These proteins became of interest in neurobiology with the finding that in the nudibranch (sea slug) Hermissenda crassicornis, the protein Csp24 (conditioned stimulus pathway phosphoprotein-24), with 4 repeats, is involved in simple forms of learning: both one-trial enhancement of the excitability of sensory neurons in the conditioned stimulus pathway, and in multi-trial Pavlovian conditioning. The phosphorylation of Csp24, in common with post-translational modifications of a number of cytoskeleton-related proteins may contribute to actin-filament dynamics underlying structural remodeling of responsive cells.
5-HTP appears to reduce food intake secondary to increasing satiety, although most studies are currently conducted in women (in regards to 5-HTP being related to serotonin, this may be relevant; see our creatine page and the Depression section for more information). At least one study that was mixed gender supports the notion it benefits both genders, however
Evidence for this role of oxytocin come from two types of experiments. First, infusion of oxytocin into the ventricles of the brain of virgin rats or non-pregnant sheep rapidly induces maternal behavior. Second, administration into the brain of antibodies that neutralize oxytocin or of oxytocin antagonists will prevent mother rats from accepting their pups. Other studies support the contention that this behavioral effect of oxytocin is broadly applicable among mammals.
At least one study using an extract of Griffonia simplicifolia (10.24mg giving 2.56mg 5-HTP; confounded with Centella asiatica and Taraxacum officinale at 11.7mg and 4.55mg Paulina cupana and 9.75mg Artichoke extract) taken in three hits, five times a day (40mg 5-HTP total), by 20 overweight or obese females (non-depressive and without eating disorders) for 4 weeks has noted an increase in satiety and reduced binge eating tendencies; the increase in satiety was said to account for the improved weight loss results seen in the experimental group when both were given weight loss advice and diets. This spray has been noted elsewhere to increase satiety (and vicariously through that, body weight) over 2 months in a similar demographic of women.
The first time Ditzen and her colleagues did this experiment they found that for both men and women oxytocin improved communication and lowered cortisol, a stress hormone. But in a recent study published in Social Cognitive and Affective Neuroscience, Ditzen and her colleagues measured salivary alpha-amylase (sAA)—an enzyme tied specifically to social stress—and found that men and women responded differently. Women who got oxytocin showed a decrease in sAA whereas men showed an increase and reported feeling more intense emotions. Counterintuitively, these men were also better at communication during conflict: they smiled more, had more eye-contact and were more open about their feelings. These behaviors are essential for peaceful conflict resolution.
For this study, one of us, Ben Trumble, followed Tsimane men as they went hunting for food. Typically, Tsimane men set out alone or with a partner in the early morning and search in the forest for prey such as wild pigs, deer, monkeys, or the rare tapir. Following long looping trails they might be gone for eight or nine hours, traveling about six miles (ten kilometers). Ben collected saliva samples throughout the hunt in order to measure changes in men’s hormone levels.
Bonding. In the Prairie Vole, oxytocin released into the brain of the female during sexual activity is important for forming a monogamous pair bond with her sexual partner. Vasopressin appears to have a similar effect in males. In people, plasma concentrations of oxytocin have been reported to be higher amongst people who claim to be falling in love. Oxytocin has a role in social behaviors in many species, and so it seems likely that it has similar roles in humans.6
Oxytocin production is controlled by a positive feedback mechanism. This mechanism allows the release of the oxytocin hormone when a trigger occurs. The hormone then causes an action in the body, such as the letdown of milk or the start of labor contractions, which signals more production of oxytocin. The feedback cycle continues until the action, such as childbirth or feeding the baby, is complete.
A study published last year in Biological Psychiatry was the first to assess whether people with variations in their oxytocin-receptor gene have a harder time maintaining romantic relationships than those who don’t. Hasse Walum, a graduate student at Karolinska Institute in Stockholm, and his colleagues took advantage of Swedish twin studies that included thousands of participants, their genetic information and their answers to questions about how affectionate they were with their romantic partners. They found that women with a specific variation weren’t as close to their partners as women without it: they kissed their partners less and didn’t desire physical proximity as often. These women were also more likely to report having had a marital crisis. Although researchers don’t know exactly how this variation affects the oxytocin system, it may result in a lower number of oxytocin receptors in the brain. People with fewer receptors would be less sensitive to the hormone’s effects.
Therefore, this study was designed to investigate whether Tβ4 was up-regulated in patients with periodontitis, and this study was also designed to investigate whether Tβ4 inhibition or activation suppressed the osteoclastic differentiation in mouse bone marrow-derived macrophages (BMMs) and inflammatory response in periodontal ligament cells (PDLCs) as well as on their signaling pathways.
