L-propionylcarnitine increases postischemic blood flow but does not affect recovery of energy charge

1991 ◽  
Vol 261 (1) ◽  
pp. H172-H180 ◽  
Author(s):  
L. M. Sassen ◽  
K. Bezstarosti ◽  
W. J. Van der Giessen ◽  
J. M. Lamers ◽  
P. D. Verdouw
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Systemic Vascular Resistance ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Contractile Function ◽  
Energy Charge ◽  
Left Ventricular ◽  
Arterial Blood

Effects of pretreatment with L-propionylcarnitine (50 mg/kg, n = 9) or saline (n = 10) were studied in open-chest anesthetized pigs, in which ischemia was induced by decreasing left anterior descending coronary artery blood flow to 20% of baseline. After 60 min of ischemia, myocardium was reperfused for 2 h. In both groups, flow reduction abolished contractile function of the affected myocardium and caused similar decreases in ATP (by 55%) and energy charge [(ATP + 0.5ADP)/(ATP + ADP + AMP); decrease from 0.91 to 0.60], mean arterial blood pressure (by 10-24%), the maximum rate of rise in left ventricular pressure (by 26-32%), and cardiac output (by 20-30%). During reperfusion, “no-reflow” was attenuated by L-propionylcarnitine, because myocardial blood flow returned to 61 and 82% of baseline in the saline- and L-propionylcarnitine-treated animals, respectively. Cardiac output of the saline-treated animals further decreased (to 52% of baseline), and systemic vascular resistance increased from 46 +/- 3 to 61 +/- 9 mmHg.min.l-1, thereby maintaining arterial blood pressure. In L-propionylcarnitine-treated pigs, cardiac output remained at 75% of baseline, and systemic vascular resistance decreased from 42 +/- 3 to 38 +/- 4 mmHg.min.l-1. In both groups, energy charge but not the ATP level of the ischemic-reperfused myocardium tended to recover, whereas the creatine phosphate level showed significantly more recovery in saline-treated animals. We conclude that L-propionylcarnitine partially preserved vascular patency in ischemic-reperfused porcine myocardium but had no immediate effect on “myocardial stunning.” Potential markers for long-term recovery were not affected by L-propionylcarnitine.

Sympathoadrenal-circulatory regulation of arterial pressure during orthostatic stress in young and older men

1992 ◽  
Vol 263 (5) ◽  
pp. R1147-R1155 ◽  
Author(s):  
J. A. Taylor ◽  
G. A. Hand ◽  
D. G. Johnson ◽  
D. R. Seals
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Systemic Vascular Resistance ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Older Men ◽  
Orthostatic Stress ◽  
Plasma Norepinephrine ◽  
Lower Body ◽  
Arterial Blood

Our purpose was to test the hypothesis that human aging alters sympathoadrenal-circulatory control of arterial blood pressure during orthostasis. Plasma catecholamine and hemodynamic adjustments to two different forms of orthostatic stress, lower body suction (-10 to -50 mmHg) and standing, were determined in 14 young (26 +/- 1 yr) and 13 older (64 +/- 1) healthy, normally active men. During quiet supine rest, cardiac output tended to be lower and systemic vascular resistance higher in the older men, but no other differences were observed. On average, arterial blood pressure was well maintained during both forms of orthostasis in the two groups; the older men actually demonstrated better maintenance of pressure (P < 0.05) and a lesser incidence of orthostatic hypotension than the young men during lower body suction. Despite a blunted reflex tachycardia during orthostatic stress (P < 0.05), cardiac output tended to decrease less in the older men because of a smaller decline in stroke volume (P < 0.05, suction only), whereas the reflex increases in systemic vascular resistance were not different in the two groups. The whole forearm vasoconstrictor response tended to be attenuated in the older men during lower body suction, but was identical in the two groups with standing. Forearm skin vascular resistance was unaltered during lower body suction in both groups. Orthostasis-evoked increases in antecubital venous plasma norepinephrine concentrations were similar in the young and older men, whereas little or no increases in plasma epinephrine concentrations were observed in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Circulatory responses to hypocapnia in the anesthetized dog

1965 ◽  
Vol 208 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Hermes A. Kontos ◽  
H. Page Mauck ◽  
David W. Richardson ◽  
John L. Patterson
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Systemic Vascular Resistance ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Positive Pressure ◽  
Arterial Blood ◽  
Vasoconstrictor Effect ◽  
Anesthetized Dogs ◽  
Intact Limb

