Effect of tooth pulp stimulation on oxytocin and vasopressin release into the cerebrospinal fluid and fluid perfusing the cerebral ventricles in rats.
OBJECTIVE
Stress- and pain-related stimuli cause a release of vasopressin (AVP) and oxytocin (OT) into the cerebrospinal fluid (CSF) and extracellular fluid of the brain in various animal species. The aim of the study was to investigate the effect of stimulation of the nociceptive afferent terminals in the tooth pulp on the release of AVP and OT into CSF in rats under chloralose anesthesia.


METHODS
Cerebrospinal fluid was collected from the cerebellomedullary cistern and then 30-minute perfusions of the lateral cerebral ventricles with artificial cerebrospinal fluid (aCSF) were carried out. The perfusate was collected from the cerebellomedullary cistern at rest (control), during electric stimulation of the tooth pulp which induced nociceptive trigemino-hypoglossal reflex, and after stimulation. In the collected CSF and aCSF perfusates, AVP-like immunoreactivity (AVPLI) and OT-like immunoreactivity (OT-LI) were determined by radioimmunoassay (RIA).


RESULTS
The concentrations of AVP-LI and OT-LI in CSF were found to reach 21 pg/ml and 67 pg/ml, respectively. Electric tooth pulp stimulation exerted no effect on AVP and OT release into the fluid perfusing the cerebral ventricles during stimulation.


CONCLUSIONS
It was found that noxious stimulus from the tooth pulp is not a factor affecting significantly AVP and OT release into CSF.
Zubrzycka
M
M
Department of Experimental Physiology, Medical University, Lodz, Poland. ajanecka@zdn.am.lodz.pl
Janecka
A
A
D000818:Animals; D001127:Arginine Vasopressin / Q000134:cerebrospinal fluid*; D002552:Cerebral Ventricles / Q000502:physiology*; D003782:Dental Pulp / Q000502:physiology*; D004558:Electric Stimulation; D008297:Male; D010121:Oxytocin / Q000134:cerebrospinal fluid*; D010146:Pain / Q000503:physiopathology; D051381:Rats; D020318:Rats, Long-Evans
D001127:Arginine Vasopressin; D010121:Oxytocin