• Archives of Obesity and Metabolism
• /
• v.3 no.1
• /
• pp.35-42
• /
• 2024

Serotonin, a biogenic amine widely found in many organisms, functions as both a neurotransmitter and hormone. Although serotonin is involved in various physiological processes, this study aimed to review its role in energy metabolism. Given that serotonin cannot cross the blood-brain barrier and is synthesized by two different isoforms of tryptophan hydroxylase in the central nervous system (CNS) and peripheral tissues, it is reasonable to assume that serotonin in the CNS and peripheral tissues functions independently. Recent studies have demonstrated how serotonin influences energy metabolism in metabolic target organs such as the intestines, liver, pancreas, and adipose tissue. In summary, serotonin in the CNS induces satiety and appetite suppression, stimulates thermogenesis, and reduces body weight. Conversely, serotonin in the periphery increases intestinal motility, stimulates gluconeogenesis in the liver, suppresses glucose uptake by hepatocytes, promotes fat uptake by liver cells, stimulates insulin secretion while suppressing glucagon secretion in the pancreatic islets, promotes lipogenesis in white adipose tissue, inhibits lipolysis and browning of white adipose tissue, and suppresses thermogenesis in brown adipose tissue, thereby storing energy and increasing body weight. However, considering that most experimental results were obtained using mice and conducted under specific nutritional conditions, such as high-fat diets, whether serotonin acts in the same way in humans, whether it will act similarly in individuals with normal versus obese weights, and whether its effects vary depending on the type of food consumed, remain unknown.

• Korean Journal of Food Science and Technology
• /
• v.42 no.2
• /
• pp.142-146
• /
• 2010

Relatively large amounts of GABA can be produced by the fermentation of rice bran. Therefore, this study was conducted to investigate the effects of GABA on the secretion of melatonin and serotonin for the development of a sleep inductive compound. The secretion levels of melatonin and serotonin from mice were found to be $3.425{\pm}0.182\;pg/mL$ and $5.37{\pm}0.963\;ng/mL$, respectively, in response to feeding 120 mg/mL of GABA while they were $2.607{\pm}0.41\;pg/mL$ in the control. The secretion of both melatonin and serotonin was increased up to the 13.51% and 34.99%, respectively, when compared to the negative control. However, the feeding of milk alone did not have a great effect on the melatonin and serotonin secretions. Conversely, feeding of milk with GABA enhanced the secretion of serotonin. The amounts of both melatonin and serotonin secreted increased with respect to the increase in GABA concentrations during feeding. Interestingly, the induction level of melatonin was relatively higher than that of serotonin in response to feeding 120 mg/mL of GABA. This is the first study to report that GABA has an ability to induce sleep related hormones in mice; therefore, it has the potential for use as a natural sleep aid.

• Genomics & Informatics
• /
• v.5 no.2
• /
• pp.77-82
• /
• 2007

Serotonin (5-HT), the endogenous nonselective 5-HT receptor agonist, activates the inositol-1,4,5-triphosphate/calcium $(InsP3/Ca^{2+})$ signaling pathway and exerts both stimulatory and inhibitory actions on cAMP production and neuromodulin secretion in rat hypothalamic neurons. Specific mRNA transcripts for 5-HT1A, 5-HT2C and 5-HT4 were identified in rat hypothalamic neurons. These experiments were supported by combined techniques such as cAMP and a $Ca^{2+}$ assays in order to elucidate the associated receptors and signaling pathways. The cAMP production and neuromodulin release were profoundly inhibited during the activation of the Gi-coupled 5-HT1A receptor. Treatment with a selective agonist to activate the Gq-coupled 5-HT2C receptor stimulated InsP3 production and caused $Ca^{2+}$ release from the sarcoplasmic reticulum. Selective activation of the Gs-coupled 5-HT4 receptor also stimulated cAMP production, and caused an increase in neuromodulin secretion. These findings demonstrate the ability of 5-HT receptor subtypes expressed in neurons to induce neuromodulin production. This leads to the activation of single or multiple G-proteins which regulate the $InsP3/Ca^{2+}/PLC-{\gamma}$ and adenyl cyclase / cAMP signaling pathways.

