response to vitamin B1

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a vitamin B1 stimulus. [GOC:pz]

Vitamin B1, also known as thiamine, is an essential nutrient that plays a crucial role in carbohydrate metabolism and various other cellular processes. The body cannot synthesize thiamine and must obtain it from dietary sources. Thiamine deficiency, also known as beriberi, can lead to severe neurological and cardiovascular complications.

Upon ingestion, thiamine is absorbed in the small intestine and transported to various tissues throughout the body. The primary active form of thiamine is thiamine pyrophosphate (TPP), which is a coenzyme for several key enzymes involved in carbohydrate metabolism. These enzymes include pyruvate dehydrogenase (PDH), alpha-ketoglutarate dehydrogenase (α-KGDH), and transketolase.

**PDH** catalyzes the conversion of pyruvate to acetyl-CoA, a key step in the breakdown of glucose for energy production. This reaction is essential for the citric acid cycle and oxidative phosphorylation, the primary pathways for ATP generation.

**α-KGDH** is another crucial enzyme involved in the citric acid cycle, catalyzing the oxidative decarboxylation of α-ketoglutarate. This step is crucial for the efficient production of ATP and the generation of reducing equivalents (NADH) for electron transport.

**Transketolase** is a key enzyme in the pentose phosphate pathway, a metabolic pathway that generates NADPH and the precursor for nucleotide biosynthesis. Thiamine deficiency can lead to impaired activity of transketolase, resulting in a decrease in NADPH production and impaired nucleotide biosynthesis.

**Cellular response to thiamine:**

1. **Thiamine uptake:** Cells take up thiamine through specific transporters. Once inside the cell, thiamine is phosphorylated to thiamine monophosphate (TMP) by thiamine pyrophosphokinase.
2. **TPP synthesis:** TMP is further phosphorylated to TPP by thiamine pyrophosphokinase. TPP is the active coenzyme form of thiamine.
3. **Enzymatic activity:** TPP is required for the activity of several key enzymes involved in carbohydrate metabolism, including PDH, α-KGDH, and transketolase.
4. **Metabolic regulation:** The activity of these enzymes is tightly regulated, ensuring adequate energy production and biosynthesis pathways.
5. **Cellular signaling:** Thiamine deficiency can trigger cellular signaling pathways that contribute to the pathogenesis of beriberi.

**Clinical implications:**

Thiamine deficiency can lead to beriberi, characterized by neurological and cardiovascular complications. Neurological symptoms include peripheral neuropathy, Wernicke's encephalopathy, and Korsakoff's syndrome. Cardiovascular symptoms include tachycardia, arrhythmias, and heart failure.

**Dietary sources:**

Rich sources of thiamine include whole grains, legumes, nuts, seeds, and pork. Supplementation with thiamine is recommended in individuals with a high risk of deficiency, such as alcoholics and individuals with malabsorption disorders.

**Summary:**

Thiamine is an essential nutrient that plays a crucial role in carbohydrate metabolism. It is a coenzyme for several key enzymes involved in energy production and biosynthesis. Thiamine deficiency can lead to beriberi, characterized by neurological and cardiovascular complications. Ensuring adequate thiamine intake is essential for maintaining optimal health.'
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Proteins (2)

Compounds (35)