The circulatory responses to hypocapnia were studied in 40 anesthetized dogs. Hypocapnia induced without a change in ventilation caused slight increase in limb vascular resistance in six dogs and decrease in one. Hypocapnia induced by hyperventilation caused increase in limb vascular resistance in six dogs and decrease in four. Following administration of phenoxybenzamine into the femoral artery, hypocapnia induced by either method invariably caused increase in limb vascular resistance (8 dogs). These results show that hypocapnia has a direct vasoconstrictor effect on limb blood vessels. In the intact limb this response may be opposed by vasodilator effects mediated through nerves. Hypocapnia induced without change in ventilation had no significant effect on cardiac output, systemic vascular resistance or arterial blood pressure (8 dogs). Hypocapnia induced by increased ventilation was associated with significant decreases in cardiac output and systemic arterial blood pressure and significant increase in systemic vascular resistance (9 dogs). These responses were probably related to the effects of increased intermittent positive pressure used to augment ventilation.

Renal and iliac vascular responses to left ventricular receptor stimulation in conscious dogs

1984 ◽  
Vol 246 (5) ◽  
pp. R788-R798
Author(s):  
A. J. Gorman ◽  
K. G. Cornish ◽  
I. H. Zucker
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Neural Control ◽  
Cholinergic Receptor ◽  
Left Ventricular ◽  
Conscious Dog ◽  
Arterial Blood

The purpose of the present study was to investigate the relative responses of the renal and iliac vascular beds to the selective chemical stimulation of left ventricular receptors in the conscious dog. Twenty dogs were chronically instrumented to obtain measurements of arterial blood pressure, renal blood flow, and iliac blood flow before and after a bolus intracoronary injection of veratridine (0.4-1.0 micrograms/kg in 0.5-ml vol) with the heart paced. The responses to intracoronary veratridine were a significant reduction in arterial blood pressure averaging 25 mmHg accompanied by a simultaneous reduction in renal blood flow of 25%. Renal resistance did not change throughout the course of the response analyzed (50 s). Iliac blood flow, however, increased, reaching a peak of 35% above control due to a 51% decrease in iliac resistance. After sinoaortic denervation, renal resistance still failed to show a decrease, although the recovery of arterial blood pressure and iliac resistance was prolonged. After a mild hypotensive hemorrhage (20 ml/kg), a greater decrease in iliac resistance occurred with intracoronary veratridine injections, but renal resistance still did not change. The reduction in iliac resistance with intracoronary veratridine was significantly attenuated after phentolamine administration (2 mg/kg iv) but not after atropine alone (0.2 mg/kg iv). A significant cholinergic receptor component of iliac vasodilation was observed only after prior alpha-adrenergic-receptor blockade. The results of this study are consistent with the conclusion that in the conscious dog, left ventricular receptors exert a preferential neural control over skeletal muscle vascular resistance and do not influence renal vascular resistance.

Central and regional hemodynamic effects during infusion of Big endothelin-1 in healthy humans

1996 ◽  
Vol 80 (6) ◽  
pp. 1921-1927 ◽  
Author(s):  
G. Ahlborg ◽  
A. Ottosson-Seeberger ◽  
A. Hemsen ◽  
J. M. Lundberg
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Systemic Vascular Resistance ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Mean Arterial Blood Pressure ◽  
Endothelin 1 ◽  
Healthy Humans ◽  
Arterial Blood

Big endothelin-1 (Big ET-1) was given intravenously to six healthy men to study uptakes and vascular effects. Blood samples were taken from systemic and pulmonary arterial and internal jugular and deep forearm venous catheters. Arterial Big ET-1-like immunoreactivity (Big ET-1-LI) increased from 5.43 +/- 0.60 to 756 +/- 27 pmol/l, and ET-1-LI increased from 4.67 +/- 0.08 to 6.67 +/- 0.52 pmol/l (P < 0.001). Skeletal muscle fractional extraction of Big ET-1-LI was 15 +/- 4%. ET-1-LI release did not increase in the studied vascular beds. Heart rate fell by 17% (P < 0.001), cardiac output fell by 26% (P < 0.001), and stroke volume fell by 11% (P < 0.05). Mean arterial blood pressure increased 18%, systemic vascular resistance increased 65%, and pulmonary vascular resistance increased 57% (P < 0.01-0.001). Pulmonary blood pressures, forearm blood flow, arterial pH, arterial PCO2, and systemic arterial-internal jugular venous O2 difference remained unchanged. No specific Big ET-1 receptors were found in human pulmonary membranes. The half-maximal inhibitory concentration for the receptor antagonist bosentan was 181 nM. In summary, circulating Big ET-1 elicits greater increases in mean arterial blood pressure and systemic vascular resistance and decreases in heart rate and cardiac output compared with an equimolar ET-1 infusion (26).

