Oxytocin content in the venous blood outflowing from the vicinity of the cavernous sinus and from the femoral vein.
OBJECTIVE
Magnocellular neuroendocrine cells of the supraoptic nucleus of the hypothalamus produce and release the hormones vasopressin and oxytocin in response to a variety of stimuli to regulate body water and salt as well as and parturition and lactation. The aim of the present study was to estimate oxytocin release into the blood dialysate outflowing from the vicinity of the cavernous sinus and from the femoral vein after NMDA (N-methyl-D-aspartic acid) infusion or acute hypoxia.


METHODS
The samples of dialysates of venous blood outflowing from the vicinity of the cavernous sinus and, for comparison, from the femoral vein were collected in anesthetized rats. Oxytocin was determined in the sample of dialysates by radioimmunoassay.


RESULTS
NMDA acid infusion or acute hypoxia caused an increase of oxytocin concentration in the blood dialysate outflowing from the vicinity of the cavernous sinus of the sella turcica and from the femoral vein. A blockade of the NMDA receptors by specific and non-specific antagonists significantly inhibited the increase in the blood dialysate oxytocin concentration.


CONCLUSIONS
The results indicate the involvement of excitatory amino acid or acute hypoxia in the control of oxytocin release into the blood.
Goraca
Anna
A
Department of Experimental and Clinical Physiology, Institute of Physiology and Biochemistry, Medical University of Lodz, Poland. agoraca@zdn.am.lodz.pl
D000818:Animals; D002426:Cavernous Sinus; D005268:Femoral Vein; D000860:Hypoxia / Q000097:blood; D008297:Male; D016202:N-Methylaspartate / Q000008:administration & dosage; D010121:Oxytocin / Q000097:blood* / Q000378:metabolism; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors
D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D010121:Oxytocin; C056723:FG 9041; D016202:N-Methylaspartate