574 NIACIN 



affected areas.^^ The skin temperature may^^ or may not^^ be elevated. In 

 spite of this reaction, blood pressure, pulse, and body temperature are 

 little affected. There is an increased blood flow in the hand and the forearm 

 but little in the leg.^'^ The increase in blood flow is largely in the skin and 

 subcutaneous tissue, there, apparently, being a compensatory decrease in 

 the muscles^^ and the viscera^^- ^° so that there is little change in blood 

 pressure and perhaps only a slight increase in circulating blood volume.-^ 

 Some dilatation of the arteries of the retina may occur,^^ but there is no 

 increase in cerebral blood flow, according to Scheinberg.-^ The latter is 

 somewhat surprising, since flushing doses of nicotinic acid are reported to 

 have a beneficial effect in certain types of headaches.^^- ^^ Nicotinamide 

 and many other related compounds do not cause this flushing reaction,^^ 

 although a few derivatives such as methyl nicotinate, other alkyl nico- 

 tinates, and the alcohol of nicotinamide (Roniacol) do.^^--^ Prior dosage 

 with 30 to 60 g. of glycine is said to prevent or retard the flushing action 

 of nicotinic acid in man.^^-^^ Coramine (N , N-diethylnicotinamide) has a 

 marked stimulant action on the central nervous system. Other nicotinic 

 acid derivatives such as tetrahydrofurfuryl nicotinate'^ have a direct hy- 

 peremic action on the skin. The reported ability of nicotinic acid or nico- 

 tinamide to increase the resistance of rats to anoxia may be related to some 

 of these circulatory effects.-^ 



Although nicotinic acid itself is quite inactive in lowering blood pressure, 

 its methyl ester, the methyl ester of N^-methylnicotinamide, and the methyl 

 ester of N^-methyltetrahydronicotinic acid (arecoline) are, in the order 

 given, quite active in that respect.^ 



D. BLOOD SUGAR 



The extensive and contradictory literature on this subject has been 

 reviewed by Diaz-Rubio and associates.^" Various investigators seem about 



•6 T. D. Spies, W. B. Bean, and R. E. Stone, J. Am. Med. Assoc. Ill, 584 (1938). 

 '^D. I. Abramson, H. H. Katzenstein, and F. A. Senior, Am. J. Med. Sci. 200,96 



(1940). 

 '8 R. A. Murphy, Jr., J. N. McClure, Jr., F. W. Cooper, Jr., and L. D. Crowley, 



Surgery 21, 655 (1950). 

 19 S. Artunkal, Bull. fac. med. Insianbul I, 4024 (1944). 

 2" M. Salvini, Boll. soc. ital. biol. sper. 23, 907 (1947). 

 " M. Salvini and C. Dal Palu, Boll. soc. ital. biol. sper. 24, 986 (1948). 

 "P. Scheinberg, Circulation 1, 1148 (1950). 

 "M. Atkinson, Ann. Internal Med. 21, 990 (1944). 



" J. W. Goldzieher and G. L. Popkin, /. Am. Med. Assoc. 131, 103 (1946). 

 " W. B. Bean and T. D. Spies, /. Am. Med. Assoc. 114, 439 (1940). 

 ^* L. Chevillard, R. Charonnat, and H. Giono, Compt. rend. soc. biol. 144, 194 (1950). 

 " W. Huber, U. S. Pat. 2,431,558 (November 25, 1947). 



28 CIBA Ltd. Swiss Pat. 258,714 (June 1, 1949). 



29 R. M. Calder, Proc. Soc. Exptl. Biol. Med. 68, 642 (1948). 



«" M. Diaz-Rubio, E. Monsalvez, and J. M. Masaguer, Rev. din. espan. 21, 299 (1946). 



