Cardiovascular and metabolic responses during burn shock in the guinea pig

1976 ◽  
Vol 231 (3) ◽  
pp. 892-897 ◽  
Author(s):  
RR Wolfe ◽  
HI Miller
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Guinea Pig ◽  
Core Temperature ◽  
Plasma Glucose ◽  
Guinea Pigs ◽  
Tissue Perfusion ◽  
Metabolic Responses ◽  
Burn Shock ◽  
Lactate Levels

The hemodynamic and metabolic responses of fatally burned, nonfatally burned, and unburned control guinea pigs were compared. The burns were induced in temporarily anesthetized animals by immersion to either the xyphoid process (70% fatal) or the midabdomen (100%survival) in boiling water for 3 s. Although cardiac output was reduced in all animals postburn, the survivors (MAG) has higher cardiac outputs at lower arterial pressures than the nonsurvivors (XPN). The postburn lactate levels in the XPN were higher than in the MAG, and the postburn values for pH, oxygen consumption, and core temperature were lower in the XPN. In each group, hyperglycemia was evident for 8 h postburn and terminal plasma glucose concentrations were usually elevated or similar to the prevalue. It was concluded that fatal and nonfatal burn shock were distinguished primarily by differences in tissue perfusion.

Respiratory Metabolism During Pregnancy in the Guinea Pig

1957 ◽  
Vol 190 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Richard M. Hoar ◽  
William C. Young
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Guinea Pig ◽  
Metabolic Rate ◽  
Adrenal Cortex ◽  
Guinea Pigs ◽  
Sharp Decrease ◽  
Zona Fasciculata ◽  
Respiratory Metabolism ◽  
Morphological Differences

Oxygen consumption and heart rate during pregnancy were measured in untreated, thyroxin-injected and thyroidectomized guinea pigs given I131. From impregnation until parturition, oxygen consumption increased 7.9% in untreated females. The increase continued until 5 days postpartum when a sharp decrease occurred. The increase is not accounted for by growth of the fetal mass. Comparable increases occurred in thyroxin-injected (16.2%) and thyroidectomized (11.9%) females, although the levels throughout were higher and lower, respectively, than in intact females. Heart rate did not increase. On the contrary, statistically significant decreases occurred in the untreated and thyroxin-injected females. Although the mechanism associated with the increased metabolic rate is not known, the possibility of thyroid participation would seem to be excluded. Involvement of the adrenal cortex is suggested by morphological differences in the cells of the zona fasciculata in pregnant and nonpregnant females and by evidence cited from other studies.

Effects of restraint on oxygen consumption of the cold exposed guinea pig

1959 ◽  
Vol 14 (1) ◽  
pp. 46-48 ◽  
Author(s):  
R. G. Bartlett
Keyword(s):  
Oxygen Consumption ◽  
Data Collection ◽  
Guinea Pig ◽  
Heat Loss ◽  
Heat Production ◽  
Guinea Pigs ◽  
Muscular Activity ◽  
Physiological Changes

The oxygen consumption of cold exposed, restrained guinea pigs is significantly greater than that of cold exposed, nonrestrained controls. Similar observations have been made for the rat ( Canad. J. Biochem. & Physiol. 33:654, 1955). These data strongly suggest that heat production is greater in the restrained animal than in the nonrestrained control. The hypothermia, then, accompanying restraint in the cold cannot be laid to a decreased muscular activity (muscular activity is actually increased) and a consequently lessened heat production, as suggested by some ( J. Appl. Physiol. 12:214, 1958). It must be due, as demonstrated for the rat ( Am. J. Physiol. 193:557, 1958), to an increased rate of heat loss. The marked physiological changes accompanying restraint should serve as a warning to the investigator who uses restraint for convenience in data collection. Submitted on July 11, 1958

scholarly journals Do cardiorespiratory frequencies show entrainment with hopping in the tammar wallaby?

