CATECHOLAMINES IN HUMAN DENTAL-PULP - A COMBINED IMMUNOHISTOCHEMICAL AND CHROMATOGRAPHIC STUDY

Pharmacological studies have suggested that nerve-released catecholami nes may play an important role in the regulation of vascular tone and in the modulation of sensory nerve activity in animal teeth. We have u sed tyrosine hydroxylase-immunohistochemistry to detect catecholamine- producing cells in human dental pulp and high performance liquid chrom atography to identify and quantitate catecholamines in this tissue. Ty rosine hydroxylase-immunoreactivity was confined to a sub-population o f nerve fibres that were mainly localized around blood vessels. Consid erable concentrations of norepinephrine (17.8 +/- 3.75 pg/mg tissue) a nd much lower concentrations of dopamine and epinephrine (0.27 +/- 0.1 0 and 0.19 +/- 0.11 pg/mg, respectively) were measured in all samples examined. It is suggested that catecholamines in human dental pulp are exclusively contained in nervous structures that are mainly associate d with blood vessels and that norepinephrine is the candidate neurotra nsmitter of these nerve fibres. These data provide the basis to furthe r studies addressed to clarify the possible functions of catecholamine s in human dental pulp during physiological as well as inflammatory si tuations.