STIMULATES AND CONTRACTS MUSCULAR FIBRE 621 



Cornutine causes spastic rigidity in frogs, lasting many 

 days, even when given in very minute doses (^ of a milli- 

 gramme). In warm-blooded animals half a milligramme 

 causes salivation, vomiting, diarrhoea, and active movements 

 of the uterus, which are clonic and not tonic. The vessels 

 are contracted and blood-pressure raised. These clonic 

 convulsions, and the other symptoms probably, are due to 

 stimulation of the medulla oblongata and basal ganglia 

 of the brain. With large doses the stimulation passes 

 into paralysis, and death results from paralysis of respira- 

 tion. 



Sphacelinic acid or Sphacelotoxin especially acts on un- 

 striped muscle through the medium of the sympathetic 

 nerves, increasing its tonus and contraction throughout 

 the body. There is marked contraction of the blood- 

 vessels and a rise of blood-pressure, and in cases of chronic 

 poisoning there is dry gangrene of the extremities. As a 

 result of the insufficient blood supply, a hyaline infiltration 

 of the walls and lumen of the contracted vessels occurs, 

 and this makes the constriction permanent, and so leads to 

 gangrene. This gangrene is especially well seen in fowls, 

 and to a less extent in pigs. In all animals there may be 

 salivation, nausea, vomiting, and purgation, and on post- 

 mortem, signs of gastric irritation with blood extravasation. 

 Cornutine and sphacelinic acid are evidently the principles 

 which cause uterine contraction (Robert). 



Ergotinic acid is a saponin, and so is destroyed by diges- 

 tion, and has little effect except that of a gastric irritant, 

 when given by the mouth. When injected subcutaneously 

 it causes ascending paralysis of the spinal cord and brain 

 both in frogs and mammals, with loss of voluntary motion, 

 paralysis of the vaso-motor centre, and fall of blood- 

 pressure, while respiration and reflex irritability continue. 

 It does not appear to have the power of increasing uterine 

 contractions, and hence cannot be regarded as the most 

 important constituent of ergot. 



The actions of ergot are the combined effects of these 

 three agents. It is quickly absorbed, and in the blood 

 soon exerts its specific action. All unstriped muscular fibre 

 is contracted ; the calibre of blood-vessels is hence dimin- 



