Methods of Determining Functions of Endocrine Organs 9 



doses effects are produced upon metabolism, including an increase of N- 

 secretion and an increase of O 2 intake and of CO., output, with reduction 

 of body fat. Buccal administration of pituitary extracts or pituitary 

 gland substance is also stated to yield beneficial results in cases of deficiency 

 of pituitary secretion, although in normal individuals no effect may be 

 apparent. Similarly, buccal administration of suprarenal extract gives 

 little, result in normal individuals, but both in Addison's disease and in 

 certain other affections beneficial effects have been recorded. 



Administration by Subcutaneous or Intramuscular Injection. As 

 with drugs, the effects of administering the animal autacoids by hypodermic 

 injection are usually more rapid and more marked than with buccal ad- 

 ministration, although in some cases the difference is not striking. But 

 Meltzer and Auer have shown that if extract of the medulla of the supra- 

 renals, or of the posterior lobe of the pituitary body, are administered by 

 intramuscular injection absorption being promoted by gentle massage 

 they rapidly cause their characteristic effects. Probably the reason why 

 these extracts when given by hypodermic injection produce little general 

 result although the local effects in causing vasoconstriction may be very 

 marked is that the autacoid is rapidly destroyed in the body; so that 

 when absorbed slowly it is got rid of before any excess is able to accumulate 

 in the blood. This applies onty to moderate doses and to the immediate 

 effects. Secondary effects may be seen with large doses, and these may be 

 of a marked character. 



Intravenous Injection. The immediate effects if any of the animal 

 autacoids are, as with drugs, unfailingly exhibited as the result of the in- 

 jection into a vein of the extracts containing them. In this manner can be 

 shown the action of extract of thyroid in causing a marked but evanescent 

 depression of the blood-pressure : the various effects of extract of suprarenal 

 medulla ; such as contraction of blood-vessels with raising of blood-pressure, 

 acceleration of pulse, sometimes preceded or followed by retardation, flow 

 of saliva, erection of hairs, dilatation of pupil, retraction of third eyelid, 

 and protrusion of eyeball, contraction of uterus, vas deferens, and seminal 

 vesicles, inhibition of gastric and intestinal movements and of the bladder : 

 as well as those produced by extracts of the posterior lobe of the pituitary, 

 such as contraction of the blood-vessels with slowing of the heart, increase 

 of secretion from the kidneys, outflow of milk from the mammary gland, 

 contraction of the uterus, of the intestines, and of plain muscle in general. 



A caution must be entered against the too hasty conclusion that a particular 

 effect obtained in injecting an organ extract is a specific effect due to an autacoid 

 substance. Especially is this warning necessary in experiments in which the blood- 

 pressure is employed as the gauge of activity. For there are few organs which 

 yield extracts that are absolutely inert when tested by intravenous injection. This 

 applies to many glandular and lymphatic structures, extracts of which generally 

 cause a rapid fall of blood-pressure, usually speedily recovered from. The depressor 

 effect is not dependent upon the presence of nucleo-proteins in the extract, as was 



