Part 14

Maisch, J. M. Poisonous Species of Astragalus. Amer. Journ. Pharm., vol. 51, p. 240. 1879.--Fleurot. Chimiques et Pharmaceutiques sur la Racines d'Astragale sans Tiges. Journ. de Chim. Med., vol. 10, p. 656. 1834.

Porcher, F. P. Resources of the Southern Fields and Forests, p. 204. 1869.

Smith, J. G. Fodder and Forage Plants. U. S. Dept. Agric., Div. Agrost., Bul. 2 (rev. ed.), p. 12. 1900.

Holmes, E. M. Notes on Chinese Drugs. Pharm. Journ. and Trans., vol. 21, 3 s., p. 1149. 1891.

Hough, W. Environmental Interrelations in Arizona. Amer. Anthropologist, vol. 11, pp. 143, 147. 1898.

Barrows, D. P. Ethno-Botany of the Coahuilla Indians of Southern California, p. 67. 1900.

Matthews, W. Navajo Names for Plants. Amer. Nat., vol. 20, p. 772. 1886.

Givens, A. J. Loco or Crazy Weed. Med. Century, vol. 1. p. 21. 1893.--Compare Hurd, H. M. Amer. Journ. Insanity, vol. 42, p. 178. 1885-86.

Rosenthal, D. A. Synopsis Plantarum Diaphoricarum, Erlangen, 1861, p. 1004. Greshoff, M. Beschrijving d. Giftige en Bedwelmeude Planten bij de Vischvangst in Gebrulk, p. 51. 1900.

Pott, E. Handb. d. tierisch. Ernährung, vol. 2, p. 113. 1907.

=LABORATORY EXPERIMENTS--PHYSIOLOGICAL.=

The first point in our investigations was to determine whether the plant exerted any poisonous action and to find some animal which responded regularly to it; then to ascertain if the lack of results of previous investigators was not due to insufficient doses, and later to see if by feeding smaller amounts at repeated intervals symptoms comparable to those described as occurring on the range could not be produced. The animal finally selected was the rabbit.

=EXPERIMENTS ON RABBITS.=

=ACUTE CASES.=

Experiment No. 1.--On September 8, 1905, an aqueous extract of 333 grams of fresh Astragalus mollissimus, made in Hugo, Colo., and shipped preserved in chloroform, killed a rabbit weighing 1,616 grams in one hour and thirty-five minutes, while an extract corresponding to 167 grams merely caused drowsiness and loss of appetite in a rabbit weighing 765 grams.

Experiment No. 2.--On November 29, 1905, a rabbit weighing 1,162.3 grams was fed with a concentrated aqueous extract of 500 grams of fresh Astragalus mollissimus, which had been shipped from Hugo, Colo., preserved in chloroform in sealed vessels. This animal died in one hour and ten minutes. The symptoms consisted in dullness, rapid respiration, and signs of pain. At autopsy the stomach and upper part of the small intestines showed hemorrhagic ecchymoses, with dilation of the dural vessels of the brain and cord, with a clot over a portion of the spinal cord.

Experiment No. 3.--On February 13, 1906, a rabbit weighing 992 grams was fed with a concentrated aqueous extract of 500 grams of the fresh Astragalus mollissimus, collected in September and preserved in chloroform water. Before feeding, the rabbit's ears were warm and the rabbit struggled when any attempt was made to turn him on his back. The temperature at 10.50 a.m., the time of feeding, was 103.5°F.; at 11.15 a.m., 102.5°F. At 11.30 a.m. the rabbit was breathing very rapidly and would stay on his back for some time if placed so. The temperature at this time was 102.6°F. Both pupils, the one exposed to the light and the one protected, were contracted. At 12.02 p.m. convulsive movements of the legs appeared. The rabbit made one leap, the temperature rose to 103.6°F., and after a few convulsive movements of the limbs the anus relaxed and a small stool appeared, the pupils dilated, and the animal died at 12.06 p.m.

Experiment No. 4.--The feeding of the extract of 464 grams induced a fall in temperature of 2.4°F. in three hours, and the rabbit died several hours later (at night).

Experiment No. 5.--March 2, 1906, a rabbit weighing 928 grams was fed with a concentrated extract of 500 grams of the fresh seeds and pods of Astragalus mollissimus, made in September, 1905, and preserved with chloroform water. This animal died in one hour and seven minutes. The animal showed the usual post-mortem conditions.

It was thus found that the aqueous extract of 500 grams of the fresh Astragalus mollissimus would cause death in about one hour in rabbits weighing about 2 pounds (907 grams), these rabbits showing constant clinical symptoms--urination, paralysis, more or less convulsive muscular twitchings, often terminating in general convulsions, drowsiness, and stupor, with more or less anesthesia. The pupils at the time of death were often unequal. At first there was usually a slight rise in temperature, but this was soon succeeded by a fall. Often there were soft stools. The post-mortem lesions in these cases were marked congestion, with hemorrhages in the stomach walls and a secretion of thick mucus. The portions of the stomach walls most affected were the dependent portions near the cardiac end. The intestines showed dilatation of the blood vessels. The mesenteric vessels and also the vessels in the cerebral portions of the dura were markedly dilated; in some cases there were clots, especially at the posterior portion of the brain, between the cerebrum and the cerebellum. At times there were clots over the dorsal portion of the cord. On cutting into the brain the brain substance itself did not appear to be congested. The cord seemed about normal, but the vessels of its membranes were well marked. The other organs showed nothing characteristic macroscopically. These experiments were repeated many times and found to be constant.

These acute symptoms were likewise produced by an extract of 500 grams of the fresh Aragallus lamberti from Arizona preserved in chloroform water (rabbit weighing 1,998 grams). An aqueous extract of 150 grams of the dried Astragalus mollissimus from Imperial, Nebr. (1906), caused death in one hour and fifty-eight minutes in a rabbit weighing 1,530 grams, and an extract of 100 grams killed in one hour and twenty-two minutes a rabbit weighing 736 grams.

An aqueous extract of 100 grams of the dried Astragalus bigelowii induced death in one hour and thirty-eight minutes, the rabbit weighing 1,502 grams.

An aqueous extract of 150 grams of Astragalus nitidus collected at Woodland Park, Colo., in 1906 induced death in three hours and five minutes, the rabbit weighing 1,672 grams.

An aqueous extract of 200 grams of the dried Astragalus bisulcatus caused death after several hours (at night), the rabbit weighing 2,423 grams.

In certain cases this production of acute symptoms was not entirely a question of salt action, as was shown by certain other experiments. In other cases salt action seems to be the important factor, so that the production of these acute symptoms can not always be considered characteristic.

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FOOTNOTES:

In all cases in which the plants were preserved with chloroform sealed vessels were used for shipping. The chloroform was carefully evaporated off in vacuo before feeding the extract, the evaporation requiring several hours. The plants were collected by Dr. C. Dwight Marsh, in charge of the field investigations at Hugo, Colo.