Noradrenaline Content in the Heart and Spleen of the Mouse Under Normal Conditions and After Administration of Some Drugs

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In a previous paper (Muscholl & Vogt, 1964) the release of catechol amines from extramedullary chromaffin tissue had been examined, and certain differences found between the responses of extramedullary chromaffin cells perfused with Locke solution and the well-known reactions of the adrenal medulla in situ. Thus electrical stimulation of preganglionic fibres to the ganglion containing the chromaffin tissue did not cause a release of adrenaline or noradrenaline, as does stimulation of the nerve supply to the adrenal medulla. Furthermore, injection into the perfusion fluid of bradykinin or angiotensin had little or no stimulant action on extramedullary, but was known to have powerful action on medullary chromaffin tissue.The present work was undertaken in order to find out whether these differences were due to the one tissue having been studied while the circulation was intact and the other while perfused with Locke solution, or whether the differences were inherent in the nature of the two tissues. The effect was therefore examined of stimulation of the splanchnic nerves and of the injection of a series of drugs including angiotensin and bradykinin on release of adrenaline and noradrenaline by the dog Locke-perfused isolated adrenal gland. METHODSConditions for the perfused adrenal medulla were made as similar as possible to those used for the perfusion of the extramedullary chromaffin tissue (Muscholl & Vogt, 1964). Puppies (bodyweight 2.2 to 7.5 kg) were used as donors as before, and the composition and temperature of the Locke solution, perfusion apparatus, pressure head, and gassing mixture were the same. The dissection was that used for perfusion of dog adrenals with blood (Vogt, 1951), but the adrenal gland, attached to a segment of aorta and a length of vena cava, both of which had been completely separated from the rest of the body, was cut out and placed on a small platform sunk into a polyethylene funnel from which the effluent fluid escaping from the opened vena cava was collected. Perfusion was through the superior mesenteric artery, and was started while the adrenal gland was still in situ, just as described previously for the tissue supplied by the inferior mesenteric artery. The flow through the adrenal gland was faster than through the extramedullary chromaffin tissue and ranged from 3 to 9 ml./min. Collection periods usually lasted 2 min; either the whole or one-half of such a 2-min sample was extracted, and the catechol amines were separated and assayed as in the earlier work. Recoveries of the amines averaged 70%.The following drugs were used: angiotensin (Hypertensin II aspartic-,B-amide, Ciba), bradykinin (Parke Davis), dimethylphenylpiperazinium iodide (Parke Davis), histamine bis-(dihydrogen phosphate) (B.D.H.), 2,4,5-trihydroxyphenylethylamine (6-hydroxydopamine) hydrobromide (Merck, Sharp & Dohme), methylreserpate methyl ether hydrochloride (Su 8842. Ciba), reserpine (Serpasil, Ciba) and tyramine hydrochloride.

Section: Resultsmentioning

confidence: 99%

Release of Medullary Amines From the Isolated Perfused Adrenal Gland of the Dog

Vogt

1965

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“…Noradrenaline in the first eluate was determined fluorimetrically after oxidation by ferricyanide (Euler & Lishajko, 1961; for details see Sharman, Vanov & Vogt, 1962). The catechol amines in the second eluate were estimated fluorimetrically after acetylation (Laverty & Sharman, 1964) by condensation with ethylenediamine; 4 ml.…”

Section: Methodsmentioning

confidence: 99%

Action of 2, 4, 5‐trihydroxyphenylethylamine on the Storage and Release of Noradrenaline

Laverty

Sharman

Vogt

1965

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105

Porter, have reported that a single injection of 6-hydroxydopamine (2,4,5-trihydroxyphenylethylamine) lowered the noradrenaline content of the mouse heart by more than 50% for longer than 25 days. Porter et al. (1963) proposed that this prolonged action was due to destruction of the noradrenaline binding sites by the 6-hydroxydopamine. However, since 6-hydroxydopamine is very similar to noradrenaline in its chemical properties it was possible that the 6-hydroxydopamine or some metabolite replaces the noradrenaline in the heart tissue and is then bound there, preventing the resynthesis or replacement of the lost noradrenaline.In order to investigate this question a method was devised to isolate and measure the 6-hydroxydopamine content of tissue samples, and so to see whether its persistence in the tissues could explain its action on the storage of noradrenaline. The functional state of the nervi accelerantes was tested at different time intervals after the administration of 6-hydroxydopamine, and the effect of the drug on the release of catechol amines from the adrenal medulla was examined. METHODSAdult male and female mice, young female guinea-pigs, and kittens and puppies of either sex were used in these experiments. 6-Hydroxydopamine was injected intraperitoneally or intravenously as the hydrobromide; all doses of 6-hydroxydopamine and other amines are expressed in terms of the bases.Cardiac nerve stimulation. Kittens were anaesthetized with ether followed by intravenous chloralose (80 mg/kg) and the chest was opened under artificial ventilation. In some kittens the adrenal glands were removed before opening the chest; in many, the blood pressure was measured by a mercury manometer connected to the carotid artery. The right stellate ganglion was exposed and the strand of postganglionic nerves going to the heart was placed on shielded electrodes. Rectangular pulses of 1 msec duration from a Grass SD5 stimulator were used at a frequency of 15 shocks/sec; the voltage applied was usually 20 V. The heart rate was measured from the electrocardiogram recorded on a Grass Polygraph.Perfusion of adrenal glands. Adrenal glands of puppies were perfused by gravity at 350 C with Locke solution saturated with 95% oxygen and 5% carbon dioxide. The perfusion cannula was tied into the superior mesenteric artery. The dissection was carried out as previously described (Vogt, 1951), but the isolated segments of aorta and vena cava to which the left adrenal gland was attached were excised from the body together with the adrenal gland and placed on a perforated platform resting in a funnel. The

“…Noradrenaline and adrenaline were estimated fluorimetrically as described by Sharman, Vanov & Vogt (1962), but a Locarte filter fluorimeter was used. For noradrenaline, the primary filter was an LF/2 and the secondary an Ilford No.…”

Section: Methodsmentioning

confidence: 99%

Iontophoretic Release of Adrenaline, Noradrenaline and 5‐hydroxytryptamine From Micropipets

Krnjević

Laverty

Sharman

1963

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Estimations have been made of the amounts of adrenaline, noradrenaline and 5-hydroxytryptamine released by iontophoresis from micropipettes. In most experiments, the amount released was linearly related to the total electrical charge, but the transport numbers for different pipettes, filled with samples of the same solutions of adrenaline or of noradrenaline, varied substantially. Two pipettes containing noradrenaline failed to release any appreciable amounts of the drug. The transport number of 5-hydroxytryptamine was relatively constant (mean, 0.14).