The correct answer is neurotransmitters.
Why neurotransmitter is not transported by blood ?
Most neurotransmitters present in the blood do not enter the brain because of their low lipid solubility and lack of specific transport carriers in the lumina membrane of the capillary endothelial cell.
What type of transport do neurotransmitters use?
Vesicular transporters move neurotransmitters into synaptic vesicles, regulating the concentrations of substances within them.
Learn more about material of blood here : brainly.com/question/25149738
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