EFFECTS OF ACUTE COLD EXPOSURE ON PLASMA CONCENTRATIONS OF NORADRENALINE AND ADRENALINE IN SHEEP

1978 ◽  
Vol 58 (1) ◽  
pp. 23-28 ◽  
Author(s):  
J. R. THOMPSON ◽  
R. J. CHRISTOPHERSON ◽  
V. A. HAMMOND ◽  
G. A. HILLS
Keyword(s):  
Heart Rate ◽  
Cold Stress ◽  
Cold Exposure ◽  
Plasma Glucose ◽  
Plasma Concentrations ◽  
Controlled Environment ◽  
Plasma Catecholamine ◽  
Mean Values ◽  
Environment Chamber ◽  
Plasma Catecholamine Concentrations

Six acute cold trials were performed with mature wethers shorn to a fleece depth of 5–10 mm and maintained in a controlled environment chamber. Heart rate, hematocrit and plasma concentrations of glucose, noradrenaline (NA) and adrenaline (A) were measured during each trial which consisted of a 90-min period at 25 °C, a 150-min period of cold stress (to −19 °C) and a 120-min warming period. All measurements and samples were taken from outside the controlled environment chamber by means of extended conduits to minimize animal disturbance. Mean values at 25 °C were: heart rate 69 beats/min, hematocrit 26.7%, plasma glucose 62 mg/100 ml, NA 0.24 ng/ml and A 0.07 ng/ml. By 120- to 150-min cold exposure, mean values of all variables had increased (P < 0.001) to: heart rate 223 beats/min, hematocrit 33.1%, plasma glucose 115 mg/100 ml, NA 1.11 ng/ml and A 0.24 ng/ml. Following cold exposure, mean values of all variables returned toward pre-cold period values as chamber temperature approached 25 °C. A seventh trial performed at constant temperature (24 °C) demonstrated the marked elevation in plasma catecholamine concentrations when an experimental animal was disturbed. These trials demonstrated: (a) that plasma NA and A concentrations in resting unrestrained ruminants are similar to those of other animals in the same state, (b) that it is important to minimize animal disturbance while studying catecholamines, and (c) that he sympatho-adrenal medullary system is involved in the physiological response of sheep to acute cold stress.

Reflex sympathetic activation in humans is accompanied by inhibition of gastric HCO3- secretion

1988 ◽  
Vol 255 (6) ◽  
pp. G752-G758 ◽  
Author(s):  
H. Sjovall ◽  
H. Forssell ◽  
J. Haggendal ◽  
L. Olbe
Keyword(s):  
Heart Rate ◽  
Vascular Resistance ◽  
Pulse Pressure ◽  
Negative Pressure ◽  
Sympathetic Activity ◽  
Plasma Catecholamine ◽  
Series Of Experiments ◽  
Plasma Catecholamine Concentrations ◽  
Peripheral Sympathetic Activity ◽  
Forearm Vascular Resistance

The study was performed to determine whether the sympathetic nervous system contributes to the reflex control of gastric HCO3- secretion in humans. Gastric HCO3- secretion was registered by a computerized technique based on measurements of pH and PCO2 in gastric effluent. To minimize formation of CO2 in the stomach, subjects were pretreated with the H2-receptor blocker ranitidine. Compensations were made for HCO3- of nongastric origin. As indicators of cardiovascular sympathetic activity, we measured heart rate, forearm vascular resistance, and plasma catecholamine concentrations. In one series of experiments, peripheral sympathetic activity was enhanced by the application of a negative pressure around the lower part of the body (lower body negative pressure, LBNP), at a rate sufficient to induce a slight decrease in systemic arterial pressure. In another series of experiments, peripheral sympathetic activity was inhibited by elevation of the legs, a procedure that simulates volume loading by redistributing blood volume toward the central circulation. LBNP at -20 mmHg decreased systolic pressure and pulse pressure and significantly increased heart rate, forearm vascular resistance, and plasma catecholamine levels. All these effects were observed in the first 15-min period of LBNP and were well maintained throughout the 45-min observation period. LBNP also inhibited basal gastric HCO3- secretion rate in seven of eight individuals, but this response was slower in onset with a latency of at least 15 min. Elevation of the legs increased pulse pressure and decreased forearm vascular resistance. Catecholamines were not measured in these experiments. Gastric HCO3- secretion tended to increase, but the magnitude of the response was highly variable.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Cardiovascular Responses to the Induction of Mild Hypothermia in the Presence of Epidural Anesthesia

