Progesterone but not estrogen depolarizes natural killer cells.
Natural killer (NK) cell tumoricidal and antimicrobial activities can be rapidly modulated by molecules that interact with membrane receptors. The discovery of NK cell depolarization induced by steroid-like Na+ channel agonists prompted a study of purified human NK cell excitability to a variety of steroids. Progesterone, but not estrogen, depolarized NK cells with concentration and time dependency. Excitability was measured by using flow cytometry and the anionic voltage-sensitive dye oxonol. Preincubation with the Na+ channel antagonist tetrodotoxin or removal of the extracellular Na+ blocked the response. Progesterone may rapidly change membrane potential, and eventually function, by acting on putative NK plasma membrane receptors coupled to Na+ conductances.
Department of Neurology, University of New Mexico School of Medicine, Albuquerque 87131.
R N
RN
Mandler
L C
LC
Seamer
M D
MD
Domalewski
A D
AD
Bankhurst
D000328:Adult; D001640:Bicuculline / Q000494:pharmacology; D004967:Estrogens / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D011374:Progesterone / Q000502:physiology*; D015222:Sodium Channels / Q000187:drug effects; D013256:Steroids / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D004967:Estrogens; D015222:Sodium Channels; D013256:Steroids; D013779:Tetrodotoxin; D011374:Progesterone; D001640:Bicuculline