Activity in this pathway decreases following dopamine loss, as can be shown by measuring preprotachykinin (PPT; the substance P precursor) mRNA and preproenkephalin B (PPEB; the dynorphin ...

Ouellette M and Brakier-Gingras L (1988) Increase in the relative abundance of preproenkephalin A messenger RNA in the ventricles of cardiomyopathic hamsters, Biochemical and Biophysical Research ...

Opioid receptors and their endogenous peptide ligands play important roles in the reward and reinforcement of drugs such as heroin, cocaine, and alcohol. The binding of dynorphins to the κ-opioid ...