The PDLCs were pre-treated with Wnt5a siRNA (30 nM) or Wnt5 peptide (500 ng/mL) for 2 hours, post-incubated with Tβ4 peptide (1 μg/mL) and 200 μM H2O2 for 48 hours (A-E), and then conditioned medium (CM) was collected. The bar graph shows the fold increase in protein or mRNA expression compared with control. * Statistically significant differences compared with the control, p<0.05. # Statistically significant difference compared with the H2O2-treated group. The data presented were representative of three independent experiments.
The oxytocin peptide is synthesized as an inactive precursor protein from the OXT gene. This precursor protein also includes the oxytocin carrier protein neurophysin I. The inactive precursor protein is progressively hydrolyzed into smaller fragments (one of which is neurophysin I) via a series of enzymes. The last hydrolysis that releases the active oxytocin nonapeptide is catalyzed by peptidylglycine alpha-amidating monooxygenase (PAM).
Virtually all vertebrates have an oxytocin-like nonapeptide hormone that supports reproductive functions and a vasopressin-like nonapeptide hormone involved in water regulation. The two genes are usually located close to each other (less than 15,000 bases apart) on the same chromosome, and are transcribed in opposite directions (however, in fugu, the homologs are further apart and transcribed in the same direction).
Traumatic brain injury (TBI) remains a leading cause of mortality and morbidity worldwide. No effective pharmacological treatments are available for TBI because all Phase II/III TBI clinical trials have failed. This highlights a compelling need to develop effective treatments for TBI. Endogenous neurorestoration occurs in the brain after TBI, including angiogenesis, neurogenesis, synaptogenesis, oligodendrogenesis and axonal remodeling, which may be associated with spontaneous functional recovery after TBI. However, the endogenous neurorestoration following TBI is limited. Treatments amplifying these neurorestorative processes may promote functional recovery after TBI. Thymosin beta4 (Tβ4) is the major G-actin-sequestering molecule in eukaryotic cells. In addition, Tβ4 has other properties including anti-apoptosis and anti-inflammation, promotion of angiogenesis, wound healing, stem/progenitor cell differentiation, and cell migration and survival, which provide the scientific foundation for the corneal, dermal, and cardiac wound repair multicenter clinical trials. Here, we describe Tβ4 as a neuroprotective and neurorestorative candidate for treatment of TBI.
To investigate the effect of Tβ4 peptide on H2O2-induced signaling cascades, the activation states of three mitogen-activated protein kinases (MAPKs; p38, c-Jun N-terminal kinase [JNK] and extracellular signal-related kinase [ERK]) as well as NF-κB p65 were examined in PDLCs. H2O2 treatment induced the phosphorylation of p38, ERK, and JNK MAPK(s) and the nuclear translocation of NF-κB p65 (Fig 5A). Treatment of cells with Tβ4 peptide blocked H2O2-induced nuclear translocation of NF-κB p65 and phosphorylation of ERK and JNK (Fig 5B).
The relationship between oxytocin and human sexual response is unclear. At least two non-controlled studies have found increases in plasma oxytocin at orgasm in both men and women. The authors of one of these studies speculated that oxytocin's effects on muscle contractibility may facilitate sperm and egg transport. Murphy et al. (1987), studying men, found that oxytocin levels were raised throughout sexual arousal and there was no acute increase at orgasm.  A more recent study of men found an increase in plasma oxytocin immediantly after orgasm, but only in a portion of their sample that did not reach statistical significance. The authors noted that these changes "may simply reflect contractile properties on reproductive tissue."
In regards to interventions, one study in treatment resistant depressed persons that combination therapy of 5-HTP with Carbidopa noted that 43 out of 99 (43.4%) patients improved with an average 200mg (variable 50-600mg) dosage of 5-HTP. It has been noted that since Cardidopa is a peripheral decarboxylase inhibitor that can prevent metabolism of monoamines including serotonin that these results are unlikely to reflect monotherapy with 5-HTP, despite being within the 30-45% range sometimes seen with the placebo effect.
At first, the mice showed an irregular smattering of neural impulses when they heard the baby's cries. Then, as the oxytocin kicked in, the signal evolved into a more orderly pattern typical of a maternal brain. The study showed in unusual detail how the hormone changed the behaviour of neurons1. “Oxytocin is helping to transform the brain, to make it respond to those pup calls,” Froemke says.
Jump up ^ Rondanelli M, Opizzi A, Faliva M, Bucci M, Perna S (March 2012). "Relationship between the absorption of 5-hydroxytryptophan from an integrated diet, by means of Griffonia simplicifolia extract, and the effect on satiety in overweight females after oral spray administration". Eating and Weight Disorders. 17 (1): e22–8. doi:10.3275/8165. PMID 22142813.