Thymosin beta 4 (Tβ4) is a highly conserved, naturally occurring, water-soluble regenerative peptide that is found in all tissues and in all cell types, except red blood cells (Goldstein, Hannappel, Sosne, & Kleinman, 2012; Goldstein & Kleinman, 2015). It is also found in the blood and in other body fluids, including tears, saliva, cerebrospinal fluid, and wound fluids (Badamchian et al., 2007; Huang, Wang, Barnes, & Elmets, 2006; Mohring, Kellmann, Jurgens, & Schrader, 2005). Both platelets and leukocytes release Tβ4 into the wound fluid such that the final concentration is 13 μg/mL (Fromm, Gunne, Bergman, et al., 1996; Hannappel & van Kampen, 1987).
Oxytocin has been shown to help people with autism improve their ability to recognize emotion, and Wallum found that the same receptor variant that increases risk for marital crisis in women is linked to social problems in girls. These include trouble getting along with others and a preference for being alone. This and Feldman’s work on oxytocin’s importance for the mother–child bond suggests that the hormone is more involved in the communication component of love between couples than the romantic component of love.
FGF-2 and VEGF enhance angiogenesis in chronic wounds (Greenalgh, 1996; Kirchner et al., 2003). Thymosin β-4 increases angiogenesis, consistent with its ability to induce epicardial cells to differentiate into endothelial and smooth muscle cells of coronary vessels (Chapter 7). L-arginine enhances angiogenesis in chronic wounds by enhancing the production of endothelial nitric oxide and improving blood flow (Shi et al., 2003). L-arginine also plays a role in the formation of proline, which is essential for the structure of collagen molecules. ChrysalinTM, a synthetic peptide representing the portion of human thrombin that binds to the surface of endothelial cells, doubled the incidence of complete healing of diabetic foot ulcers in human patients (Fife et al., 2007). Another molecule used to treat peripheral artery disease, pentoxifylline, was reported to improve blood flow in chronic wounds by reducing blood viscosity (Falanga et al., 1999).
The studies that have been conducted have determined that this peptide is potent and that it occurs totally naturally. It does help to repair wounds using its anti-inflammatory characteristics. Unlike with growth factors and other repair factors, this peptide increases the migration of endothelial and keratinocyte. It also does not conjoin to extracellular matrixes and is noted as having a molecular weight that is very low, which enables it to travel far distances within tissues.
To evaluate the indirect effect of Tβ4 peptide on RANKL-induced osteoclastogenesis, mouse BMMs were incubated with RANKL and CM, prepared from HPDLCs treated with H2O2 and different concentrations of Tβ4, and allowed to differentiate into osteoclasts. As shown in Fig 6, Tβ4 peptide dose-dependently decreased the number of osteoclasts and TRAP activity. To determine whether the reduction in osteoclast generation by Tβ4 could be due to effects of Tβ4 peptide on viability of the BMMs, a cytotoxicity assay was performed. The viability of BMMs was not significantly affected by Tβ4 peptide (data not shown).
“L-5-Hydroxytryptophan significantly reduced the reaction to the panic challenge in panic disorder patients, regarding subjective anxiety, panic symptom score and number of panic attacks, as opposed to placebo. No such effect was observed in the healthy volunteers. L-5-Hydroxytryptophan acts to inhibit panic, which supports a modulatory role of serotonin in panic disorder.”
A: While it is possible there is an interaction, it most likely is not severe or life-threatening. Keep in mind that the "T" in HTP stands for tryptophane, which is an essential amino acid that your body processes routinely. The most common interaction involved with 5-HTP is with antidepressants or other medications that are intended to affect brain chemistry, as 5-HTP is converted into serotonin, an important brain chemical that helps regulate mood.
Growth factors play an important role is enhancing structural repair of chronic wounds (Robson, 1997). KGF-2 (Robson et al., 2001), TGF-β (Robson et al., 1995), PDGF-BB (Mustoe et al., 1994; Kiritsy et al., 1995; Smiell et al., 1999), β-NGF (Muangman et al., 2004) have been shown to enhance re-epithelialization (Greenalgh, 1996 for review). The KGF-1 gene has been shown to improve cutaneous wound healing in a septic rat model when delivered in a plasmid (Lin et al., 2006). The PDGF-B gene carried in a plasmid mixed with a bovine collagen gel was reported to accelerate closure of patient diabetic ulcers (Mulder et al., 2009; Blume et al., 2011). KGF-2, PDGF-BB and FGF-L are commercially available as RepiferminTM, RegranexTM, and Trafermin to treat human chronic wounds. Data for the effects of PDGF-BB on back wounds of diabetic mice and for the effects of KGF-2 on chronic venous ulcers in patients is tabulated in Tables 10.3 and 10.4. Thymosin β4 accelerated keratinocyte migration in the wounds of old diabetic mice (Philp et al., 2003).