2001 ◽  
Vol 94 (4) ◽  
pp. 678-682 ◽  
Author(s):  
Masahiro Yoshida ◽  
Keizo Shibata ◽  
Hironori Itoh ◽  
Ken Yamamoto
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Ejection Fraction ◽  
General Anesthesia ◽  
Epidural Anesthesia ◽  
Mild Hypothermia ◽  
Cardiovascular Response ◽  
Cardiovascular Responses ◽  
Plasma Catecholamine ◽  
Plasma Catecholamine Concentrations

Background The combining of epidural anesthesia with general anesthesia impairs central and peripheral thermoregulatory control and therefore is often accompanied by unintended intraoperative hypothermia. However, little is known about the cardiovascular response to hypothermia during combined epidural and general anesthesia. The authors assessed the effects of hypothermia during such combined anesthesia. Methods The authors randomly assigned 30 mongrel dogs anesthetized with isoflurane (1.0%) to three groups of 10: control, receiving general anesthesia alone; thoracic injection, additionally receiving thoracic epidural anesthesia; and lumbar injection, additionally receiving thoracolumbar epidural anesthesia. Core temperature was lowered from 38.5 degrees C to approximately 34 degrees C (mild hypothermia) using a femoral arteriovenous shunt in an external cool water bath. During hypothermia, the authors measured heart rate, cardiac output, and plasma catecholamine concentrations in each group. Ejection fraction was also measured using echocardiography. Results Compared with measurements during baseline conditions (general anesthesia alone with no epidural injection and no hypothermia) in the control, thoracic, and lumbar injection groups, the injections followed by hypothermia produced 17, 32, and 41% decreases in heart rate; 22, 32, and 47% reductions in cardiac output; 66, 85, and 92% decreases in the epinephrine concentrations; and 27, 44, and 85% decreases in the norepinephrine concentrations. In contrast, ejection fraction did not change in any group. Conclusion Mild hypothermia during combined epidural anesthesia and general anesthesia markedly reduced cardiac output in dogs, mainly by decreasing heart rate.

Pentobarbital effects on plasma catecholamines: temperature, heart rate, and blood pressure

1985 ◽  
Vol 248 (1) ◽  
pp. E95-E100 ◽  
Author(s):  
D. Baum ◽  
J. B. Halter ◽  
G. J. Taborsky ◽  
D. Porte
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Animal Models ◽  
Sympathetic Nervous System ◽  
Rectal Temperature ◽  
Plasma Catecholamines ◽  
Plasma Catecholamine ◽  
Sympathetic Nervous ◽  
Plasma Catecholamine Concentrations

The effects of intravenous pentobarbital were studied in dogs. Plasma pentobarbital concentrations were inversely related to epinephrine and norepinephrine concentrations. Plasma catecholamines appeared fully suppressed at pentobarbital levels greater than 25-30 micrograms/ml. Furthermore, pentobarbital levels were negatively related to rectal temperature, heart rate, and mean blood pressure. The methods of pentobarbital administration influenced plasma pentobarbital as well as epinephrine and norepinephrine levels, temperature, heart rate, and blood pressure. These observations suggest the possibility that pentobarbital inhibits the sympathetic nervous system, which in turn may affect temperature, heart rate, and blood pressure. Because pentobarbital anesthesia affects plasma catecholamine concentrations, the regimen used in animal models requires consideration when interpreting data potentially influenced by the sympathetic nervous system.

scholarly journals Warm Perches: A Novel Approach For Reducing Cold Stress Effect on Production, Plasma Hormones, and Immunity in Laying Hens

2021 ◽  
Author(s):  
Jiaying Hu ◽  
Heng Wei Cheng
Keyword(s):  
Body Weight ◽  
Cold Stress ◽  
Cold Exposure ◽  
Feed Intake ◽  
Plasma Levels ◽  
Egg Production ◽  
Laying Hens ◽  
Plasma Concentrations ◽  
Economic Losses ◽  
Stress Effect

