.…”

Fluorescence Histochemical Demonstration of Adrenergic Nerve Fibers in the Vagus Nerve of Cats and Dogs

“…They were mainly unmyelinated and of small diameter. The inten sity of the fluorescence was much less than that of the adrenergic fibers innervating the salivary glands (11, 14, 16,), heart (17) and stomach (18). The absence of the specific fluorescence from many of the myelinated fibers of the vagus nerve indicates that the preg anglionic fibers of the vagus nerve contain few if any adrenergic component.…”

Fluorometric Assay of Tissue Histamine

“…Thus, the omission of washing the butanol phase with salt saturated NaOH and the use of phosphorylated cellulose column increased recoveries of tissue histamine with separation from histidine or spermidine, enough to be applicable to pharmacological studies. The ulceration of stomach of cold-stressed restraint rat was prominent in the portion of body, while that of pylorus-ligated Shay rat was in the portion of rumen (10). The relationship between the ulcer formation and histamine level of stom ach will be considered in a future report, in conjunction with the level of serotonin.…”

“…The content of histamine in the body was more than twice as much as that of rumen or antrum. Pylorus-ligated Shay rats and cold exposed restraint rats were prepared as described (10) , and histamine was assayed. With the progress of ulceration the content of histamine, particularly in the body of cold-exposed Histamine is transferred to n-butanol, returned to an aqueous phase, applied to Cellex-P column (0.6 x 2 cm).…”