CHAPTER VII 



Fructose and Fructolysis 



Fructose as a normal constituent of semen. Species differences. Site of 

 formation. Seminal fructose as an indicator of male sex hormone activity; 

 the 'fructose test' and its application to certain problems of sex endocrin- 

 ology. Role of hypophysis. The relationship between blood glucose and 

 seminal fructose. Effect of malnutrition. The enzymic mechanism of fruc- 

 tose formation. Anaerobic and aerobic utilization of carbohydrate by 

 spermatozoa. Pasteur effect and the 'metabolic regulator'. Intermediary 

 reactions in sperm fructolysis and the role of phosphorus-containing 

 coenzymes. 



There has been little precise knowledge about fructose (laevulose) 

 in man and higher animals except the evidence of its occurrence in 

 certain embryonic fluids and in metabolic dysfunctions like fruc- 

 tosuria. The presence of a laevorotatory constitutent in foetal fluids 

 was first noted by Claude Bernard (1855) but its chemical identity 

 was not recognized until some time later when it was shown that 

 fructose was a normal constituent of allantoic and amniotic fluid, 

 foetal blood and the urine of new-born animals (Majewski, 1858; 

 Griiber and Griinbaum, 1904; Paton, Watson and Kerr, 1907; 

 Langstein and Neuberg, 1907; Orr, 1924; Cole and Hitchcock, 

 1946; Bacon and Bell, 1948; Hitchcock, 1949). More recently, the 

 source of foetal fructose was traced to the placenta (Huggett, 

 Warren and Warren, 1951). So far as adult man is concerned, it 

 was believed that in general the occurrence of fructose is restricted 

 to pathological conditions; fructose has been demonstrated in 

 transsudates, and in the urine of diabetics and persons suffering 

 from the peculiar metabolic disorder known as 'spontaneous fruc- 

 tosuria', the aetiology of which remains obscure. In the normal 

 human or animal organism, fructose has been found to be utilized 

 chiefly after enzymic conversion to glucose and glycogen; liver, 

 kidney and the gastro-intestinal tract were shown to be the main 

 sites of this process (Oppel, 1930; Bollman and Mann, 1931; 

 Stewart and Thompson, 1941; Deuel, 1936; Reinecke, 1944). 



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