A few further experiments with pituria / by Sydney Ringer and William Murrell.

  • Sydney Ringer
Date:
[1879]
Catalogue details

Licence: Public Domain Mark

Credit: A few further experiments with pituria / by Sydney Ringer and William Murrell. 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.

    4/4 page 134
    Exp. 5. We applied a little of a 10 p. c. solution of nitrate of pilo- carpine to a heart beating at 40 per minute. The heaii, stopped almost immediately in wide diastole. After two minutes of complete arrest a little pituria was applied about every half minute. During the next eight minutes the heart gave a strong contraction, and after eight minutes it suddenly commenced beating strongly at 30 per minute, and so continued during the time we watched it, that is the next ten minutes. Antagonism between pituria and pilocarpine on the frog's lieart. Date. Decrease after application of pilocarpine. Loss of strength after application of pilocarpLae. Increased frequency after appli- cation of pituria. Increased strength after application of pitiuna. Contractions continued more than Jan. 1 » 1 » 1 » 2 » 2 Heart stopped 16 beats 16 beats 16 beats Heart stopped Heart stopped extremely feeble )) Heart stopped 40 beats 12 beats 12 beats 4 beats 30 beats became strong >) » seven hours seven hours four houra We see then that pituria will quicken and greatly strengthen a heart slowed and much weakened by pilocarpine, and even restore the contractions to a heart arrested by pilocarpine. In respect therefore to its antagonism to muscarin and pilocarpine, the solanaceous plant pituri acts like the alkaloids from other solanaceous plants, for instance atropia and duboisia. As pituria, like atropia, antagonizes the action of muscarin and pilo- carpine on the frog's heart, we were anxious to know if pituria, like atropia, paralyses the inhibitory apparatus of the heart. Mr Waters, of the Physiological Laboratory at Cambridge, kindly performed this experiment for us, and finds that pituria has by itself no direct effect on the number or force of the heart's contractions, but so affects the vagi that electric stimulation of them no longer slows or arrests the heart but increases the frequency of the beats. Pituri therefore is more closely allied to tobacco, as Baron Muller has suggested, than to any other solanaceous plant, for tobacco contracts the pupil, topically aj^lied to the eye or when administered by the stomach. It also causes salivation and perspiration, great weakness, and sometimes violent muscular tremblings.
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