Abstract Background: Cold temperature is a common environmental stressor that has a great impact on the poultry industries, inducing pathophysiological stress in birds with profound economic losses. Current methods used for preventing cold stress, such as reducing ventilation and using gas heaters, are facing challenges due to poor indoor air quality and its deleterious effects on bird and caretaker health. The aim of this study was to examine if the novelly designed warmed perch system, as a thermal device, can reduce cold stress-associated adverse effects on laying hens. Methods: Seventy-two 32-week-old DeKalb hens were randomly assigned to 36 cages arranged to 3 banks. The banks were assigned to 1 of 3 treatments: cages with warmed perches (WP; perches with circulating water at 30 oC), air perches (AP, regular perches only) or no perches (NP) for a 21- day trial. The room temperature was set at 10 oC during the entire experimental period. Rectal temperature and body weight were measured from the same bird of each cage at day 1, 8, 15, and 21 during the cold exposure. Egg production was recorded daily. Feed intake, egg and eggshell quality were determined during the 1st and 3rd week of cold stress. Plasma levels of corticosterone, thyroid hormones (3, 3’, 5-triiodothyronine and thyroxine), interleukin (IL)-6 and IL-10, were determined at day 1 and 21 post initiation of cold exposure. Results: Compared to both AP and NP hens, WP hens were able to maintain their body temperature without increasing feed intake and losing body weight. The eggs laid by WP hens had thicker eggshell during the 3rd week of cold exposure. Warmed perch hens also had a lower thyroxine conversion rate (3, 3’, 5-triiodothyronine/thyroxine) at day 1, while higher plasma concentrations of IL-6 at day 21. Plasma levels of corticosterone, 3, 3’, 5-triiodothyronine, and IL-10 were not different among treatments. Conclusions: Our results indicate that the warmed perch system can be used as a novel thermal device for preventing cold stress-induced negative effects on hen health and welfare through regulating innate immunity and metabolic hormonal homeostasis.

Does Spinal Anesthesia Result in a More Complete Sympathetic Block Than That from Epidural Anesthesia?

1995 ◽  
Vol 82 (4) ◽  
pp. 877-883. ◽  
Author(s):  
Rom A. Stevens ◽  
David Beardsley ◽  
J. Lee White ◽  
Tzu-Cheg Kao ◽  
Rod Gantt ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Spinal Anesthesia ◽  
Epidural Anesthesia ◽  
Conduction Block ◽  
Plasma Catecholamine ◽  
Sympathetic Block ◽  
Plasma Catecholamine Concentrations

Background Spinal and epidural injection of local anesthetics are used to produce sympathetic block to diagnose and treat certain chronic pain syndromes. It is not clear whether either form of regional anesthesia produces a complete sympathetic block. Spinal anesthesia using tetracaine has been reported to produce a decrease in plasma catecholamine concentrations. This has not been demonstrated for epidural anesthesia in humans with level of anesthesia below C8. One possible explanation is that spinal anesthesia results in a more complete sympathetic block than epidural anesthesia. To examine this question, a cross-over study was performed in young, healthy volunteers. Methods Ten subjects underwent both spinal and epidural anesthesia with lidocaine (plain) on the same day with complete recovery between blocks. By random assignment, spinal anesthesia and epidural anesthesia were induced via lumbar injection. Before and 30 min after local anesthetic injection, a cold pressor test (CPT) was performed. Blood was obtained to determine epinephrine and norepinephrine plasma concentrations at four stages: (1) 20 min after placing peripheral catheters, (2) at the end of a 2-min CPT (before conduction block), (3) 30 min after injection of epidural or spinal lidocaine, and (4) at the end of a second CPT (during anesthesia). Mean arterial pressure, heart rate, noninvasive cardiac index, and analgesia to pin-prick were monitored. Results Neither spinal nor epidural anesthesia changed baseline resting values of catecholamines or any hemodynamic variable, except heart rate, which was slightly decreased during spinal anesthesia. Median level of analgesia was T4 during spinal and T3 during epidural anesthesia. CPT before conduction block reliably increased heart rate, mean arterial pressure, cardiac index, epinephrine, and norepinephrine. Conduction block attenuated the increase in response to CPT only in mean arterial pressure (spinal and epidural) and cardiac index (spinal only). Neither technique blocked the increase in heart rate, norepinephrine, or epinephrine to CPT. Conclusions Spinal anesthesia did not result in a more complete attenuation of the sympathetic response to a CPT than did epidural anesthesia. In response to the CPT, spinal anesthesia blocked the increase in cardiac index, and epidural anesthesia resulted in a decrease in total peripheral resistance compared to the pre-anesthesia state. The differences between the techniques are not significant and are of uncertain clinical implications.

