The effect of noradrenaline on the gastric secretory response to histamine in the dog

Abstract

The discovery by Emmelin & Muren (1951) that parasympathetic denervation of the salivary glands sensitizes them to circulating adrenaline suggests that a similar phenomenon might be demonstrable elsewhere in the alimentary tract, notably in regard to the gastric glands. The experiments to be reported here were' undertaken as a preliminary study of the effect of noradrenaline on gastric secretion stimulated by histamine before investigating the influence of vagotomy. The confusion which formerly existed regarding the effects on gastric secretion of adrenaline or sympathetic stimulation (Babkin, 1950;Code, 1951) has been partly clarified by the work of Code & Forrest (1954), who found that in conscious dogs provided with Heidenhain pouches, infusion of adrenaline or noradrenaline inhibited a secretion of gastric acid evoked by histamine. The results of the experiments to be described, and the interpretation of them, are in certain respects different from those of Code & Forrest. METHODSAt a preliminary aseptic operation a metal cannula was installed in the most dependent part of the stomach in each of five dogs. In three of the animals, permanently indwelling polythene cannulae were inserted into the external jugular vein by a simplification of the method of Stroud, Stetson & Rahn (1952). All the animals remained in good health throughout the investigation.A constant-rate injection apparatus was used for intravenous infusion of histamine and noradrenaline solutions. This consisted of three 20 ml. syringes which were emptied simultaneously at the same rate (approx. 3-6 ml./hr) by a common motor drive. A three-way tap was fitted to each syringe so that the contents of any or all of them could be discharged into the dog at the same time. The syringes contained respectively (1) 0-9% NaCl solution, (2) histamine acid phosphate in 0 9% NaCl solution, and (3) noradrenaline acid tartrate in 0-9% NaCl solution. The histamine solution was infused continuously, together with either of the other two solutions. The noradrenaline solution was turned on at the same time as the saline was diverted into a reservoir, and vice versa, so that the inflow of histamine was unaffected. The solutions from the syringes passed to the dog via a length of fine-bore plastic tubing which either connected with the jugular cannula (see above), or in some experiments was introduced directly into a leg vein through a

The Effects of Infusions of Adrenaline and Noradrenaline on the Heart Rate and Arterial Blood Pressure of Conscious Dogs

“…The experiments of Pickford and Watt were conducted with the animals standing and not lying as in our experiments, and the doses of adrenaline were larger than those we have used. Harries [1956] found complex changes in heart rate, usually slowing, from the infusion of noradrenaline (0.3-1 2 itg./kg./min.) in conscious dogs already receiving histamine (0-15-1.5 lg./kg./min.).…”

THE ROLE OF β1 ‐ AND β2‐ADRENOCEPTORS IN THE INHIBITION OF GASTRIC ACID SECRETION IN THE DOG

“…The parasympathetic nervous system is undoubtedly involved in eliciting and facilitating gastric secretion but there is disagreement about the role and importance of the sympathetic nervous system (Harries, 1956;Sanders, 1976). Although it is well established that noradrenaline can inhibit gastric secretion, this is usually attributed to a reduction in the gastric mucosal blood supply, resulting from activation of a-adrenoceptors (Curwain & Holton, 1972).…”

A study of gastric secretion and blood flow in the anaesthetized dog

“…None of the previous workers has measured these effects simultaneously, but Forrest & GASTRIC SECRETION AND BLOOD FLOW Code (1954) and Harries (1956) have demonstrated the marked inhibitory effect of this amine upon histamine-induced acid secretion in the unanaesthetized dog, either in a Heidenhain pouch or from a stomach having a simple gastric fistula. Linde (1950), however, reported that noradrenaline had no effect on histamine-induced secretion from stomach pouches in cats, and Karvinen & Karvonen (1952) reported similar findings in dogs.…”