Related Experiment Video
Updated: May 14, 2026
08:47
Spectral Confocal Imaging of Fluorescently tagged Nicotinic Receptors in Knock-in Mice with Chronic Nicotine Administration
Published on: February 10, 2012
Excess nicotinamide increases plasma serotonin and histamine levels
Yan-Jie Tian1, Da Li, Qiang Ma
1Institute of Basic Medical Sciences, Medical College, Dalian University, China.
Sheng Li Xue Bao : [Acta Physiologica Sinica]
|February 22, 2013
Summary
High niacin intake, like nicotinamide, can deplete methyl groups essential for neurotransmitter breakdown. This study found excess nicotinamide increased plasma serotonin and histamine levels in healthy subjects.
Area of Science:
- Biochemistry
- Neuroscience
- Nutritional Science
Background:
- Methylation is crucial for degrading monoamine neurotransmitters like serotonin and histamine.
- High niacin intake is common and known to affect the body's methyl group pool.
- The impact of excess niacin on monoamine neurotransmitter degradation remains unclear.
Purpose of the Study:
- To investigate the effect of excess nicotinamide on plasma serotonin and histamine levels in healthy individuals.
- To understand how nicotinamide influences methyl group availability for neurotransmitter metabolism.
Main Methods:
- Nine healthy male volunteers underwent oral loading with 100 mg nicotinamide.
- Blood and urine samples were collected before and after nicotinamide administration.
- Levels of N(1)-methylnicotinamide, 2-Py, betaine, choline, serotonin, and histamine were measured using HPLC and commercial kits.
Main Results:
- Nicotinamide loading increased plasma N(1)-methylnicotinamide and urinary 2-Py excretion.
- A significant decrease in plasma betaine (a methyl-group donor) was observed.
- Plasma serotonin and histamine levels significantly increased five hours post-nicotinamide load.
Conclusions:
- Excess nicotinamide can disrupt monoamine neurotransmitter metabolism by affecting methyl group availability.
- These findings may offer insights into the origins of mental health conditions like schizophrenia and autism.
- Further research is warranted to explore the clinical implications of niacin-induced neurotransmitter imbalances.
Related Concept Videos
01:23Drugs Acting on Autonomic Ganglia: Stimulants
Ganglionic stimulants activate NM nicotinic receptors in autonomic ganglia, falling into two categories: nicotine mimetics [e.g., lobeline, dimethylpiperazine, tetramethylammonium] and muscarinic receptor agonists [e.g., muscarine, methacholine]. The first category's action is rapid and blocked by nicotinic receptor antagonists, while the second category's action is delayed and blocked by atropine-like agents. Nicotine, an alkaloid, affects the heart rate by stimulating sympathetic or...
01:27CNS Depressants: Alcohol and Nicotine
Ethanol, a clear colorless alcohol, has been consumed by humans for millennia, but its effects on the body are far from benign. At lower doses, it induces decreased inhibitions and loquaciousness, leading to its social appeal. However, it can cause severe consequences at higher doses, such as coma and respiratory depression, due to its zero-order elimination kinetics. Chronic ethanol abuse wreaks havoc on multiple organ systems, particularly the CNS and the liver. Abrupt cessation of ethanol...
01:23Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists
Serotonin, a crucial neurotransmitter synthesized by enterochromaffin cells, plays a cardinal role in regulating gastrointestinal (GI) motility. With over 90% of the body's total serotonin in the GI tract, its influence on digestive processes is profound. Serotonin is swiftly released upon various stimuli, such as food boluses or certain drugs, triggering intrinsic sensory neurons in the myenteric plexus and extrinsic vagal and spinal sensory neurons. This leads to the activation of the...
01:21Drugs Affecting Neurotransmitter Release or Uptake
Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking...
01:15Cholinergic Receptors: Nicotinic
Nicotinic receptors are ligand-gated ion channels that are activated by acetylcholine and nicotine. Upon activation, they cause a rapid increase in the permeability of cells to K+, Na+, and Ca2+, followed by depolarization and excitation. They are in the autonomic ganglia, skeletal neuromuscular junction, CNS, and adrenal medulla.
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
01:23Antidepressant Drugs: MAOIs and Other Agents
Atypical antidepressants, including bupropion (Wellbutrin), mirtazapine (Remeron), nefazodone (Serzone), trazodone (Desyrel), and vilazodone (Viibryd), offer unique mechanisms of action. Bupropion weakly inhibits dopamine and norepinephrine reuptake, aiding depression treatment and smoking cessation, with a low risk of sexual dysfunction. Mirtazapine enhances serotonin and norepinephrine neurotransmission, leading to sedation, increased appetite, and weight gain. As a result, it helps treat...