Tb4 has other effects that are needed in healing and repair of damaged tissue. It is a chemo-attractant for cells, stimulates new blood vessel growth (angiogenesis), downregulates cytokines and reduces inflammation, thus protecting newly formed tissue from damaging inflammatory events. Tb4 has been shown to reduce free radical levels (with similar efficiency as superoxide dismutase), decrease lipid peroxidation, inhibit interleukin 1 and other cytokines, and decrease inflammatory thromboxane (TxB2) and prostaglandin (PGF2 alpha).
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About ten years ago, psychology studies started to show that single doses of oxytocin, delivered through an intranasal spray, could promote various aspects of social behaviour in healthy adults. People who inhaled oxytocin before playing an investment game were more willing to entrust their money to a stranger than were placebo-treated players10. A dose of the hormone also increased the amount of time that people spent gazing at the eye region of faces11, and improved their ability to infer the emotional state of others from subtle expressions12.
Differences among groups were analyzed using a one-way analysis of variance combined with the Bonferroni test. The relative intensities of mRNA and protein bands were assayed using Quantity-One software (Bio-Rad Co., Hercules, CA, USA); results were normalized to the mRNA and protein levels of beta-actin. All values were expressed as mean ± standard deviation. Differences were considered significant at p < 0.05.
What we noticed was that all the rats that had received oxytocin straight into their brain immediately prior to being given alcohol, were up and moving about and seemed to be completely sober. Whereas all of the rats that had just been given the alcohol were, as we would predict from the dose that we were giving them, quite drunk. And so we thought, 'Wow, what's going on here?' It was almost as though the oxytocin was blocking the intoxicating effects of the alcohol.
In women, oxytocin is responsible for signaling contractions of the womb during labor. The hormone stimulates the uterine muscles to contract, so labor begins. It also increases the production of prostaglandins, which move labor along and increases the contractions even more. Because of this effect, synthetic oxytocin (pitocin) is sometimes used to induce a woman to start labor if she cannot start naturally, or it can be given to make contractions stronger if a woman's labor is slowing.
Jump up ^ Wei D, Lee D, Cox CD, Karsten CA, Peñagarikano O, Geschwind DH, Gall CM, Piomelli D (November 2015). "Endocannabinoid signaling mediates oxytocin-driven social reward". Proceedings of the National Academy of Sciences of the United States of America. 112 (45): 14084–9. Bibcode:2015PNAS..11214084W. doi:10.1073/pnas.1509795112. PMC 4653148. PMID 26504214.
Jump up ^ Gauquelin G, Geelen G, Louis F, Allevard AM, Meunier C, Cuisinaud G, Benjanet S, Seidah NG, Chretien M, Legros JJ (1983). "Presence of vasopressin, oxytocin and neurophysin in the retina of mammals, effect of light and darkness, comparison with the neuropeptide content of the neurohypophysis and the pineal gland". Peptides. 4 (4): 509–15. doi:10.1016/0196-9781(83)90056-6. PMID 6647119.
Melanotan II was originally developed as a treatment for sexual dysfunction. However, this was abandoned when the metabolite bremelanotide was developed instead for treatment of haemorrhagic shock. Melanotan II is usually injected subcutaneously for the purposes of sunless tanning, appetite suppression, inducing sexual desire and penile erection and other conditions such as rosacea and fibromyalgia. There are also dose forms available for nasal administration. The therapeutic dose is considered to be 0.01 mg/kg.
As reactive oxygen species (ROS) have been implicated in the pathogenesis of periodontitis , we examined whether H2O2 could down-regulate or up-regulate Tβ4 expression in PDLCs. As shown in Fig 1A and 1B, Tβ4 mRNA and protein expressions were down-regulated by H2O2 in a time- and concentration-dependent manner. Because maximal Tβ4 mRNA and protein expressions were achieved with 200 μM H2O2 within 48 hours in PDLCs, this concentration was used in subsequent experiments.
Potential side effects of 5-HTP include heartburn, stomach pain, nausea, vomiting, diarrhea, drowsiness, sexual problems, vivid dreams or nightmares, and muscle problems. Because 5-HTP has not been thoroughly studied in a clinical setting, possible side effects and interactions with other drugs are not well known. According to the US National Institute of Health TOXNET, 5-HTP has not been associated with serotonin syndrome or any serious adverse events in humans. Across multiple studies, 5-HTP also been reported to not cause any noticeable hematological or cardiovascular changes. 5-HTP also has not been associated with eosinophilia.