Relationship of pyruvate and lactate during anaerobic metabolism. V: Coronary adequacy

1961 ◽  
Vol 200 (6) ◽  
pp. 1169-1176 ◽  
Author(s):  
William E. Huckabee
Keyword(s):  
Blood Flow ◽  
Coronary Flow ◽  
Cardiac Tissue ◽  
Anaerobic Metabolism ◽  
Constant Ratio ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Relationship Of ◽  
The Relationship

Veno-arterial differences of pyruvate and lactate across the myocardium in chloralose-anesthetized dogs were very variable; in any one animal they changed continually with time despite constant blood flow and arterial blood concentrations. There was a systematic tendency of v-a lactate to vary with v-a pyruvate, as expressed in the calculated "Δ excess lactate," which remained nearly constant (or, if blood flow changed, bore a constant ratio to (a-v)O2). No change in Δ excess lactate from control values occurred in nonhypoxic experiments despite marked changes in v-a differences, arterial blood composition, and coronary flow. Cardiac Δ excess lactate became positive in most animals breathing 10% O2 in N2; output of excess lactate was also observed in all those in which moderate muscular exercise was induced. This anaerobic metabolism, or change in the relationship between pyruvate and lactate exchanges, was interpreted as an indication that O2 delivery response was not adequate to meet cardiac tissue requirements during such mild stresses when judged by the standards of adequacy of the basal state.

ON THE RELATIONSHIP BETWEEN TESTICULAR BLOOD FLOW AND SECRETION OF TESTOSTERONE IN ANESTHETIZED DOGS STIMULATED WITH HUMAN CHORIONIC GONADOTROPHIN

1964 ◽  
Vol 42 (5) ◽  
pp. 671-677 ◽  
Author(s):  
Kristen B. Eik-Nes
Keyword(s):  
Blood Flow ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Arterial Blood Flow ◽  
Constant Infusion ◽  
Left Testis ◽  
Arterial Blood ◽  
Constant Rate ◽  
Anesthetized Dogs ◽  
The Relationship

The concentration of testosterone has been measured in spermatic vein blood from the left testis in 25 anesthetized dogs, stimulated with human chorionic gonadotrophin and infused with arterial blood via the left spermatic artery at different rates. The secretion of testosterone varied with the rate at which arterial blood was infused and at a constant infusion rate of 3.81 ml/min, animals weighing from 19 to 23 kg produced testosterone at a constant rate over 90 minutes. Infusion rates lower than this decreased the secretion of testosterone, and if arterial blood was infused at a rate of 0.76 ml/min for the first 30 minutes of experimentation, the capacity of the infused testis to secrete testosterone in the ensuing 60 minutes was impaired even in animals given large doses of human chorionic gonadotrophin via the left spermatic artery. A relationship between the arterial blood flow to the testis and its ability to secrete testosterone under the influence of human chorionic gonadotrophin is thus established.

Autoregulation of renal blood flow in the rat: effects of growth and uninephrectomy

1983 ◽  
Vol 244 (5) ◽  
pp. F483-F487 ◽  
Author(s):  
R. L. Chevalier ◽  
D. L. Kaiser
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Young Animal ◽  
Normal Growth ◽  
Sham Operation ◽  
Adult Rats ◽  
Arterial Blood ◽  
Relationship Of ◽  
The Relationship

As a result of normal maturation or after reduction in renal mass, renal blood flow (RBF) progressively increases. However, the effects of renal growth on the relationship of RBF to renal perfusion pressure (RPP) have not been systematically investigated. We examined RBF as a function of RPP in anesthetized young and adult rats that had been subjected to uninephrectomy or sham operation 3-4 wk previously. As a result of normal growth, mean arterial blood pressure increased from 94.1 +/- 2.7 (SE) to 118.9 +/- 4.2 mmHg. The calculated autoregulation factor, in which a value less than 1 indicates the presence of autoregulation, was 0.44 +/- 0.10 over RPP 70-100 mmHg and 1.74 +/- 0.25 over RPP 40-70 mmHg in sham-operated young animals. In adult sham-operated rats, the factor was 0.38 +/- 0.07 over RPP 100-130 mmHg and 1.03 +/- 0.07 over RPP 70-100 mmHg. Uninephrectomy in adults resulted in a 30% rise in RBF over RPP 100-130 mmHg, and there was no change in the autoregulation factor. Uninephrectomy in young rats, however, resulted in a 35% rise in RBF at RPP = 100 mmHg with only a 17% rise at RPP = 70 mmHg, and the autoregulation factor increased to 0.91 +/- 0.10 over this range of RPP. We conclude that the autoregulatory range shifts with increasing blood pressure during normal growth and that autoregulation is "reset" to higher RBF in the uninephrectomized adult rat. Although autoregulation takes place in the young animal, uninephrectomy alters the relationship of RBF to RPP such that autoregulation is impaired.

