5- hydroxytryptamine secretion

Bone EA, Best LC, Jones PBB, et al. 1980. The effects of strontium and calcium ions on 5-hydroxytryptamine secretion and thromboxane B2 biosynthesis in washed human platelets. Biochem Soc Trans 8(5) 530-531. 

The compounds helenalin and lla,13-dihydrohelenalin have been shown to inhibit collagen-induced platelet aggregation, thromboxane formation, and 5-hydroxytryptamine secretion in a concentration-dependent manner in human platelets (Schrdder et al. 1990). 

Evidence has been put forward that 6-methoxy-l-methyl-l,2,3,4-tetrahydro-j3-carboline may be a component of animal tissues and may be identical with adrenoglomerulotrophine, a factor controlling aldosterone secretion, which is found in the pineal gland where it occurs together with 5-hydroxytryptamine... 

Although it appears that severe IL-4-regulated enteropathy is not required for immune expulsion of T. spiralis, it is still possible that Th2 cytokines can act in a direct fashion to create an environment unfavourable for intestinal parasites. It remains to be shown directly whether these effects are sufficient to expel parasites. Indeed, there is considerable evidence to support a variety of pathophysiological effects of IL-4 and/or TNF on the gut. These effects may be mediated by factors including cytokines and mast-cell products (e.g. leukotrienes and 5-hydroxytryptamine). 7. spiralis infections result in increased fluid and mucus secretion into the lumen as well as increased intestinal propulsive activity and more rapid intestinal transit (Castro et al, 1979 Russell, 1986 Vermillion and Collins, 1988 Vermillion et al., 1991 Weisbrodt et al, 1994 Barbara et al, 1997). The increased contractility of radial and longitudinal muscle is greater in high-... 

Lundgren O 5-Hydroxytryptamine, enterotox-ins, and intestinal fluid secretion. Gastroenterology 1998,115 1009-1012. 

More than twenty indole derivatives have been identified from bufonid skin extracts. The indolylalkylamines bufotenidine, bufotenine, de-hydrobufotenine, bufo-tionine and serotonin (5-hydroxytryptamine) (Fig. 39.2b) have been identified in skin secretions of Bufo marinus, while the latter four have been detected in parotoid gland secretions (Erspamer 1994 Maciel, Schwartz, Pires Jr, Sebben, Castro, Sousa, Fontes and Schwartz 2003). The concentration of serotonin in the dried secretion of B. marinus was found to equate to approximately 0.1% of the total composition and primarily acts as a vasoconstrictor (Gregerman 1952 Toledo and Jared 1995). 

Ml) Carcinoid tumor. Elevated 5-hydroxyindole acetate (5-HIAA) occurs in carcinoid tumors of the intestine, where argentaffin cells secrete excess 5-hydroxytryptamine (serotonin). The patient experiences flushing, diarrhea, hypotension, and bronchoconstriction. (It is possible that these symptoms may relate to other chemidals also produced by argentaffin cells). 

Serotonin (5-hydroxytryptamine, 5-HT) is synthesised in enterochromaffin cells, largely in the gut, and also extensively taken up into blood platelets from which it is released to have vascular effects. It has complex effects on the cardiovascular system, varying with the vascular bed and its physiological state it generally constricts arterioles and veins and induces blood platelet aggregation it stimulates intestinal and bronchial smooth muscle. Carcinoid tumours secrete serotonin and symptoms may be benefited by serotonin antagonists, e.g. cyproheptadine, methysergide and sometimes by octreotide (see Index). It is a neurotransmitter in the brain. 

Substances or tissue activators, such as histamine, 5-hydroxytryp-tamine, and acetylcholine, which are released in damaged tissue can stimulate the adrenal when injected directly into the adrenal blood supply. Early experiments in denervated limbs in rats suggested that the ascorbic acid depletion of the rat adrenal following injury in the isolated part was due to a humoral agent (Gl), and recent experiments show that 5-hydroxytryptamine has a direct stimulatory effect on aldosterone secretion (J7). 

Fluid and electrolyte loss in cholera patients is closely related to elevated concentrations of cAMP, which can stimulate chloride secretion in intestinal epithelial cells (Field, 1971 Moss and Vaughan, 1988a). There is also evidence for the importance of other substances, such as prostaglandin E2 (PGE2) and 5-hydroxytryptamine (5-HT), in CT-induced secretion (Kaper et al., 1995). Nilsson et al. (1983) reported that 5-HT was released from enterochromaffin cells in the cat small intestine upon CT treatment. 5-HT could then stimulate PGE2 synthesis (Beubler etai, 1989) and activate the enteric nervous system (Ekiund et al., 1984). Cholera toxin also caused release of PGE2 into the lumen of intestinal loops in vitro (Peterson and Ochoa, 1989), via an effect on arachidonic acid formation (Peterson et al., 1990 Reit-meyer and Peterson, 1990). The contribution of these, and perhaps other, CT effects to the pathogenesis of cholera remains to be elucidated (Peterson etai, 1994). 

Beubler E, Kollar G, Soria A, et al. (1989) Involvement of 5-hydroxytryptamine, prostaglandin E2, and cyclic adenosine monophosphate in cholera toxin-induced fluid secretion in the small intestine of rat in vivo. In Gastroenter. 96 368-376. 

