Effects of unilateral ovariectomy with compensatory hypertrophy on ovarian blood flow, oxygen consumption and progestin secretion in the 16-day pregnant rat

1999 ◽  
Vol 11 (3) ◽  
pp. 153 ◽  
Author(s):  
N. W. Bruce ◽  
H. M. Massa
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Tissue Blood Flow ◽  
Corpora Lutea ◽  
Tissue Mass ◽  
Pregnant Rat ◽  
Unilateral Ovariectomy ◽  
Arterial Blood ◽  
Progesterone Secretion ◽  
Luteal Tissue

Stimulated ovulation with resultant multiple corpora lutea (CL) can result in lower proges-terone levels than expected from the increased luteal tissue mass. Unilateral ovariectomy (ULO) was used to increase CL number in rats and determine whether this would compromise luteal tissue blood flow, oxygen consumption and progestin secretion. All investigations were performed in vivo, using a venous outflow technique on Day 16 of gestation, when progesterone secretion is maximal. ULO, performed before pregnancy, doubled CL number and total CL mass in the remaining ovary of six treated compared to five control rats. Growth of CL was not affected. The rate of ovarian blood flow (µL min−1 mg CL−1) fell to 47% of control levels in ULO animals and progesterone secretion (µg h−1 mg CL−1) to 68%. Secretion of the minor progestin, 20α-hydroxypregn-4-en-one was not affected. Tissue oxygen consumption was maintained despite the reduction in blood flow by an increase in oxygen extraction from arterial blood. These results suggest that overcrowding of CL in ULO-stimulated rat ovaries compromises luteal tissue blood flow and subsequently progesterone secretion.

EFFECTS OF OESTRADIOL ON STEROID DEHYDROGENASE ACTIVITIES IN RAT CORPORA LUTEA

1980 ◽  
Vol 84 (3) ◽  
pp. 391-395 ◽  
Author(s):  
R. G. RODWAY ◽  
I. ROTHCHILD
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Corpora Lutea ◽  
Pregnant Rat ◽  
Oestradiol Treatment ◽  
Rapid Induction ◽  
Progesterone Secretion ◽  
Luteal Tissue ◽  
Steroid Dehydrogenase

The activities of 20α-hydroxysteroid dehydrogenase and 3β-hydroxysteroid dehydrogenase in rat corpora lutea during the second half of pregnancy were measured. In luteal tissue of the intact pregnant rat, 20α-hydroxysteroid dehydrogenase activity was undetectable between days 12 and 18 of pregnancy but appeared slowly after hypophysectomy and hysterectomy on day 12. Treatment of the hypophysectomized and hysterectomized animal with oestradiol delayed this increase until day 17, at which time a rapid induction of this enzyme occurred. In the normal pregnant rat mean luteal 3β-hydroxysteriod dehydrogenase activity increased between days 12 and 18 (P <0·05, Student's t-test) but fell rapidly after hypophysectomy and hysterectomy on day 12. Oestradiol treatment prevented this fall in activity and enzyme activity was not distinguishable from that of the intact rat. Progesterone secretion correlated well with the activities of these two enzymes in the three conditions examined.

Relationship of luteal blood flow and corpus luteum function in pseudopregnant rats.

1979 ◽  
Vol 237 (1) ◽  
pp. E30
Author(s):  
C Y Pang ◽  
H R Behrman
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Corpus Luteum ◽  
Tissue Blood Flow ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Luteal Regression ◽  
Luteal Function ◽  
Arterial Blood ◽  
Relationship Of

An experiment was conducted to examine whether blood flow to corpora lutea may regulate luteal function as judged from plasma levels of progesterone (P) in mature pseudopregnant rats. 141Ce-labeled microspheres (14.1 +/- 0.8 micrometer diam) were used to measure cardiac output and organ and tissue blood flow in rats on days 6, 8, 10, and 12 of pseudopregnancy and in proestrus following luteal regression. The mean arterial blood pressure and cardiac output were similar among all groups of rats. Although a significant (P less than 0.05) decrease in plasma P was observed in rats on day 12 of pseudopregnancy, no change in luteal blood flow or distribution of ovarian blood flow to the corpora lutea was seen at this stage of pseudopregnancy when compared to day 8 or 10 of pseudopregnancy. However, a significant decrease (P less than 0.05) in luteal blood flow was seen in proestrous rats. Because a decrease in plasma progesterone preceded the decrease in luteal blood flow, it was concluded that physiological luteal regression may not be initiated by a reduction of blood flow to the corpus luteum.