scholarly journals Adipose Lipolysis Regulates Cardiac Glucose Uptake and Function in Mice under Cold Stress

2021 ◽  
Vol 22 (24) ◽  
pp. 13361
Author(s):  
Youngshim Choi ◽  
Hyunsu Shin ◽  
Ziwei Tang ◽  
Yute Yeh ◽  
Yinyan Ma ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cold Stress ◽  
Glucose Uptake ◽  
Cold Exposure ◽  
Plasma Concentrations ◽  
Cardiac Metabolism ◽  
Gene Identification ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Glucose Tolerant ◽  
And Function

The heart primarily uses fatty acids as energy substrates. Adipose lipolysis is a major source of fatty acids, particularly under stress conditions. In this study, we showed that mice with selective inactivation of the lipolytic coactivator comparative gene identification-58 (CGI-58) in adipose tissue (FAT-KO mice), relative to their littermate controls, had lower circulating FA levels in the fed and fasted states due to impaired adipose lipolysis. They preferentially utilized carbohydrates as energy fuels and were more insulin sensitive and glucose tolerant. Under cold stress, FAT-KO versus control mice had >10-fold increases in glucose uptake in the hearts but no increases in other tissues examined. Plasma concentrations of atrial natriuretic peptide and cardiac mRNAs for atrial and brain-type natriuretic peptides, two sensitive markers of cardiac remodeling, were also elevated. After one week of cold exposure, FAT-KO mice showed reduced cardiac expression of several mitochondrial oxidative phosphorylation proteins. After one month of cold exposure, hearts of these animals showed depressed functions, reduced SERCA2 protein, and increased proteins for MHC-β, collagen I proteins, Glut1, Glut4 and phospho-AMPK. Thus, CGI-58-dependent adipose lipolysis critically regulates cardiac metabolism and function, especially during cold adaptation. The adipose-heart axis may be targeted for the management of cardiac dysfunction.

Hemodynamic and Catecholamine Responses to Laryngoscopy and Tracheal Intubation in Patients with Complete Spinal Cord Injuries

2001 ◽  
Vol 95 (3) ◽  
pp. 647-651 ◽  
Author(s):  
Kyung Y. Yoo ◽  
JongUn Lee ◽  
Hak S. Kim ◽  
Woong M. Im
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Tracheal Intubation ◽  
Endotracheal Intubation ◽  
Spinal Cord Injuries ◽  
Plasma Concentrations ◽  
Cardiovascular Responses ◽  
Plasma Catecholamine ◽  
Cord Injury

Background Endotracheal intubation in patients undergoing general anesthesia often causes hypertension and tachycardia, which may be altered when the efferent sympathetic fiber to the cardiovascular system is interrupted. The aim of the current study was to investigate the effects of different levels of spinal cord injury on the cardiovascular responses to intubation. Methods Fifty-four patients with traumatic complete cord injuries requiring tracheal intubation were grouped into quadriplegics (above C7; n = 22), high paraplegics (T1-T4, n = 8), and low paraplegics (below T5, n = 24) according to the level of injury. Twenty patients without spinal injury served as controls. Arterial pressure, heart rate, and rhythm were recorded at intervals for up to 5 min after intubation. Plasma concentrations of catecholamines were also measured. Results The intubation increased the systolic blood pressure similarly in control, high-paraplegic, and low-paraplegic groups (P &lt; 0.05), whereas it did not alter the blood pressure in the quadriplegic group. Heart rate was significantly increased in all groups; however, the magnitude was more pronounced in the high-paraplegic group (67%) than in the control (38%) and quadriplegic (33%) groups. Plasma concentrations of norepinephrine were significantly increased after intubation in all groups; however, values were lower in the quadriplegic group and higher in the low-paraplegic group compared with those in the control group. Incidence of arrhythmias did not differ among groups. Conclusions The cardiovascular and plasma catecholamine changes associated with endotracheal intubation may differ according to the affected level in patients with complete spinal cord injuries.

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