Nilsson O, Cassuto J, Larsson L-l, et al. (1983) 5-hydroxytryptamine and cholera secretion A histochemical and physiological study in cats. In Gut 24 543-548. 

SM 3997) is one of the azaspirone group and similar to buspirone. It is a 5-HYDROXYTRYPTAMINE RECEPTOR AGONIST (a partial agonist at the 5HT, receptor subtype) and is a novel ANXIOLYTIC under investigation for the treatment of anxiety and depression. It stimulates prolactin secretion, tandospirone citrate tandospirone. 

Serotonin. Many fruits and vegetables that contain 5-hydroxytryptamine (serotonin), such as bananas, cause an increased excretion of 5-hydroxyindoleacetic acid. Avocados impair glucose tolerance by affectmg insulin secretion. Onions reduce both the plasma glucose and insulin response to glucose. 

The enteric nervous system contains a significant percentage of the body s 5-hydroxytryptamine (serotonin, 5-HT). " Two types of serotonin exists within the gut serotonin type 3 (HT3) and serotonin type 4 (HT4), which are responsible for secretion, sensitization, and motility. FYevious studies show that there is an increase in the postprandial levels of 5-HT in those who suffer from diarrhea-predominant IBS when compared with nonsufferers. Therefore stimulation and antagonism of these serotonin receptors has become a focused area for research on new drug therapies for both diarrhea-and constipation-predominant disease. 

The permissive serotonin hypothesis proposes that serotonin (5-hydroxytryptamine or 5-HT) plays a critical role in modulating brain activity (e.g., stabilization of the catecholamine system and inhibition of dopamine [DA] release), and is low in both mania and depression. L-tryptophan or 5-HT deficiency and changes in the light-dark cycle may result in reduced melatonin secretion from the pineal gland that disrupts the sleep-wake cycle, alters circadian rhythms, and causes seasonal affective changes. ... 

The vascular response to mild injury is biphasic and the initial change is in the small venules (M12) later there is increase in capillary permeability. Various local hormones, such as histamine, 5-hydroxytryptamine, and bradykinin are released, and these mediators could be responsible for the venular change, but blocking them does not prevent exudation. Systemically there is increased secretion of adrenaline (epinephrine) (W5), cortisol (J2), aldosterone (Zl), and ACTH (see Section 8.2). 

It would appear that ACTH plays an important part in the response of cortisol secretion to physical injury, but that aldosterone secretion is more liable to be influenced by other factors, including the renin-angiotensin system (SlOa). Jouan and Samperez (J6) have reported that 5-hydroxytryptamine has a specific action in stimulating aldosterone secretion. 

Early work by Gordon (G14) reported that severe scalds could cause ascorbic depletion of the rat adrenal even when the scalded limb was completely deafferentated. This suggests adrenal stimulation or ACTH release due to a humoral agent. We have already mentioned (Section 8.2) that 6-hydroxytryptamine may have a specific action in stimulating aldosterone secretion (J6), and Johnston (J2) has postulated that other local hormones released after injury, such as histamine and bradykinin, may lead to direct adrenal stimulation. 

Best LC, Bone EA, Russell RGG. 1981. Strontium ions induce production of thromboxane B2 and secretion of 5-hydroxytryptamine in washed human platelets. Biochem Pharmacol 30 635-637. 

In addition to these two classes of substance, the toad poisons obtained from the parotid gland secretions or from the skin may contain cholesterol, ergosterol, epinephrine, norepinephrine, 5-hydroxytryptamine (serotonin) (92), and a series of different vasopressor amines, the bufotonins. 

Serotonin (5-hydroxytryptamine 5-HT) is involved in the regulation of the cardiovascular and respiratory systems, sleep, aggression, sexual behavior, food intake, anxiety, mood, motor output, neuroendocrine secretion, nociception, and analgesia. 

Salamander toxins toxins secreted 1 the skin glands of Salamandra maculosa (European fire salamander) and Salamandra atra (alpine salamander). S.t. include the Salamander alkaloids (see), biogenic amines (tryptamine, S-hydroxytryptamine), and high M, substances that cause skin irritation and hemolysis. 

According to Erspamer " tryptamine has only a slight antidiuretic effect. 5-Hydroxytryptamine, on the other hand, has an antidiuretic effect in rats in doses of 10 pg/kg (Erspamer and Ottolenghi 1349). 20 pg/kg reduce the urine secretion by 40-75% ° for 60-90 min, and a decrease in in the chloride excretion occurs. Passow et showed that 5-hydroxy-... 

In clearance experiments on dogs it was found that the individual phenylalkylamines (phenylethylamine, tyramine, and 3-hydroxytyramine) increased clearance rates at lower dose levels and then reduced them as the dose was increased. Increasing substitution in the parent compound correspondingly increased the potency (Fig. 10). The indolylalkylamines (tryptamine, 5-hydroxytryptamine, and bufotenine) caused an impairment of renal function in the doses used. Among the aliphatic amines, isoamylamine increased, whereas allylamine decreased the renal blood flow and urine secretion to a considerable extent. The injection of combinations of amines (Fig. 11) produced potentiated and additive effects. 

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