Effects of nicotine on canine intestinal blood flow and oxygen consumption

1984 ◽  
Vol 246 (2) ◽  
pp. G195-G203
Author(s):  
R. H. Gallavan ◽  
Y. Tsuchiya ◽  
E. D. Jacobson
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Muscle Tension ◽  
Intestinal Blood Flow ◽  
Mesenteric Blood Flow ◽  
State Response ◽  
Arterial Blood ◽  
Intestinal Circulation

The purpose of this study was to determine the effects of nicotine on intestinal blood flow and oxygen consumption. The intravenous infusion of nicotine at doses corresponding to those experienced by smokers produced a transient increase in systemic arterial blood pressure and mesenteric blood flow. Subsequently a steady-state response developed that consisted of a reduction in mesenteric blood flow due to both a decrease in blood pressure and an increase in intestinal vascular resistance. This increase in resistance was probably due to increased levels of circulating catecholamines. The intra-arterial infusion of nicotine into the intestinal circulation at doses experienced by the average smoker had no effect on either intestinal blood flow or oxygen consumption. Similarly, under in vitro conditions nicotine had no direct effect on intestinal vascular smooth muscle tension. Thus, nicotine appears to reduce intestinal blood flow indirectly as a result of its systemic effects.

Abstract 9934: High Mean Arterial Pressure Aggravates Cerebral Hemodynamics After Extracorporeal Resuscitation in Swine

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
Yael Levy ◽  
Alice Hutin ◽  
Nicolas Polge ◽  
fanny lidouren ◽  
Matthias Kohlhauer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Oxygen Consumption ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Cerebral Hemodynamics ◽  
Reactivity Index ◽  
Extracorporeal Cardiopulmonary Resuscitation ◽  
Standard Map ◽  
Arterial Blood

Introduction: Extracorporeal cardiopulmonary resuscitation (E-CPR) is used for the treatment of refractory cardiac arrest but the optimal target to reach for mean arterial pressure (MAP) remains to be determined. Hypothesis: We hypothesized that MAP levels modify cerebral hemodynamics during E-CPR. Accordingly, we tested two MAP targets (65-75 vs 80-90 mmHg) in a porcine model of E-CPR. Methods: Pigs were anesthetized and instrumented for the evaluation of cerebral and systemic hemodynamics. They were submitted to 15 min of untreated ventricular fibrillation followed by 30 min of E-CPR. Electric attempts of defibrillation were then delivered until resumption of spontaneous circulation (ROSC). Extracorporeal circulation was initially set to an average flow of 40 ml/kg/min with a standardized volume expansion in both groups. The dose of epinephrine was set to reach either a standard or a high MAP target level (65-75 vs 80-90 mmHg, respectively). Animals were followed during 120 min after ROSC. Results: Six animals were included in both groups. After cardiac arrest, MAP was maintained at the expected level (Figure). During E-CPR, high MAP transiently improved carotid blood flow as compared to standard MAP. This blood flow progressively decreased after ROSC in high vs standard MAP, while intra-cranial pressure increased. Interestingly, this was associated with a significant decrease in cerebral oxygen consumption (26±8 vs 54±6 L O 2 /min/kg at 120 min after ROSC, respectively; p<0.01) (Figure). The pressure reactivity index (PRx), which is the correlation coefficient between arterial blood pressure and intracranial pressure, became positive in high MAP (0.47±0.02) vs standard MAP group (-0.16±0.10), demonstrating altered cerebral autoregulation with high MAP. Conclusion: Increasing MAP above 80 mmHg with epinephrine aggravates cerebral hemodynamics after E-CPR. Figure: Mean arterial pressure (MAP), cerebral blood flow and oxygen consumption (*, p<0.05)

Splanchnic blood flow, O2 consumption, removal of lactate, and output of glucose in highlanders

1977 ◽  
Vol 43 (2) ◽  
pp. 204-210 ◽  
Author(s):  
A. Capderou ◽  
J. Polianski ◽  
J. Mensch-Dechene ◽  
L. Drouet ◽  
G. Antezana ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Splanchnic Blood Flow ◽  
O2 Consumption ◽  
Arterial Lactate ◽  
Oxygen Breathing ◽  
Arterial Blood ◽  
Splanchnic Hemodynamics ◽  
Arterial Blood Glucose ◽  
Arteriovenous Difference