1987 ◽  
Vol 129 (1) ◽  
pp. 251-263 ◽  
Author(s):  
R. V. Baudinette ◽  
B. J. Gannon ◽  
W. B. Runciman ◽  
S. Wells ◽  
J. B. Love
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Arterial Pressure ◽  
Tidal Volume ◽  
Tammar Wallaby ◽  
Metabolic Power ◽  
Macropus Eugenii ◽  
Speed Range ◽  
Lactate Levels ◽  
Blood Lactate Levels

Breathing, heart and gait frequencies, tidal volume, cardiac output, and rates of oxygen consumption were measured in tammar wallabies (Macropus eugenii Desmarest) hopping on a treadmill. At speeds greater than 1.6 ms-1 the rate of metabolic power consumption was independent of hopping speeds. Blood lactate levels within the speed range where VO2 was independent of speed showed a mean increase of 4.8 mmol l-1. During bipedal hopping, the frequencies of breathing and limb movement are phase-locked in the ratio of 1:1. Inspiration begins as the animal leaves the ground and may be a passive process driven by a visceral piston. A relatively large central tendon in the diaphragm may correlate this function. Unlike breathing frequencies, cardiac frequencies show no entrainment with hopping. The site of dissipation of the presumed large arterial pressure excursion is unknown.

Measurement of Oxygen Consumption and Arterial-Venous Oxygen Saturation following Total Artificial Heart Implantation

1993 ◽  
Vol 16 (3) ◽  
pp. 135-140 ◽  
Author(s):  
P.D. Robison ◽  
G.M. Pantalos ◽  
J.W. Long ◽  
R.S. Bliss ◽  
D.K. Price ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Oxygen Delivery ◽  
Artificial Heart ◽  
Tissue Perfusion ◽  
Oxygen Metabolism ◽  
Total Artificial Heart ◽  
Oxygen Utilization ◽  
Venous Oxygen Saturation ◽  
Mixed Venous

Current algorithms for control of the total artificial heart are directed at maintaining hemodynamic homeostasis. Future control systems will also need to modify cardiac output in response to metabolic needs. This study was undertaken to evaluate oxygen metabolism monitoring as an indicator of the adequacy of organ and tissue perfusion. Following recovery from implantation of the Utah-100 pneumatic total artificial hearts, five calves (85 to 95 kg) underwent placement of fiberoptic oxymetry catheters to determine mixed venous and arterial oxygen saturations. By continuously measuring oxygen consumption with a gas analyzer, oxygen utilization and delivery were determined. In the awake calves, at-rest cardiac output was varied to produce hyperperfused and hypoperfused conditions while the adequacy of tissue perfusion was assessed with continuous mixed venous oxymetry and confirmed with serum lactate (Lact) levels. Inadequate tissue perfusion (Lact > 1.0 mmol/L) was evidenced by a mixed venous oxygen saturation <40%, oxygen delivery of < 200.0 milliliters/minute/m2), and oxygen delivery to utilization ratio of < 1.8 during the hypoperfusion conditions of the experiment. By accounting for oxygen consumption, the ratio of oxygen delivery to oxygen utilization was predictive of the adequacy of tissue perfusion. These results suggest that continuous oxygen metabolism monitoring may be useful as a physiologic control modifier to maintain total artificial heart output sufficient to meet physiologic needs, while avoiding hyperperfusion, unnecessary wear and deterioration of the implanted device due to excessive heart rates.

scholarly journals Naloxone does not alter the “regulated” decrease in core temperature during hypoxemia in guinea pigs

1998 ◽  
Vol 85 (3) ◽  
pp. 1150-1159 ◽  
Author(s):  
Kim C. Crisanti ◽  
James E. Fewell
Keyword(s):  
Oxygen Consumption ◽  
Core Temperature ◽  
Guinea Pigs ◽  
Recovery Period ◽  
Control Period ◽  
Temperature Response ◽  
Experimental Period ◽  
Endogenous Opioids ◽  
Opioid Antagonist ◽  
Linear Temperature

In newborns and adults of a number of species, exposure to acute hypoxemia produces a “regulated” decrease in core temperature, the mechanism of which is unknown. The present experiments were carried out in chronically instrumented newborn (5–10 days of age; n = 59) and older (25–30 days of age; n = 61) guinea pigs to test the hypothesis that the endogenous opioids mediate this regulated decrease in core temperature. During an experiment, core temperature, oxygen consumption, and selected ambient temperature were measured in a thermocline (linear temperature gradient of 10–40°C) during a control period of normoxemia, an experimental period of normoxemia or hypoxemia (inspired oxygen fraction 0.10), and during a recovery period of normoxemia following an intraperitoneal injection of naloxone hydrochloride (a nonspecific opioid antagonist; 1, 2, or 4 mg/kg) or vehicle. Naloxone did not significantly alter basal core temperature or the core temperature response to acute hypoxemia in newborn or older guinea pigs. Naloxone did, however, decrease basal oxygen consumption in newborn and older guinea pigs and altered the thermoregulatory effector mechanism used to decrease core temperature during hypoxemia in the newborn guinea pigs. Our data do not support the hypothesis that the endogenous opioids mediate the regulated decrease in core temperature that occurs in newborn and older guinea pigs during exposure to acute hypoxemia.

