Increase in cardiodepressant factor release from the posterior pituitary lobe after angiotensin II infusion into the internal carotid artery.
In our previous research the presence of a cardiodepressant factor in the medium incubating the posterior pituitary lobe 'in situ' has been demonstrated. This study presents experiments demonstrating cardiodepressant activity in medium incubating the posterior pituitary lobe 'in situ' and in dialysates of venous blood from the sella turcica region before and during angiotensin II (ANG II) infusion into the internal carotid artery in rat. Cardiodepressant activity was determined on spontaneously discharging isolated auricle of the right atrium in a two-day-old rat. It has been demonstrated that medium incubating the posterior pituitary lobe which was collected during angiotensin II infusion caused a greater decrease in auricle discharge rate than medium collected before the infusion. Angiotensin II infusion into the internal carotid artery caused a dose-dependent increase in cardiodepressant activity in dialysates of blood outflowing from the sella turcica region. The present results indicate that angiotensin II increase the release of cardiodepressant factor from the posterior pituitary lobe into blood in a dose-dependent manner.
Goraca
A
A
Department of Physiology, Medical University of Lodz, Poland.
Traczyk
W Z
WZ
D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002339:Carotid Arteries; D004305:Dose-Response Relationship, Drug; D005260:Female; D007261:Infusions, Intra-Arterial; D008297:Male; D017551:Microdialysis; D009201:Myocardial Depressant Factor / Q000378:metabolism*; D010904:Pituitary Gland, Posterior / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012658:Sella Turcica / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*
D009201:Myocardial Depressant Factor; D014662:Vasoconstrictor Agents; D000804:Angiotensin II