Effect of Cyclo-Oxygenase Inhibition on Renin, Catecholamine and Blood Pressure Responses to Haemorrhage and Captopril in Conscious Rabbits

1982 ◽  
Vol 63 (s8) ◽  
pp. 243s-246s
Author(s):  
M. S. Golub ◽  
M. E. Berger ◽  
N. D. Vlachakis ◽  
P. Eggena ◽  
M. P. Sambhi
Keyword(s):  
Blood Pressure ◽  
Drinking Water ◽  
Plasma Renin Activity ◽  
Blood Pressure Response ◽  
Plasma Renin ◽  
Pressure Response ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Conscious Rabbits ◽  
Noradrenaline And Adrenaline

1. Changes in plasma renin activity, plasma noradrenaline and adrenaline, and blood pressure were evaluated after mild haemorrhage (6 ml/kg) and subsequent intravenous captopril in conscious, restrained rabbits. Two protocols were followed. In the first, control animals (n = 8) were compared with rabbits receiving indomethacin (n = 8) in their drinking water for 5 days and intravenously during the haemorrhage and captopril study. In the second protocol, animals receiving propranolol in the drinking water and intravenously (n = 7) were compared with a group (n = 7) receiving propranolol plus indomethacin. 2. Urinary prostaglandin E excretion was decreased significantly with the oral administration of indomethacin in both protocols. Plasma renin activity levels were not significantly different at baseline, but the animals receiving indomethacin had significantly (P < 005) lower values after haemorrhage in both studies. The large increases in plasma renin activity after captopril were not influenced by indomethacin in either study. 3. The blood pressure response to captopril was significantly blunted in the indomethacin group in the first experiment. 4. Plasma noradrenaline and adrenaline levels were not affected by indomethacin treatment in either protocol. 5. It is concluded that the plasma renin activity response to haemorrhage in conscious rabbits is mediated in part by a cyclo-oxygenase-dependent component separable from the β-adrenoceptor. The renin response to converting enzyme inhibition is not influenced by cyclo-oxygenase inhibition. A component of the blood pressure response to captopril may involve a cyclo-oxygenase product.

Plasma Catecholamines and Plasma Renin Activity at Birth and during the First Days of Life

1980 ◽  
Vol 59 (s6) ◽  
pp. 319s-321s ◽  
Author(s):  
G. Leonetti ◽  
C. Bianchini ◽  
G. B. Picotti ◽  
A. Cesura ◽  
Letizia Caccamo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Umbilical Cord Blood ◽  
Plasma Catecholamines ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Plasma Adrenaline ◽  
Noradrenaline And Adrenaline ◽  
Noradrenaline Levels

1. Plasma noradrenaline and adrenaline concentrations and plasma renin activity were measured in 21 mothers at delivery and in their babies at birth (umbilical cord blood) and on days 1 and 5 of extrauterine life. 2. At birth plasma renin activity was significantly higher in the newborn than in mothers. Plasma renin activity increased further, but not significantly, on day 1 of life and significantly decreased on day 5. On day 5, 10 min head-up tilting caused no change in plasma renin activity. 3. Plasma noradrenaline in the newborn was higher than in mothers at birth and significantly decreased thereafter. Plasma adrenaline levels at birth were similar in the newborn and their mothers and significantly lower in the newborn in subsequent days. Tilting caused no increase in either plasma adrenaline or noradrenaline levels. 4. No correlation was found between plasma noradrenaline and adrenaline levels and plasma renin activity, or between noradrenaline, adrenaline or plasma renin activity and blood pressure.

Effects of opioid antagonism on the haemodynamic and hormonal responses to exercise

1988 ◽  
Vol 75 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Jan Staessen ◽  
Roberto Fiocchi ◽  
Roger Bouillon ◽  
Robert Fagard ◽  
Peter Hespel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Angiotensin Ii ◽  
Plasma Renin Activity ◽  
Serum Insulin ◽  
Plasma Renin ◽  
Endogenous Opioids ◽  
Renin Activity ◽  
Plasma Adrenaline ◽  
Noradrenaline And Adrenaline

1. Physical effort involves, along with an increase in the plasma concentration of β-endorphin, profound adaptations of the circulation and the endocrine system. The effects of opioid antagonism on the responses of blood pressure, heart rate and several hormones to exercise were therefore studied in 10 normal men. They exercised in the supine position up to 33% and 66% of their maximal exercise capacity and received in a randomized double-blind cross-over protocol, either saline or naloxone (10 mg intravenously, followed by a continuous infusion of 10 mg/h). 2. Intra-arterial pressure and heart rate were continuously monitored, but were not affected by naloxone. 3. At rest, opioid antagonism produced a rise in plasma renin activity and in plasma adrenocorticotropin, Cortisol and aldosterone, but only the stimulation of the two adrenocortical hormones differed significantly from the control experiments; at rest naloxone also prevented the fall in plasma adrenaline, which occurred with saline infusion. Furthermore, the exercise-induced rises in plasma angiotensin II, aldosterone, Cortisol, noradrenaline and adrenaline were higher on naloxone than on saline, while a similar tendency was also present for the increases with exercise in plasma renin activity and plasma adrenocorticotropin. Neither at rest nor during exercise did opioid antagonism alter plasma lactate and glucose and serum insulin and growth hormone. 4. In conclusion, (1) endogenous opioids are not involved in the responses of blood pressure and heart rate to supine exercise; (2) at rest and during exercise, the endogenous opioids inhibit the secretion of adrenocorticotropin, aldosterone, Cortisol, noradrenaline and adrenaline; (3) they also inhibit the plasma renin-angiotensin II system indirectly via the catecholamines.

Plasma Catecholamines and Renin Activity in Response to Exercise in Patients with Essential Hypertension

1975 ◽  
Vol 49 (5) ◽  
pp. 511-514
Author(s):  
J. Chodakowska ◽  
K. Nazar ◽  
B. Wocial ◽  
M. Jarecki ◽  
B. Skórka
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Plasma Catecholamines ◽  
Plasma Renin ◽  
Work Load ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Hypertensive Patients ◽  
Control Subjects

1. The effect of physical exercise on blood pressure, plasma catecholamines and plasma renin activity was studied in fourteen patients with essential hypertension and in eight healthy subjects. 2. Resting plasma noradrenaline and adrenaline and plasma renin activity of the hypertensive patients did not differ from those of the control subjects. 3. In response to graded exercise producing successive heart rates of 120, 140 and 160 beats/min, significantly greater increases of blood pressure were found in the patients than in the control subjects. 4. Plasma noradrenaline increased significantly in both groups at all levels of exercise, the responses being significantly greater in the hypertensive patients. 5. The mean arterial blood pressure was significantly correlated with plasma noradrenaline concentration in the control subjects but not in the hypertensive patients. 6. In the hypertensive group plasma adrenaline increased significantly after exercise at all work loads whereas, in the control group, significant increase occurred only at the highest work load. The differences in the response of the two groups were significant at each work load. 7. Plasma renin activity increased significantly after exercise at the heart rate of 120 beats/min, both in the hypertensive patients and in the control subjects. The magnitude of the response was similar in the two groups.

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