What is found in high concentrations in the bloodstream in a vertebrate?

The likely substance to be found in high concentrations in the blood stream of a vertebrate is water, it is considered to be polar and the water is made up of blood and this is usually the substance that made up or a component that a living thing has such as humans.

not always but somethings can be reproduced in a laboratory.

loss of sensation to pressure and touch

the dorsal column–medial lemniscus pathway (dcml) (also known as the posterior column-medial lemniscus pathway (pcml)) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception (position) from the skin and joints.