Effect of Novel Situation and Modification in Sexual Drive on Rate of Oxygen Consumption in Guinea Pigs

1964 ◽  
Vol 15 (1) ◽  
pp. 311-317 ◽  
Author(s):  
Arnold A. Gerall ◽  
William S. Berg
Keyword(s):  
Oxygen Consumption ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Mature Male ◽  
Normal Rate ◽  
The Novel ◽  
Sexual Drive ◽  
Copulatory Pattern ◽  
Rate Of Oxygen Consumption

The normal rate of O2 consumption of 10 mature male guinea pigs was compared with that produced during the first several days in the novel situation and by sexual satiation and frustration. A higher than normal rate of O2 consumption recorded on the first day was followed by a lower than normal rate on the second and third days. Neither sexual satiation derived from ejaculation nor frustration produced by interrupting the copulatory pattern after the first intromission was found to modify significantly the normal rate of metabolism. In an attempt to explain these results, several hypotheses were suggested based on either the tendency of the guinea pig to crouch when frightened or the nature of the stimuli in the chamber of the metabolism apparatus.

Hemodynamic and metabolic responses to self-paced and ramp-graded exercise testing protocols

2018 ◽  
Vol 43 (6) ◽  
pp. 609-616 ◽  
Author(s):  
Nicholas M. Beltz ◽  
Fabiano T. Amorim ◽  
Ann L. Gibson ◽  
Jeffrey M. Janot ◽  
Len Kravitz ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Exercise Testing ◽  
Ventilatory Threshold ◽  
Maximal Oxygen Consumption ◽  
Oxygen Uptake Kinetics ◽  
Metabolic Responses ◽  
Graded Exercise Testing ◽  
Graded Exercise

Recent examinations have shown lower maximal oxygen consumption during traditional ramp (RAMP) compared with self-paced (SPV) graded exercise testing (GXT) attributed to differences in cardiac output. The current study examined the differences in hemodynamic and metabolic responses between RAMP and SPV during treadmill exercise. Sixteen recreationally trained men (aged23.7 ± 3.0 years) completed 2 separate treadmill GXT protocols. SPV consisted of five 2-min stages (10 min total) of increasing speed clamped by the Borg RPE6-20 scale. RAMP increased speed by 0.16 km/h every 15 s until volitional exhaustion. All testing was performed at 3% incline. Oxygen consumption was measured via indirect calorimetry; hemodynamic function was measured via thoracic impedance and blood lactate (BLa−) was measured via portable lactate analyzer. Differences between SPV and RAMP protocols were analyzed as group means by using paired-samples t tests (R Core Team 2017). Maximal values for SPV and RAMP were similar (p > 0.05) for oxygen uptake (47.1 ± 3.4 vs. 47.4 ± 3.4 mL·kg−1·min−1), heart rate (198 ± 5 vs. 200 ± 6 beats·min−1), ventilation (158.8 ± 20.7 vs. 159.3 ± 19.0 L·min−1), cardiac output (26.9 ± 5.5 vs. 27.9 ± 4.2 L·min−1), stroke volume (SV) (145.9 ± 29.2 vs. 149.8 ± 25.3 mL·beat−1), arteriovenous oxygen difference (18.5 ± 3.1 vs. 19.7 ± 3.1 mL·dL−1), ventilatory threshold (VT) (78.2 ± 7.2 vs. 79.0% ± 7.6%), and peak BLa− (11.7 ± 2.3 vs. 11.5 ± 2.4 mmol·L−1), respectively. In conclusion, SPV elicits similar maximal hemodynamic responses in comparison to RAMP; however, SV kinetics exhibited unique characteristics based on protocol. These results support SPV as a feasible GXT protocol to identify useful fitness parameters (maximal oxygen uptake, oxygen uptake kinetics, and VT).

Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

1983 ◽  
Vol 41 ◽  
pp. 726-727
Author(s):  
Corazon D. Bucana
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Electron Density ◽  
Peritoneal Cavity ◽  
Ultrastructural Study ◽  
Guinea Pigs ◽  
Random Distribution ◽  
Glycogen Content ◽  
Polymorphonuclear Neutrophils ◽  
Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

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