Possible Interaction: Epinephrine and Substance P

“… substance P (35.… of epinephrine (+8.3 +/- 2.3 ng/min, P less than 0.01), arterial pressure (+11 +/- 5.3 mm Hg, P less than 0.…) by 1 min, and increased the plasma concentration of adrenocorticotropin (+26 +/- 10 pg/ml, P less than 0.01) by 3 min.”

“Intrathecally administered substance P (0.1-10 micrograms) produced a marked increase in tonic activity of the adrenal nerve in a dose-related manner.”

“These findings suggest the possibility that on the spinal level, substance P has an important role in the maintenance of tonic activity of the adrenal nerve and the transmission of nociceptive information to the adrenal nerve in rats.”

“The spontaneous adrenal nerve activity and both of the A- and C-sympathetic reflex components were proportionally reduced by intrathecal application of the SP antagonist (0.038-0.76 nmol), although the same doses did not affect A- and C-somatic reflex components.”

“The osmoregulatory effects of SP were accompanied by elevated plasma concentrations of norepinephrine and epinephrine.”

“Low iontophoretic currents (0-15 nA) of NA, adrenaline and the beta-agonist, clenbuterol, all strongly reduced responses to SP.”

“The stimulating action of acetylcholine on the superior cervical ganglion (as judged by the response of the nictitating membrane) was also potentiated by substance P. The responses of the nictitating membrane to adrenaline , noradrenaline and tyramine were potentiated by substance P as well.”