scholarly journals Critical Closing Pressure Determined with a Model of Cerebrovascular Impedance

2012 ◽  
Vol 33 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Georgios V Varsos ◽  
Hugh Richards ◽  
Magdalena Kasprowicz ◽  
Karol P Budohoski ◽  
Ken M Brady ◽  
...  
Keyword(s):  
Blood Flow ◽  
The Novel ◽  
Brain Vessels ◽  
Arterial Blood ◽  
Critical Closing Pressure ◽  
Physiological Values ◽  
Relationship Of ◽  
The Relationship ◽  
Closing Pressure ◽  
Brain Monitoring

Critical closing pressure (CCP) is the arterial blood pressure (ABP) at which brain vessels collapse and cerebral blood flow (CBF) ceases. Using the concept of impedance to CBF, CCP can be expressed with brain-monitoring parameters: cerebral perfusion pressure (CPP), ABP, blood flow velocity (FV), and heart rate. The novel multiparameter method (CCPm) was compared with traditional transcranial Doppler (TCD) calculations of CCP (CCP1). Digital recordings of ABP, intracranial pressure (ICP), and TCD-based FV from previously published studies of 29 New Zealand White rabbits were reanalyzed. Overall, CCP1 and CCPm showed correlation across wide ranges of ABP, ICP, and PaCO2 ( R = 0.93, P < 0.001). Three physiological perturbations were studied: increase in ICP ( n = 29) causing both CCP1 and CCPm to increase ( P < 0.001 for both); reduction of ABP ( n = 10) resulting in decrease of CCP1 ( P = 0.006) and CCPm ( P = 0.002); and controlled increase of PaCO2 ( n = 8) to hypercapnic levels, which decreased CCP1 and CCPm, albeit insignificantly ( P = 0.123 and P = 0.306 respectively), caused by a spontaneous significant increase in ABP ( P = 0.025). Multiparameter mathematical model of critical closing pressure explains the relationship of CCP on brain-monitoring variables, allowing the estimation of CCP during cases such as hypercapnia-induced hyperemia, where traditional calculations, like CCP1, often reach negative non-physiological values.

The effects of mass-induced intracranial pressures on arterial hypertension and survival in awake cats

1972 ◽  
Vol 37 (5) ◽  
pp. 514-527 ◽  
Author(s):  
Stanley J. Goodman ◽  
Donald P. Becker ◽  
John Seelig
Keyword(s):  
Intracranial Pressure ◽  
Systemic Hypertension ◽  
Content Type ◽  
Arterial Blood ◽  
Mass Size ◽  
Intracranial Pressures ◽  
Relationship Of ◽  
The Relationship ◽  
Awake Cats ◽  
Supratentorial Mass

✓ Intracranial pressures above and below the tentorium, arterial blood pressure, heart rate, and respiratory rate were recorded continuously before, during, and after expansion of a supratentorial mass in awake unsedated cats. In general, as the mass enlarged, the intracranial pressure rose; however, considerable variation was observed among animals with respect to specific mass size and associated intracranial pressures. There was considerable variation in the relationship of supratentorial pressure to infratentorial pressure. No animal survived that had sustained a mass-induced pressure exceeding 1100 mm H2O, and survival was shorter with greater pressures. Systemic hypertension occurred always and only when the infratentorial pressure exceeded 600 mm H2O, regardless of the magnitude of the associated supratentorial intracranial pressure. The methodological limitations of previous studies of mass-induced intracranial hypertension appear to have been substantially reduced by the technique described.

