XI. PHARMACOLOGY 123 



There are strong anatomical and histological parallelisms between the vari- 

 ous forms of renal damage that de\'elop in rats on low choline diets, and 

 lesions in some types of nephrotic conditions and in subacute and chronic 

 stages of Bright's disease. But an> assumption that choline deficiency may 

 play a part in the production of these conditions or that their treatment 

 with lipotropic factors might produce favorable results is completely with- 

 out either experimental or clinical foundation. 



XL Pharmacology 



W. STANLEY HARTROFT, COLIX C. LUCAS, and CHARLES H. BEST 



Choline given parenterally causes a fall in blood pressure (due to dila- 

 tation of peripheral vessels and slowing of the heart); it increases peristalsis 

 of stomach and intestines and increases salivation. Some variability of 

 response has been noted. Choline generally lowers the blood pressure,' but 

 sometimes there is, instead, a rise. It has been claimed that in cats a rise 

 generally follows the fall.- The variable response does not depend upon 

 impurities,'^ as was suggested at one time. Choline acts powerfully upon 

 the autonomic (in\'o]iuitary, vegetative, or visceral) nervous system. Cho- 

 line and most other quaternary ammonium compounds possess in varying 

 degrees three distinct types of pharmacological action: the so-called "mus- 

 carinic," the ''nicotine-like," and the "'curariform'" effects. 



Muscarine, a powerful drug occurring in the poisonous mushroom Ama- 

 nita muscaria, stimulates by direct action (not via the nerve endings) 

 smooth muscles and glands innervated by postganglionic parasympathetic 

 fibers. It causes cardiac slowing, peripheral vasodilation with conseriuent 

 fall in blood pressure, increased peristalsis (with vomiting and defecation), 

 bronchial constriction, salivation, sweating, and miosis. The similarity of 

 the responses of the heart, smooth muscle, and glands to choline (or acetyl- 

 choline) and muscarine led to the adoption of the term "muscarinic action" 

 to describe these effects. Nicotine has long been known to stimulate auto- 

 nomic ganglia before paralyzing them. Choline and acetylcholine produce 

 similar effects. Furthermore, both choline and nicotine have a similar 

 effect (stimulation, then inhi})ition) on skeletal muscle. For this reason the 

 stimulatory action of choline (and other quaternary ammonium com- 

 pounds) on ganglia and voluntary muscles has been called ''nicotine-like." 



' F. W. Motl and W. D. Halliburton, ./. Phy.siol. (Loinlon) 21, xvii-xx (1S<)7). 

 ■-.J. I'al, Z. cxptl. Pathol. Thvidp. 9, 1!»1 206 (1!)11). 



3 R. H. Rcnshaw, F. P. Undorliill, and L. B. Mendel, ./. Pharmacol. Exptl. Therup. 

 3, 457-458 (1912). 