• The Korean Journal of Physiology and Pharmacology
• /
• v.15 no.5
• /
• pp.307-312
• /
• 2011

It has been rereported that axons which display 5-hydroxytryptamine (5-HT) immunoreactivity are abundant in the pancreas and the majority of serotonergic axons terminate within intrapancreatic ganglia, islet and acini. This histological result strongly suggests that intrapancreatic serotonergic nerves could affect to the pancreatic endocrine and exocrine secretion. Thus, this study was aimed to investigate whether intrapancreatic serotonergic nerves could affect pancreatic exocrine secretion and an action mechanism of the intrapancreatic serotonergic nerves. The rats were anesthetized with a single injection of urethane. The median line and the abdominal aorta was carefully dissected and cannulated with PE-50 tubing just above the celiac artery, and then tightly ligated just below the superior mesenteric artery. The pancreatic duct was also cannulated with Tygon microbore tubing. With the addition of serotonin, pancreatic volume flow and amylase output were significantly inhibited electrical field stimulation (EFS). On the other hand, pancreatic volume flow and amylase output were significantly elevated in EFS with the addition of spiperone. EFS application, however, pancreatic volume flow and amylase output had no significant change in cholecystokinin (CCK) alone when serotonin was applied under a 5.6 mM glucose background. Pancreatic volume flow and amylase output under 18 mM glucose background were significantly elevated in CCK plus serotonin than in CCK alone. These data suggest that intrapancreatic serotonergic nerves play an inhibitory role in pancreatic exocrine secretion and an important role in the insulin action or release.

• Applied Chemistry for Engineering
• /
• v.24 no.6
• /
• pp.605-610
• /
• 2013

Gamma-aminobutyric acid (GABA) is a non-protein amino acid widely present in organisms, which has shown several important physiological functions such as neurotransmission, hypotension induction, as well as diuretic and tranquilizer effects. They have also been extensively used in food industry. GABA contents in the grain and brown rice are about 1~4 mg/100 g and 4~8 mg/100 g, respectively but it is difficult to expect physiological activity from such low amounts of natural food intake. We investigate the effects of GABA-coated rice on the secretion of melatonin and serotonin which both have been used as sleep inductive compounds. As a result, the secretion of melatonin and serotonin from mice were found to be $3.578{\pm}0.158pg/mL$, $5.918{\pm}0.169ng/mL$ respectively. The melatonin and serotonin in mice increased significantly up to the 8.7 and 22.8 times respectively, when compared to that of the rice, but there was no cumulative effects. Due to the continuous intake of GABA-coated rice, which was developed as a functional food nutrient, inductive effects of melatonin and serotonin from general rice could be achieved and also the similar effect as taking up directly 25 mg/mL of GABA could be obtained.

• Korean Journal of Pharmacognosy
• /
• v.53 no.2
• /
• pp.64-69
• /
• 2022

When blood vessels are damaged, a rapid hemostatic response should occur in order to lower blood loss and keep normal circulation, and platelet activation and aggregation are essential. Nevertheless, abnormal or excessive platelet aggregation can be a reason of cardiovascular diseases including thrombosis, atherosclerosis, and stroke. Therefore, the screening for a substance which can regulate platelet activation and suppress aggregation reaction is very important for treatment and prevention of cardiovascular diseases. Artemether is a methyl ether derivative of artemisinin, which is isolated from the antimalarial plant Artemisia annua, but research on platelet aggregation or its mechanisms is still insufficient. This study identified the effects of artemether on U46619-induced human platelet aggregation and their granule secretion (ATP and serotonin release). In addition, the effects of artemether on the phosphorylation of PI3K/Akt or MAPK, which are related to signal transduction in platelet aggregation, were studied. As the results, artemether significantly lowered PI3K/Akt and MAPK phosphorylation, which inhibited platelet aggregation through granule secretion (ATP and serotonin release) dose-dependently. Therefore, we suggest that artemether is an antiplatelet substance that regulates PI3K/Akt and MAPK pathway and is of value as a therapeutic and preventive agent for platelet-derived cardiovascular diseases.

• Journal of Applied Biological Chemistry
• /
• v.63 no.2
• /
• pp.131-136
• /
• 2020

