Document Detail

Reversal of peripheral nerve injury-induced hypersensitivity in the postpartum period: role of spinal oxytocin.
MedLine Citation:
PMID:  23249932     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Physical injury, including surgery, can result in chronic pain; yet chronic pain following childbirth, including cesarean delivery in women, is rare. The mechanisms involved in this protection by pregnancy or delivery have not been explored.
METHODS: We examined the effect of pregnancy and delivery on hypersensitivity to mechanical stimuli of the rat hindpaw induced by peripheral nerve injury (spinal nerve ligation) and after intrathecal oxytocin, atosiban, and naloxone. Additionally, oxytocin concentration in lumbar spinal cerebrospinal fluid was determined.
RESULTS: Spinal nerve ligation performed at mid-pregnancy resulted in similar hypersensitivity to nonpregnant controls, but hypersensitivity partially resolved beginning after delivery. Removal of pups after delivery prevented this partial resolution. Cerebrospinal fluid concentrations of oxytocin were greater in normal postpartum rats prior to weaning. To examine the effect of injury at the time of delivery rather than during pregnancy, spinal nerve ligation was performed within 24 h of delivery. This resulted in acute hypersensitivity that partially resolved over the next 2-3 weeks. Weaning of pups resulted only in a temporary return of hypersensitivity. Intrathecal oxytocin effectively reversed the hypersensitivity following separation of the pups. Postpartum resolution of hypersensitivity was transiently abolished by intrathecal injection of the oxytocin receptor antagonist, atosiban.
CONCLUSIONS: These results suggest that the postpartum period rather than pregnancy protects against chronic hypersensitivity from peripheral nerve injury and that this protection may reflect sustained oxytocin signaling in the central nervous system during this period.
Silvia Gutierrez; Baogang Liu; Ken-ichiro Hayashida; Timothy T Houle; James C Eisenach
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Anesthesiology     Volume:  118     ISSN:  1528-1175     ISO Abbreviation:  Anesthesiology     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2012-12-19     Completed Date:  2013-02-25     Revised Date:  2014-01-10    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  152-9     Citation Subset:  AIM; IM    
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MeSH Terms
Behavior, Animal / drug effects
Disease Models, Animal
Hormone Antagonists / administration & dosage
Hypersensitivity / cerebrospinal fluid,  etiology*,  prevention & control*
Injections, Spinal
Naloxone / administration & dosage
Narcotic Antagonists / administration & dosage
Oxytocics / cerebrospinal fluid,  pharmacology*
Oxytocin / cerebrospinal fluid,  pharmacology*
Peripheral Nerve Injuries / cerebrospinal fluid,  complications*
Physical Stimulation
Postpartum Period
Rats, Sprague-Dawley
Spinal Nerves / drug effects
Vasotocin / administration & dosage,  analogs & derivatives
Grant Support
Reg. No./Substance:
0/Hormone Antagonists; 0/Narcotic Antagonists; 0/Oxytocics; 36B82AMQ7N/Naloxone; 50-56-6/Oxytocin; 90779-69-4/atosiban; W6S6URY8OF/Vasotocin
Comment In:
Anesthesiology. 2013 Jan;118(1):16-8   [PMID:  23249926 ]

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