Movement thiamine

Vitamin B1 (thiamine) has the active form, thiamine pyrophosphate. It is a cofactor of enzymes catalyzing the conversion of pyruvate to acetyl CoA, a-ketoglutarate to succinyl CoA, and the transketolase reactions in the pentose phosphate pathway. A deficiency of thiamine causes beriberi, with symptoms of tachycardia, vomiting, and convulsions. In Wernicke-Korsakoff syndrome (most common in alcoholics), individuals suffer from apa thy, loss of memory, and eye movements. There is no known toxicity for this vitamin. 

Thiamin deficiency in alcoholics may be caused by decreased intake, reduced absorption, and impaired ability to use ihe absorbed vitamin. The ataxia and ocular symptoms associated with the deficiency in alcoholics are known as Wernicke s disease. Vitamin therapy can provide relief from nystagmus within a few hours of treatment and from ataxia within several weeks. The treatment of alcoholics also involves the supply of other nutrients lacking in the diet, such as folate, vitamin B12, and protein. Left imtreated, patients suffering from Wernicke s disease continue to develop Korsakoff s psychosis, which involves amnesia and confusion. Only about 25% of patients with Korsakoff s psychosis can be completely cured by thiamin treatment, which must be continued for a few weeks or months. The two conditions just described constitute the Wemicke-Korsakoff syndrome. The S5mdrome was named after two researchers. Karl Wernicke, a German, noted impaired or paralyzed eye movements and imstable walking and disorientation in his patients, most of whom were alcoholics. Polyneuropathy, a weakness of the hands, calves, and feet, was also noted. Sergei Korsakoff, a Russian, observed amnesia and confusion and an inability to learn new names or tasks in alcoholic patients. 

Mutations in thiamin diphosphate dependent enzymes, in particular pyruvate dehydrogenase, may lead to Leigh s disease or subacute necrotizing encephalomyelopathy. This severe, inherited syndrome is characterized by movement disorders and, at later stages, by lactic acidosis. The children affected have a life expectancy of less than three years. 

Beriberi is a nervous system disorder caused by a thiamine deficiency. Wet beriberi primarily affects the cardiovascular system, while dry beriberi affects the nervous system. Wet beriberi can also be characterized by vasodilation, peripheral oedema, shortness of breath and swelling of the lower legs. Dry beriberi causes partial paralysis resulting from damaged peripheral nerves and can be characterized by difficulty walking, loss of muscle function, mental confusion and involuntary eye movements. 

Bettendorff, L., Mastrogiacomo, F., LaMarche, J., Dozic, S., and Kish, S.J., 1996b. Brain levels of thiamine and its phosphate esters in Friedreich s ataxia and spinocerebellar ataxia type 1. Movement Disorders. 11 437-439. 

Abscisins and Thiamine. The few studies on ABA movement in shoot sections has likewise led to contradictory results. Dorffling and Bottger (1968) and Milborrow (1968) found fast (20-30 mm h ) ABA movement through petiole... 

Jacobs WP, De Muth PJ (1977) Non-polar movement of thiamine in stems of tomato and roots of pea. Bot Gaz 138 266-269... 

Krul WR (1977) Differences in velocity of auxin movement obtained by intercept and peak arrival methods. Physiol Plant 41 259-264 Krul WR, Colclasure GC (1977) Effect of galactose and other monosaccharides on lAA movement in bean hypocotyl segments. Physiol Plant 41 249-253 Kruszewski SP, Jacobs WP (1974) Polarity of thiamine movement through tomato petioles. Plant Physiol 54 310-311... 

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