When blood vessels are damaged, a fast hemostatic response should occur to minimize blood loss and maintain normal circulation. Platelet activation and aggregation are essential in this process. However, excessive platelet aggregation or abnormal platelet aggregation may be the cause of cardiovascular diseases such as thrombosis, stroke, and atherosclerosis. Therefore, finding a substance capable of regulating platelet activation and suppressing agglutination reaction is important for the prevention and treatment of cardiovascular diseases. 6,7-Dimethoxy-2H-chromen-2-one (Scoparone), found primarily in the roots of Artemisia or Scopolia plants, has been reported to have a pharmacological effect on immunosuppression and vasodilation, but studies of platelet aggregation and its mechanisms are still insufficient. This study confirmed the effect of scoparone on collagen-induced human platelet aggregation, TXA₂ production, and major regulation of intracellular granule secretion (ATP and serotonin release). In addition, the effect of scoparone on the phosphorylation of the phosphoproteins PI3K/Akt and mitogen-activated protein kinases (MAPK) involved in signal transduction in platelet aggregation was studied. As a result, scoparone significantly inhibited the phosphorylation of PI3K/Akt and MAPK, which significantly inhibited platelet aggregation through TXA₂ production and intracellular granule secretion (ATP and serotonin release). Therefore, we suggest that scoparone is an antiplatelet substance that regulates the phosphorylation of phosphoproteins such as PI3K/Akt and MAPK and is of value as a preventive and therapeutic agent for platelet-derived cardiovascular disease.

• Journal of Ginseng Research
• /
• v.10 no.2
• /
• pp.123-132
• /
• 1986

The pepsinogen secretion was stimulated by the cholecystokinin, caerulein, isoproterenol, and carbachol, respectively. But it was increased slightly and returned to control level by the combiantions of total saponin with each above the agents. Even though the atropine had the inhibition effect, the pepsinogen secretion was recovered to normal level from depressed condition by the combination of the atropine with total saponin. Propranolol showed the same pattern as atropine, too. On the other hand, the pepsinogen secretion was stimulated by the DBcAMP alone, but decreased to control level by the combination with the total saponin. In the case of DBcGMP, the pepsinogen secretion was decreased by itself, but stimulated the above control level by the combination with total saponin. Histamine alone had little effect on the pepsinogen secretion, but when combinated with total saponin, the pepsinogen secretion was increased. Serotonin alone and with total saponin, had no effect respectively, From the above results, the total saponin may have the normalization action stimulating or decreasing the pepsinogen secretion to the control level.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.123-123
• /
• 2018

Premenstrual syndrome (PMS) is a common disorder affecting the emotional and physical health of women during certain periods of the menstrual cycle. Many researchers who have previously studied PMS have believed that PMS is associated with changes in sex hormones and serotonin levels at the beginning of the menstrual cycle. However, recent studies suggest that progesterone/estrogen imbalance and elevation of prolactin-induced by dopamine low-secretion play a crucial role in increasing PMS symptoms. Because of this, we have focused on mitigating PMS symptoms through the mechanism of prolactin secretion inhibition by dopamine receptor activation. The inhibition of prolactin secretion by 61-kinds of medicinal herb extracts was investigated in GH3 pituitary cells. Among them, Inula heleniun L. root extract (IHE) showed excellent prolactin secretion inhibitory effect. IHEs were prepared using 30, 50, and 70% ethanol. And the yield, cytotoxicity, dopamine receptor activity and inhibition of prolactin secretion of each extract were measured. Through a series of experiments, we found that prolactin secretion was significantly reduced (P<0.01) by the components present in IHE and that dopamine receptor regulation was possible (P<0.05). Considering yield and safety, we suggest the use of 30% ethanol IHE in the development of PMS symptom relief products.

• Parasites, Hosts and Diseases
• /
• v.31 no.1
• /
• pp.13-20
• /
• 1993

The histological change of the billary mucosa in clonorchiasis is characterized as adenomatous hyperplasia, and cross-sectioned mucosa looks like intestinal mucosa. In addition to the glandular hyperplasla, the metaplasia of mucin secreting cells is also known. The present study investigated the presence of intestinal secretion from the biliary mucosal cells of rabbits and rats with Clonorchis sinensis infection. The rabbit was infected with 300 and the rat was infected with 100 metacercariae of C. sinensif. A part of the animals were followed up after praziquantel treatment. The rabbit livers were prepared for histochemistry to observe any endocrine secretion and the bile duct mucosa of the mice was processed far the activity of brush border membrane (BBM)-bound enzymes of the small intestine. Immunohistochemistry with the polyclonal antibodies and biotin-streptavidin-peroxidase staining kit showed no positive cells for gastrin and secretin, but a few cells were positive for serotonin. The proliferated billiw mucosa of the mice revealed no activity of dissaccharidases and aminopeptidase. Only alkaline phosphatase activity was found both in the control and the infected. The hyperplastic billary mucosal cells showed no gastrointestinal secretory functions. The serotonin secreting cells may be one of the inflammatory cells.