The Pharmacology of Inflammation. I. Technic.

Abstract

In the induction of inflammatory reactions, two desiderata should be satisfied: (1) The reaction produced must be readable and fairly quantitative. (2) It should be repeatable a number of times in the same animal. For this purpose the conjunctival mucus membrane of the rabbit offers a sensitive surface well supplied with nerves and blood vessels; easily observed without undue disturbance to the animal, and anatomically constructed into a pouch capable of holding drugs for a relatively long time. The experiments of Am-berg, Loevenhart, and McClure, 1 and Chiari and Januschke 2 show conclusively that pure mustard oil so injures the conjunctival mucus membrane and the cornea that only one experiment can be performed on any individual animal. It is obvious that a technic which would not produce a permanent damage to the structure of the eye would permit a more reliable study of the effects of drugs on the inflammatory process.

In the experiments here reported, the objections to the use of pure mustard oil as the irritant were obviated by substitution of a 15% solution of essential oil of mustard in mineral oil. One drop of the latter instilled into the conjunctival sac of a rabbit produced a reaction which was readable, and from which the animal recovered completely in from 7 to 14 days, at which time the experiment could be repeated. Some of the animals were used for as many as 14 experiments, without permanent injury to the eye. In 114 instillations made in 27 rabbits, the following phenomena were constantly observed: (a) blepharospasm which lasted about an hour; (b) lachrymation for about 15 minutes; (c) immediate injection of the conjunctival blood vessels, which reached a maximum in 15 minutes, but was still present after 48 hours; (d) pin-point miosis, the pupil attaining the size of the control pupil in about one hour; (the miosis was unaffected by atropine); (e) edema of the conjunctival mucus membrane, which constituted the most constant and readable phenomenon of the inflammatory reaction.