An impairment of gluconeogenesis has been proposed to explain the low arterial blood glucose of highlanders. Therefore, we studied splanchnic blood flow, splanchnic uptake of oxygen and lactate, and output of glucose in nine normal and six anemic highlanders at an altitude of 3,750 m. Splanchnic blood flow, arteriovenous difference for oxygen, and oxygen consumption were comparable at rest in both groups and in lowlanders from the literature, whereas splanchnic output of glucose, and uptake of lactate were approximately twice those in lowlanders. After 10 min of mild exercise in 12 subjects (7 normals, 5 anemic), no significant changes in splanchnic hemodynamics and metabolism were found. During 29% oxygen breathing in 8 subjects (5 normals, 3 anemics), arterial lactate, splanchnic uptake of lactate and output of glucose fell to normal sea-level values. We concluded that splanchnic hemodynamics are similar in adapted highlanders and in lowlanders, and that there is no evidence of an impaired gluconeogenesis at the altitude of the present study.

Oxygen consumption and blood flow in the hypothermic, perfused kidney

1959 ◽  
Vol 197 (5) ◽  
pp. 1111-1114 ◽  
Author(s):  
Matthew N. Levy
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Blood Viscosity ◽  
The Body ◽  
Peripheral Artery ◽  
Isolated Kidney ◽  
Arterial Blood ◽  
Oxygen Difference ◽  
Appreciable Reduction

Temperature was diminished in a stepwise fashion in the isolated kidney of the dog perfused from a peripheral artery of the original, normothermic animal. Decreased temperature resulted in an appreciable reduction of renal blood flow at constant arterial blood pressure. Increased blood viscosity and vasoconstriction were both responsible for this reduction of flow. Hypothermia also resulted in a reduction in arteriovenous oxygen difference which was roughly proportional to the centigrade temperature. Furthermore, hypothermia exerted a marked but reversible depression of the rate of oxidative metabolism. This effect was relatively more severe than the changes for the body as a whole at equivalent temperatures reported by other investigators.

Effect of training on epinephrine-stimulated lipolysis determined by microdialysis in human adipose tissue

1995 ◽  
Vol 269 (6) ◽  
pp. E1059-E1066 ◽  
Author(s):  
B. Stallknecht ◽  
L. Simonsen ◽  
J. Bulow ◽  
J. Vinten ◽  
H. Galbo
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Subcutaneous Tissue ◽  
Physical Work ◽  
Tissue Blood Flow ◽  
Epinephrine Infusion ◽  
Arterial Blood ◽  
Adipose Tissue Blood Flow ◽  
Subcutaneous Adipose

Trained humans (Tr) have a higher fat oxidation during submaximal physical work than sedentary humans (Sed). To investigate whether this reflects a higher adipose tissue lipolytic sensitivity to catecholamines, we infused epinephrine (0.3 nmol.kg-1.min-1) for 65 min in six athletes and six sedentary young men. Glycerol was measured in arterial blood, and intercellular glycerol concentrations in abdominal subcutaneous adipose tissue were measured by microdialysis. Adipose tissue blood flow was measured by 133Xe-washout technique. From these measurements adipose tissue lipolysis was calculated. During epinephrine infusion intercellular glycerol concentrations were lower, but adipose tissue blood flow was higher in trained compared with sedentary subjects (P < 0.05). Glycerol output from subcutaneous tissue (Tr: 604 +/- 322 nmol.100 g-1.min-1; Sed: 689 +/- 203; mean +/- SD) as well as arterial glycerol concentrations (Tr: 129 +/- 36 microM; Sed: 119 +/- 56) did not differ between groups. It is concluded that in intact subcutaneous adipose tissue epinephrine-stimulated blood flow is enhanced, whereas lipolytic sensitivity to epinephrine is the same in trained compared with untrained subjects.