Relationship between portal venous and hepatic arterial blood flows: spectrum of response

1990 ◽  
Vol 259 (6) ◽  
pp. G1010-G1018 ◽  
Author(s):  
T. Kawasaki ◽  
F. J. Carmichael ◽  
V. Saldivia ◽  
L. Roldan ◽  
H. Orrego
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
Portal Vein Ligation ◽  
Artery Ligation ◽  
Blood Flows ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Relationship ◽  
Group D

The relationship between portal tributary blood flow (PBF) and hepatic arterial blood flow (HAF) was studied in awake, unrestrained rats with the radiolabeled microsphere technique. Six distinct patterns of response emerged. In group A (PBF+, HAF 0), ethanol, acetate, glucagon, prostacyclin, and a mixed diet increased PBF without a change in HAF; in group B (PBF+, HAF+), adenosine and histamine increased both PBF and HAF; in group C (PBF 0, HAF+), isoflurane and triiodothyronine did not change PBF but increased HAF; and in group D (PBF-, HAF+), halothane and vasopressin decreased PBF and increased HAF. Acute partial portal vein ligation decreased PBF (56%) and increased HAF (436%). Hypoxia (7.5% O2) decreased PBF (28%) and increased HAF (110%). In group E (PBF+, HAF-), acute hepatic artery ligation increased PBF (35%) and reduced HAF (74%), while in group F (PBF-, HAF-), thyroidectomy reduced PBF and HAF (36 and 47%, respectively). All blood flow responses were accompanied by the expected changes in both portal tributary and hepatic arterial vascular resistances. The data suggest that the portal and hepatic arterial vascular territories have regulatory mechanisms that allow for independent changes.

Relation of blood flow to VO2, PO2, and PCO2 in dog gastrocnemius muscle

1988 ◽  
Vol 255 (5) ◽  
pp. H1004-H1010 ◽  
Author(s):  
D. E. Mohrman ◽  
R. R. Regal
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Carbon Dioxide Tension ◽  
Experimental Conditions ◽  
Muscle Oxygen ◽  
Muscle Oxygen Consumption ◽  
Relationship Of ◽  
The Relationship

We pump-perfused gastrocnemius-plantaris muscle preparations at constant pressure to study the relationship of muscle blood flow (Q) to muscle oxygen consumption (VO2), venous oxygen tension (PVO2), and venous carbon dioxide tension (PVCO2) during steady-state exercise at different rates. Tests were performed under four experimental conditions produced by altering the perfusate blood-gas status with a membrane lung. The consistency of the relationship of Q to other variables was evaluated by statistical analysis of fitted curves. Not one of the above listed variables had the same relationship with Q in all four of the experimental conditions we tested. However, we did find that a consistent relationship existed among Q, PVO2, and PVCO2 in our data. That relationship is well described by the equation (Q-23).[PVO2 - (0.5.PVCO2) - 3] = 105 (when Q is expressed in ml.100 g-1.min-1 and PVO2 and PVCO2 in mmHg). One interpretation of this result is that both PO2 and PCO2 are important variables in the control of blood flow in skeletal muscle the combined influence of which could account for nearly all of the hyperemia response to steady-state muscle exercise.

Relation of local skin temperature and local sweating to cutaneous blood flow

1963 ◽  
Vol 18 (4) ◽  
pp. 781-785 ◽  
Author(s):  
Leo C. Senay ◽  
Leon D. Prokop ◽  
Leslie Cronau ◽  
Alrick B. Hertzman
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Sweat Gland ◽  
Cutaneous Blood Flow ◽  
Local Skin ◽  
Cutaneous Vasodilatation ◽  
Local Skin Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Cutaneous Blood

The relationship of local skin temperature and the onset of sweating to the local cutaneous blood flow was studied in the forearm and calf. The purpose of the investigation was to appraise the possible relation of sweat gland activity to the cutaneous vasodilatation which has been attributed to bradykinin or to intracranial temperatures. The onset of sweating was not marked by any apparently related increases in the rate of cutaneous blood flow. On the contrary, the onset of sweating was followed often by a stabilization or even a decrease in the level of cutaneous blood flow. The relations of the latter to the local skin temperature were complex, particularly in the forearm. There appeared to be additional unidentified influences, possibly vasomotor, operating on the skin vessels during transitional phases in the relation of skin temperature to blood flow. Submitted on October 15, 1962

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