TY - JOUR
T1 - The effect of distension of the uterus on plasma renin activity (PRA) in anaesthetized pigs
AU - Vacca, Giovanni
AU - Battaglia, Antonio
AU - Ferro, Roberto
AU - Grossini, Elena
AU - Mary, David A.S.G.
AU - Molinari, Claudio
AU - Surico, Nicola
PY - 1998/11/10
Y1 - 1998/11/10
N2 - It has recently been shown that distension of the uterus in anaesthetized pigs causes reflex haemodynamic responses through efferent sympathetic mechanisms. The present study was undertaken to determine whether these mechanisms include activation of the renin-angiotensin system. The same methods were used in 14 pigs which were anaesthetized with α-chloralose and artificially ventilated. Balloons positioned within the uterus were distended for periods of 30 min by injecting 20 ml of warm Ringer solution. The responses of arterial blood pressure and heart rate were respectively prevented by blockade of α-adrenergic receptors with phentolamine and atrial pacing. Changes in plasma renin activity (PRA) were assessed during the last minute of distension by radioimmunoassay of angiotensin I. In each of 10 pigs, distension of the uterus (mean uterine transmural pressure of 17 mmHg) caused an increase in PRA in the absence of changes of interfering haemodynamic variables. In the remaining four pigs, this response was graded by step increments of the distension. The increase in PRA caused by uterine distension was abolished by bilateral section of the renal nerves (five pigs) or by blockade of β-adrenergic receptors with propranolol. The present study showed that distension of the uterus in anaesthetized pigs primarily caused a reflex increase in PRA. This reflex response was mediated by renal nerves and involved β-adrenergic receptors. Copyright (C) 1998 Elsevier Science B.V.
AB - It has recently been shown that distension of the uterus in anaesthetized pigs causes reflex haemodynamic responses through efferent sympathetic mechanisms. The present study was undertaken to determine whether these mechanisms include activation of the renin-angiotensin system. The same methods were used in 14 pigs which were anaesthetized with α-chloralose and artificially ventilated. Balloons positioned within the uterus were distended for periods of 30 min by injecting 20 ml of warm Ringer solution. The responses of arterial blood pressure and heart rate were respectively prevented by blockade of α-adrenergic receptors with phentolamine and atrial pacing. Changes in plasma renin activity (PRA) were assessed during the last minute of distension by radioimmunoassay of angiotensin I. In each of 10 pigs, distension of the uterus (mean uterine transmural pressure of 17 mmHg) caused an increase in PRA in the absence of changes of interfering haemodynamic variables. In the remaining four pigs, this response was graded by step increments of the distension. The increase in PRA caused by uterine distension was abolished by bilateral section of the renal nerves (five pigs) or by blockade of β-adrenergic receptors with propranolol. The present study showed that distension of the uterus in anaesthetized pigs primarily caused a reflex increase in PRA. This reflex response was mediated by renal nerves and involved β-adrenergic receptors. Copyright (C) 1998 Elsevier Science B.V.
KW - Plasma renin activity
KW - Sympathetic efferents
KW - Uterus distension
UR - http://www.scopus.com/inward/record.url?scp=0031792189&partnerID=8YFLogxK
U2 - 10.1016/S0165-1838(98)00136-2
DO - 10.1016/S0165-1838(98)00136-2
M3 - Article
SN - 0165-1838
VL - 73
SP - 163
EP - 169
JO - Journal of the Autonomic Nervous System
JF - Journal of the Autonomic Nervous System
IS - 2-3
ER -