However, there are several possibilities including microvascular dysfunction in the blood-brain barrier and alterations in the synthesis, availability, or reuptake of neurotransmitters, such as serotonin (18).
Due to gluconeogenesis in liver, both propionate and lactate can indirectly modulate adipose tissue lipogenesis through increased glucose synthesis, availability, or both.
In these phases synthesis and availability of primary and secondary metabolites including volatile organic compounds (VOC's) is highly variable.
Rapid tryptophan depletion (RTD) is a method that markedly diminishes plasma tryptophan and brain 5-HT synthesis and availability [44, 86], although there is evidence that it does not alter the efflux/release from neurons [87].
Accordingly, exogenous androgen increases aromatization to estradiol, which leads to increases in serotonin synthesis and availability via estrogen receptors (58).
25– 27 Thus, low synthesis and availability of AA have been suggested to mitigate the inflammatory response by altering, for example, eicosanoid levels.
Thus, in the domain of impulsivity, there is evidence for the genetic control in ADHD of the expression of 5-HT receptors, its synthesis and availability [ 24].
Following this reasoning, it could be argued that, at least in our model, CAs synthesis (or availability) participates in the regulation of insulin secretion.
In the pathway for 5-HT synthesis, the availability of Trp determines the rate of 5-HT formation; because the Km values of TPH and AADC are greater than the physiological Trp concentrations, the enzymes are not saturated [ 46, 47].
Changes in elongation rate can also change the pattern of gene expression (Ip et al. 2011), which in turn could influence the synthesis and availability of elongation, termination, and processing proteins.
NO insufficiency e.g., in atherosclerosis, hypertension, arterial thrombotic disorders, heart failure, coronary heart disease, and stroke [ 11, 17, 127– 134]—may reflect an absolute deficit of NO (synthesis), impaired availability of bioactive NO, or enhanced NO inactivation.