Forearm and finger blood flow responses to passive body tilts

1979 ◽  
Vol 46 (2) ◽  
pp. 288-292 ◽  
Author(s):  
Y. A. Mengesha ◽  
G. H. Bell
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Pulse Rate ◽  
Forearm Blood Flow ◽  
Body Tilt ◽  
Finger Blood Flow ◽  
Arterial Blood ◽  
Forearm Vascular Resistance

Ten to fifteen healthy subjects, ages 18--30 yr, were used to assess the correlation of forearm blood flow with graded passive body tilts and vascular resistance and also to discern the relative effects of body tilts on finger blood flow. In the head-up tilts forearm blood flow and arterial blood pressure fell progressively, whereas forearm vascular resistance and pulse rate increased. In the head-down tilts the forearm blood flow and the arterial blood pressure increased, whereas the forearm vascular resistance and pulse rate decreased. These changes were found to be significantly correlated with the different tilt angles and with one another. In a preliminary study it was found that infrared heating of the carpometacarpal region produced finger vasodilatation similar to the forearm vasodilatation observed by Crockford and Hellon (6). However, unlike forearm blood flow, finger blood flow showed no appreciable response to either the head-up or head-down tilts. This indicates that the sympathetic tone and the volume of blood in the finger are not appreciably altered by this test procedure at least 1 min after the body tilt is assumed.

Effects of isoproterenol on the cardiovascular system of fetal sheep exposed to long-term high-altitude hypoxemia

1995 ◽  
Vol 78 (5) ◽  
pp. 1793-1799 ◽  
Author(s):  
M. Kamitomo ◽  
T. Ohtsuka ◽  
R. D. Gilbert
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Right Ventricular ◽  
High Altitude ◽  
Arterial Blood Pressure ◽  
Left Ventricular ◽  
Arterial Blood ◽  
Isoproterenol Infusion

We exposed fetuses to high-altitude (3,820 m) hypoxemia from 30 to 130 days gestation, when we measured fetal heart rate, right and left ventricular outputs with electromagnetic flow probes, and arterial blood pressure during an isoproterenol dose-response infusion. We also measured the distribution of cardiac output with radiolabeled microspheres during the maximal isoproterenol dose. Baseline fetal arterial blood pressure was higher in long-term hypoxemic fetuses (50.1 +/- 1.3 vs. 43.4 +/- 1.0 mmHg) but fell during the isoproterenol infusion to 41.3 +/- 1.4 and 37.5 +/- 1.4 mmHg, respectively, at the highest dose. Heart rate was the same in both groups and did not differ during isoproterenol infusion. Baseline fetal cardiac output was lower in the hypoxemic group (339 +/- 18 vs. 436 +/- 19 ml.min-1.kg-1) due mainly to a reduction in right ventricular output. During the isoproterenol infusion, right ventricular output increased to the same extent in both hypoxemic and normoxic fetuses (approximately 35%); however, left ventricular output increased only approximately 15% in the hypoxemic group compared with approximately 40% in the normoxic group. The percent change in individual organ blood flows during isoproterenol infusion in the hypoxemic groups was not significantly different from the normoxic group. All of the mechanisms that might be responsible for the differential response of the fetal left and right ventricles to long-term hypoxia are not understood and need further exploration.

Patterned cardiovascular responses to sleep and nonrespiratory arousals in a porcine model

1998 ◽  
Vol 85 (4) ◽  
pp. 1285-1291 ◽  
Author(s):  
Sandrine H. Launois ◽  
Joseph H. Abraham ◽  
J. Woodrow Weiss ◽  
Debra A. Kirby
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Eye Movement ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Mean Arterial Blood Pressure ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Arterial Blood

Patients with obstructive sleep apnea experience marked cardiovascular changes with apnea termination. Based on this observation, we hypothesized that sudden sleep disruption is accompanied by a specific, patterned hemodynamic response, similar to the cardiovascular defense reaction. To test this hypothesis, we recorded mean arterial blood pressure, heart rate, iliac blood flow and vascular resistance, and renal blood flow and vascular resistance in five pigs instrumented with chronic sleep electrodes. Cardiovascular parameters were recorded during quiet wakefulness, during non-rapid-eye-movement and rapid-eye-movement sleep, and during spontaneous and induced arousals. Iliac vasodilation (iliac vascular resistance decreased by −29.6 ± 4.1% of baseline) associated with renal vasoconstriction (renal vascular resistance increased by 10.3 ± 4.0%), tachycardia (heart rate increase: +23.8 ± 3.1%), and minimal changes in mean arterial blood pressure were the most common pattern of arousal response, but other hemodynamic patterns were observed. Similar findings were obtained in rapid-eye-movement sleep and for acoustic and tactile arousals. In conclusion, spontaneous and induced arousals from sleep may be associated with simultaneous visceral vasoconstriction and hindlimb vasodilation, but the response is variable.

