Sialic acid in normal and arthritic human synovial fluids

Abstract

The authors report careful and sign& cant studies of the synovial fluid concentrations of sialic acid, a term which is applied to a group of related compounds first isolated from saliva. The nature of such compounds is reviewed.Since available methods for determining sialic acid are not spec&, two colorimetric procedures were applied. A critical discussion of methodology is presented.Increased concentrations of sialic acid were observed in both the synovial fluids and sera of rheumatoid patients.Le autores reporta meticulose e signscative studios in re le concentration-in le fluido synovial-del si-appellate acido sialic. Iste termino es applicate a un gruppo de inter-relationate compositos prim0 isolate ab specimens de saliva. Le natura de tal compositos es passate in revista.Viste gue le nunc disponibile methodos pro determinar acido sialic non es specific, duo technicas colorimetric esseva applicate. Es presentate un discussion critic del methodologia.Augmentate concentrationes de acido sialic esseva observate in le fluidos synovial e in le seros de patientes rheumatoide.HE BIOLOGIC IMPORTANCE of a group of compounds designated by T the class name sialic acid is becoming increasingly evident. The name is derived from saliva, the source of the first member of the family, which in 1936 was isolated by Blix from bovine submaxillary mucin.'S2 The sialic acid group is composed of N-acetyl, N-glycolyl, and N, 0-diacetyl derivatives of the same compound, now known as neuraminic a~i d .~?~ The substituent groups vary with species of animal.2 The sialic acid isolated from human serum proteins and other human materials is N-acetylneuraminic acid, but the presence of other sialic acids or the loss of substituent groups during isolation is notThe N-acetylneuraminic acid is also known as ovine or 0-sialic acid.Sialic acid has not been investigated previously in synovial fluid although it, or neuraminic acid, has been found in saliva, serum, urine, cerebrospinal fluid, milk and cyst fluids. Derivatives of neuraminic acid have also been isolated from gangliosides, liver, meconium and red blood c e k 5 The pres- 151

Bull Semen Ribonucleases. 1. Purification and Physico-Chemical Properties of the Major Component

“…An analysis for sialic acid performed on the protein by the method of Pigman et al [32] gave a negative result.…”

Sialic Acid in Human Semen and in the Male Genital Tract

“…There is a wide variation in the seminal sialic acid concentration, as there is in the sperm count. This variation of sialic acid levels in semen is considerably greater than it is in serum (19) and synovial fluid (13), and may reflect not only the efficiency of synthesis but the frequency of ejaculation. Hotchkiss found in humans that the total sperm content of an ejaculation was 51 per cent less than one 24 hours previous (17).…”

“…Sialic acid was also assayed by the orcinol method of Werner and Odin (11), by the resorcinol method of Svennerholm (12), and by the diphenylamine procedure of Pigman, Hawkins, Blair and Holley (13).…”

Analytical Methods for Carbohydrates

“…For example, the intensity of the developed color for sialic acids varies with the method employed 1 and also according to the type of sialic acid analyzed, and the use of different color reactions for uronic acids permits identification of some types of uronic acid. More detailed investigation of some of the colorimetric reactions has resulted in reliable quantitative assays for the sugars.…”

“…Acetaldehyde.-6-Deoxyhexoses and 5-deoxypentoses release acetaldehyde on oxidation with periodate. 1 ' 49 The method has also been applied to the determination of other deoxy sugars, 150 and the rate of reaction has been used to characterize the material. Formaldehyde, a typical oxidation product of most sugars, is a common contaminant which must be removed prior to the determination of the acetaldehyde.…”