Neuro-endocrine interaction on lymphocytes. Testosterone-induced modulation of the lymphocyte substance P receptor.
Human IM-9 B-lymphoblasts have been shown to express the receptor for the neuropeptide substance P (SP). The present study was undertaken to evaluate the effect of sex hormones on this receptor. Testosterone inhibited [125I]SP binding in a dose-dependent manner with an IC50 of approximately 100 nM, while both estradiol and progesterone failed to inhibit SP binding even at concentrations as high as 1 microM. Furthermore, Scatchard analysis indicated that the dissociation constant (Kd) of the SP receptor was markedly increased from 0.25 nM to 2.2 nM when cells were incubated with testosterone. These data indicate a unique neuro-endocrine interaction on lymphocytes involving the substance P receptor.
Parnet
P
P
Howard Hughes Medical Institute Laboratories, Department of Medicine, University of California, San Francisco.
Payan
D G
DG
Kerdelhué
B
B
Mitsuhashi
M
M
D004305:Dose-Response Relationship, Drug; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism / Q000502:physiology*; D009490:Neurosecretory Systems / Q000502:physiology*; D009994:Osmolar Concentration; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology*
D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D013373:Substance P; D013739:Testosterone