Rapid effects of parathyroid hormone(1–34) and prostaglandin E2 on bone blood flow and strontium clearance in the rat in vivo

1991 ◽  
Vol 131 (3) ◽  
pp. 359-365 ◽  
Author(s):  
E. Cochrane ◽  
I. D. McCarthy
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Parathyroid Hormone ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Prostaglandin E ◽  
Bone Blood Flow ◽  
Vascular Effects ◽  
Arterial Blood ◽  
Mineral Ions

ABSTRACT The vascular effects of noradrenaline, ATP, parathyroid hormone (PTH) and prostaglandin E2 (PGE2) were investigated in the rat. Additionally, the exchange of mineral ions between bone and blood was assessed by measuring strontium clearance, with the aim of investigating whether the vascular effects of these agents altered uptake of mineral ions or if this exchange could be changed independently of blood flow. Radioactive microspheres and 85Sr were used to establish bone blood flow and mineral clearance. Measurements of bone blood flow and arterial pressure were made in each animal and used to calculate vascular resistance. A measurement of 85Sr clearance was also obtained. Arterial blood pressure was significantly affected by noradrenaline (P ≤ 0·003) and ATP (P ≤ 0·015). Additionally, noradrenaline significantly (P ≤ 0·03) reduced bone blood flow. This decrease was related to a significant increase in vascular resistance. Arterial blood pressure and bone blood flow were significantly reduced by both bovine PTH(1–34) (P ≤ 0·001, P ≤ 0·02) and PGE2 (P ≤ 0·005, P ≤ 0·001). Vascular resistance to bone was increased by both agents but this was only statistically significant in the case of PGE2 (P ≤ 0·01). A significant (P ≤ 0·001) reduction in strontium was also produced by PGE2. In each group the relationship between bone blood flow and strontium clearance was then analysed. Only the PGE2-treated group had a slope of the regression which was statistically different from both the control animals and the other drug-treated groups. Treatment with PGE2 therefore resulted in a dose-related decrease in 85Sr clearance which was not related to the reduction in bone blood flow. Journal of Endocrinology (1991) 131, 359–365

Validity of fluorescent microspheres method for bone blood flow measurement during intentional arterial hypotension

2003 ◽  
Vol 95 (3) ◽  
pp. 1153-1158 ◽  
Author(s):  
H. Anetzberger ◽  
E. Thein ◽  
M. Becker ◽  
A. K. Walli ◽  
K. Messmer
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Arterial Blood Pressure ◽  
Left Ventricular ◽  
Bone Blood Flow ◽  
Control Mechanisms ◽  
Arterial Blood ◽  
Severe Hypotension ◽  
New Zealand White Rabbits ◽  
Blood Pressures

In this study, we compared bone blood flow values obtained by simultaneously injected fluorescent (FM) and radiolabeled microspheres (RM) at stepwise reduced arterial blood pressure. Ten anesthetized female New Zealand White rabbits received simultaneous left ventricular injections of FM and RM at 90, 70, and 50 mmHg mean arterial blood pressure (MAP). After the experiments, both kidneys and long bones of all four limbs were removed and dissected in a standardized manner. Radioactivity (corrected for decay, background, and spillover) and fluorescence were determined, and blood flow values were calculated. Relative blood flow values estimated for each bone sample by RM and FM were significantly correlated ( r = 0.98, slope = 0.99, and intercept = 0.04 for 90 mmHg; r = 0.98, slope = 0.94, and intercept = 0.09 for 70 mmHg; r = 0.98, slope = 0.96, and intercept = 0.07 for 50 mmHg). Blood flow values (ml · min-1 · 100 g-1) of right and left bone samples determined at the different arterial blood pressures were identical. During moderate hypotension (70 mmHg MAP), blood flow in all bone samples remained unchanged compared with 90 mmHg MAP, whereas a significant decrease of bone blood flow was observed at severe hypotension (50 mmHg MAP). Our results demonstrate that the FM technique is valid for measuring bone blood flow. Differences in bone blood flow during altered hemodynamic conditions can be detected reliably. In addition, changes in bone blood flow during hypotension indicate that vasomotor control mechanisms, as well as cardiac output, play a role in setting bone blood flow.

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