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The chronic experiments on dogs with fundal fistulas have revealed that the partial stomach denervation (selective proximal, selective distal and subcardial vagotomies) decreases the gastric secretory responses caused by submaximal and maximal doses of histamine. Selective and extragastral vagotomies do not change the histamine gastric secretion in dogs, stimulated by the maximal histamine dose.

The preganglionic parasympathetic innervation of normal and vagotomized rat stomach have been investigated by the horseradish peroxidase (HRP) technique. After the HRP injection into the antrum and fundus muscles the labelled cells were revealed in nuclei dorsalis nervi vagi bilaterally, but preferentially in the left nucleus. The most numerous labelled cells were observed after injection into the region of the curvatura minor. When HRP was injected into the vagotomized stomach one, three, four and six months after the surgery procedures the labelled cells in the nuclei nervi vagi were not revealed. Mechanisms of regeneration of nervi vagi efferents and normalization of the stomach activity are discussed.

In chronic experiments on dogs with the gastric fistulas it was shown that H1-histamine blockers (suprastin, peritol, pipolphen) fail to enhance histamine secretion and a selective H1-agonist IEM-813 fails to suppress it. It was also found that the ability of pipolphen to suppress the gastric secretion was due to its cholinolytic properties.

In chronic experiment on dogs it has been established that the subcutaneous injection of equimolar doses of izadrine (nonselective beta-adrenergic agonist), alupent (moderately selective beta 2-adrenergic agonist) and salbutamol (predominantly beta 2-adrenergic agonist) suppresses the pentagastric secretion approximately in the same degree. The blockade of beta-adrenoreceptors by the anapriline intensifies the gastric secretion stimulated by pentagastrin. All investigated adrenoactive agents didn't effect the dogs' histamine gastric secretion. In healthy men the activation of beta 2-adrenergic receptors by alupent accompanied by the expressed intensification of basal, pentagastrin and submaximal histamine gastric secretion. The blockade of these receptors by anaprilin decreases the gastric secretion. It has been concluded that only beta 2-adrenoceptors take part in the gastric secretion regulation. Considerable specific differences in the reaction of gastric glands on the activation of beta-adrenoreceptors are revealed: in human beings it leads to the excitation, in dogs--to the suppression of secretory cells.

Peritol produces a marked inhibiting effect on the gastric secretory function in dogs with fistulas of the stomach and duodenum stimulated by insulin and carbacholin while the influence on the pentagastrin gastric secretion was weaker. In its effect on the histamine secretion peritol inhibits only the secreted juice pepsin. The practical importance of the above for clinical gastroenterology is suggested.

Selective proximal vagotomy (SPV) evoked the same alterations in the motility of fundal part of the dog stomach as truncal vagotomy. Within 2-3 months the fundal motility was completely normalized. If the SPV were carried out with preserved innervation in the cardial zone, the motility restoration was accelerated to 7-10 days. But is SPV was added to the disconnection of antral part with proximal stomach, its motility did not restore at all. SPV initially suppressed the insulin secretion to 70-85 per cent; in 6-12 months this suppression decreased to 60 per cent and stabilized on this level. The Auerbach plexus seems to differ from the Meissner plexus in that the former can transfer the gaval influence from the innervated zone into the denervated one. Judging by the functional indices the growth of vagal fibers from the innervated zone into the denervated one did not take place.

Subcutaneous injection of serotonin (0.3 mg/kg) inhibited the carbocholine gastric secretion in dogs. The insulin secretion was suppressed only by the i.v. injection of serotonin. The latter decreased the blood flow in the stomach mucosa and intensified the motility of gastro-intestinal tract in hungry and replete dogs. The vagotomy and benzohexonium weakened the inhibitory serotonin effect on the secretion induced with peripheral stimuli. The effect of serotonin on the gastric secretion in the conditions of natural digestive process in discussed.

In dogs with fistulas in fundal and antral parts of the stomach and in the proximal part of jejunum, subcutaneous and i.v. administration of pentagastrin and i.v. administration of cholecystokinin caused reciprocal reactions in the stomach: pentagastrin suppressed the motility of fundal part and activated the contractions of antral part, whereas cholecystokinin activated the contractions of fundal part and suppressed the motility of antral part of the stomach. Excepting a more complex character of pentagastrin and cholecystokinin effects on the jejunum contractions, the responses were reciprocal as well. Pentagastrin exerts mainly a suppressing effect whereas cholecystokinin--an activating one. Possible biological significance of the hormones interactions while maintaining evacuatory function of the stomach, is discussed.

The influence of vagotomy on histamine gastric secretion and the ability of the H2-blocker cimetidine to suppress histamine gastric secretion was examined in humans and dogs. It was established that vagotomy in humans decreased histamine acid secretion. The relative ability of cimetidine to suppress gastric secretion remained unchanged. In dogs, vagotomy increased acid rather than pepsin secretion stimulated by histamine. The inhibitory effect of cimetidine on acid secretion was more profound in dogs with an intact vagus nerve. It is suggested that vagotomy in dogs but not in humans increased endogenous histamine secretion which intensified the stimulatory effect of endogenous histamine and led to the potentiation of the inhibitory action of cimetidine on histamine acid secretion.