Possible Interaction: Substance P and Adrenocorticotropic Hormone

“ Substance P decreased the plasma levels of ACTH and corticosterone but did not increase the median eminence content of vasopressin.”

“ Substance P (0.07 mg/100 g body wt) decreased ACTH plasma levels and raised corticosterone release from steroidogenic tissue, that showed clear signs of stimulation.”

“However, the possibility remains to be explored that SP may play a role in quenching, via a receptor-independent mechanism, the exceedingly high glucocorticoid responses to ACTH of rat adrenocortical cells.”

“These results demonstrate for the first time that SP exerts opposite effects upon the release of ACTH and AVP in the same animal, and suggest that these actions occur at the level of the hypothalamus.”

“… substance P (35.6 pmol) into the superficial layers (lamina I-II) of subnucleus caudalis increased the adrenal secretion of epinephrine (+8.3 +/- 2.3 …), and heart rate (+19.4 +/- 4.9 beats/min, P less than 0.01) by 1 min, and increased the plasma concentration of adrenocorticotropin (+….”

“In summary, these studies demonstrate that the chronic administration of ACTH or corticosterone significantly decreases the quantity of peripherally transported SP in the sensory vagus nerve and, presumably, synthesis within the vagal sensory ganglia.”

“Degradation of substance P is strongly inhibited by neurotensin, somatostatin, ACTH 1-39, and less effectively by LHRH but not by Leucine-enkephalin.”

“The results suggest that although SRIF and SP are able to modulate the release of ACTH from the anterior pituitary gland, they do so only at a high concentration.(ABSTRACT TRUNCATED AT 250 WORDS)”