Seasonal Variations in the Choline Content of Human Serum.

Abstract

In the literature there are but few reports of studies on serum choline content (Guggenheim and Loffler,¹ Sieburg and Patzschke,² Luecke and Pearson,³ and Schlegel⁴).

It appears from these studies that the concentration of choline in human serum ranges from about 0.2 to 2 mg%. As far as has been ascertained, no records are available of studies presenting evidence of seasonal variations in serum choline content. The present study comprises 142 duplicate determinations of serums obtained from both men and women in the period from May 1, 1947 to May 1, 1948. Determinations of choline were made according to the method of Abdon and Ljungdahl-Ostberg⁵ by converting choline into acetylcholine, which physiologically is about 100,000 times as active as choline. Its action was determined biologically on intestines of guinea pigs. The accuracy of the method is 12% on single determinations, 9.4% on duplicate determinations.⁴