Nocturnal variations in human lower leg subcutaneous blood flow related to sleep stages

1992 ◽  
Vol 73 (4) ◽  
pp. 1246-1252 ◽  
Author(s):  
J. H. Sindrup ◽  
J. Kastrup ◽  
P. L. Madsen ◽  
H. Christensen ◽  
B. Jorgensen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
First Episode ◽  
Tissue Blood Flow ◽  
Sleep Stages ◽  
Deep Sleep ◽  
Arterial Blood ◽  
Subcutaneous Blood Flow ◽  
The Moment

Nocturnal subcutaneous adipose tissue blood flow rate was measured in the lower legs of 10 normal human subjects together with systemic arterial blood pressure, heart rate, and registration of sleep stages under ambulatory conditions. The 133Xe washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used for measurement of blood flow rates. The sleep recordings were performed with a portable computerized sleep analysis system. In accordance with the results of previous studies, a hyperemic blood flow rate phase (mean increase 140%) for 100 min was observed approximately 60 min after the subjects went to bed. The moment of onset of the hyperemic phase was closely related to the moment of onset of the first episode of deep sleep (stages 3 and 4). There was a significant (P < 0.01) overrepresentation of deep sleep in the hyperemic phase compared with adjacent phases, and rapid-eye-movement sleep predominantly occurred in the latter part of the night, when the subcutaneous blood flow rate was stable. The results of the present study are in accordance with current theories of the interrelationship between the thermoregulatory and the arousal state control systems and, thus, might suggest that the nightly subcutaneous hyperemia represents a thermoregulatory effector mechanism.

scholarly journals Decrease in heart rates by artificial CO2 hot spring bathing is inhibited by β1-adrenoceptor blockade in anesthetized rats

2004 ◽  
Vol 96 (1) ◽  
pp. 226-232 ◽  
Author(s):  
Masaaki Hashimoto ◽  
Noriyuki Yamamoto
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Skin Color ◽  
Hot Spring ◽  
Tap Water ◽  
Sympathetic Innervation ◽  
Tissue Blood Flow ◽  
Cardiac Sympathetic Innervation ◽  
Human Foot ◽  
Arterial Blood

To investigate the effects of carbon dioxide (CO2) hot spring baths on physiological functions, head-out immersion of urethane-anesthetized, fursheared male Wistar rats was performed. Animals were immersed in water (30 or 35°C) with high-CO2 content (∼1,000 parts/million; CO2-water). CO2-water for bathing was made by using an artificial spa maker with normal tap water and high-pressure CO2 from a gas cylinder. When a human foot was immersed for 10 min in the CO2-water at 35°C, the immersed skin reddened, whereas skin color did not change in normal tap water at the same temperature. Arterial blood pressure, heart rate (HR), underwater skin tissue blood flow, and temperatures of the colon and immersed skin were continuously measured while animals were immersed in a bathtub of water for ∼30 min at room temperature (26°C). Immersed skin vascular resistance, computed from blood pressure and tissue blood flow, was significantly lower in the CO2-water bath than in tap water at 30°C, but no differences were apparent at 35°C. HR of rats in CO2-water was significantly slower than in tap water at 35°C. Decreased HR in CO2-water was inhibited by infusion of atenolol (β1-adrenoceptor blocker), but it was unaffected by atropine (muscarinic cholinoceptor blocker). Theses results suggest that bradycardia in CO2 hot spring bathing is caused by inhibition of the cardiac sympathetic innervation. This CO2-water maker should prove a useful device for acquiring physiological evidence of balneotherapy.

scholarly journals STUDIES ON THE SUPRARENAL CORTEX

1933 ◽  
Vol 58 (1) ◽  
pp. 1-16 ◽  
Author(s):  
George A. Harrop ◽  
Albert Weinstein ◽  
Louis J. Soffer ◽  
John H. Trescher
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Gastrointestinal Tract ◽  
Respiratory Quotient ◽  
Capillary Permeability ◽  
Fatal Outcome ◽  
Arterial Blood

1. The basal oxygen consumption, respiratory quotient, blood flow, blood pressure, and the changes in concentration of the arterial blood were determined in suprarenalectomized dogs (a) when receiving injections of cortical extract (Swingle-Pfiffner), (b) during suprarenal insufficiency induced by withdrawal of the injections, and (c) during the period of recovery brought about by resumption of extract injections. 2. Reasons are advanced for the view that the hemoconcentration which occurs is probably due to loss of fluid through the kidneys, rather than by increased capillary permeability and loss into the tissues, or by loss through the gastrointestinal tract. 3. The loss of fluid from the plasma and tissues will explain the symptoms which follow withdrawal of injections of the hormone, as well as the fatal outcome. The assumption that the suprarenal cortex or its hormone has a detoxifying action upon some product of metabolism is thus rendered unnecessary.

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