The action of some isoquinoline derivatives / by P.P. Laidlaw.

  • Laidlaw, Patrick Playfair, 1881-1940.
Date:
[1911?]
Catalogue details

Licence: In copyright

Credit: The action of some isoquinoline derivatives / by P.P. Laidlaw. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    of 6:7-dimethoxy 2-methyl 3:4-diliy(lro-iso-quinoliniutii chloride is 61-62° C. (corr.). The physical properties of the product were the same as the original product, and, moreover, the physiological action was identical; it produced a rise of hlood-pressure accompanied by some slowing of the heart heat (tig. 17), and had the characteristic effect on the isolated uterus. There can be no doubt, then, that the method of excretion of this iso-quinoline derivath-e is by the urine. The yield obtained was not very large, but it is very probable that if larger doses were given and the urine collected for a longer period after the administration that this would be greatly increased. This series of iso-quinoline derivatives is without action on intestinal movements. Isolated rabbit’s jejunum suspended in a llinger bath continues its rhythmic movements, unaltered in time, extent or tonus, when any one of this .series of alkaloids is added to the bath. Bladder. Tlie tone of the bladder is very slightly increased hy 6 : 7-dimethoxy 1-methyl 3 :4-dihydro-iso-quinolinium chloride, and this was also found to be the effect of hydrastinine. Cotarnine, on the other hand, was without effect. liesin'ratioii. As was noticed in the earlier part of this paper, 6:7-dimethoxy 2-methyl 3 :4-dihydr<)-iso-(iuinolinium chloride and hydrastinine and cotarnine have an effect on the resjjiratory centre. In large doses their depressant action on the centre is sufficient to cause cessation of respiration and death. Slowing of the respiration without signiHcant alteration in depth was noticed when doses of 20 ingm,'.. of any one of the three iso-qiiinoline derivatives was administered intravenously and the respiratory movements recorded above the blood-])ressure. Cotarnine has a slightly more marked effect than the other two. 6 : 7-dimethoxy 2-methyl 3 ; 4-dihydro-i.so-({uinolinium chloride has practically no effect on striped muscle. A nerve-mu.scle preparation soaked in 1 in l.OOt) solution of this alkaloid in llinger .solution for two hours responded quite well to electri<al stimulation of its nerve, or of the muscle direct. This concentration is considerably above that which can occur in the body. Santesson*'’ found that there was a slight diminution in sensitiveness to stimulation through the nerve when large doses of hydrastinine were given to frogs. He compares this result with those he obtained with iso-quinoline and N-methyl-iso-quinoline.-® The methylation of the nitrogen ))roducing a mild curare effect. The effect
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