Lactation abolishes corticotropin-releasing factor-induced oxytocin secretion in the conscious rat.
We have assessed the response of plasma oxytocin (OT) to intracerebroventricular CRF-41 in both virgin female and lactating rats. In virgin rats CRF-41 resulted in an increase in plasma OT from 5-30 min after administration. In lactating rats, however, there was a complete abolition of the OT response, even at the highest dose of CRF-41. These data demonstrate another feature of the hormone nonresponsiveness apparent during lactation and suggests that one of the reasons for the lack of stress responses could be a down-regulation of the response to endogenously released CRF-41.
Patel
H
H
Neuroendocrinology Unit, Charing Cross and Westminster Medical School, Charing Cross Hospital, London, United Kingdom.
Chowdrey
H S
HS
Lightman
S L
SL
D000818:Animals; D003243:Consciousness; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007276:Injections, Intraventricular; D007774:Lactation / Q000502:physiology*; D009994:Osmolar Concentration; D010121:Oxytocin / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D010121:Oxytocin; D003346:Corticotropin-Releasing Hormone