Because thiamin is so essential to energy utilization, general signs of thiamin deficiency include weight loss, impaired feed utilization, and weakness. Some thiamin is also used to form thiamin triphosphate which is thought to have a function in brain cell viability, though its exact role is still unclear. Unfortunately, processing of grains greatly reduces their thiamin content. Thiamin is absorbed through the intestinal wall by both passive diffusion and active, carrier-mediated transport depending on the concentration present. Active transport is highest in the jejunum and ileum, therefore lower gut fermentors that are not corprophagous absorb little of the thiamin produced by intestinal microflora.
Ruminants generally have their thiamin needs met by the thiamin production of the rumen microflora.
Once absorbed, thiamin is transported in the serum chiefly bound to albumin. Back to Index Thiaminases - Definition and Mechanism of Action Thiaminases are enzymes that cleave the thiamin molecule and render it biologically inactive. Type I - the most common form, this type is found in fish, shellfish, ferns and some bacteria. It acts by displacing the pyrimidine methylene group with a nitrogenous base or SH-compound to eliminate the thiazole ring. Once the thiamin molecule is cleaved by a thiaminase the body is incapable of restoring it.