THE EFFECTS OF MEPROBAMATE ON PHYSIOLOGICAL RESPONSES TO COLD

1965 ◽  
Vol 43 (3) ◽  
pp. 457-461 ◽  
Author(s):  
P. F. Iampietro ◽  
V. Fiorica ◽  
R. Dille ◽  
E. A. Higgins
Keyword(s):  
Cold Exposure ◽  
Physiological Responses ◽  
Cardiovascular Responses ◽  
Subsequent Increase ◽  
Exposure To Cold

Meprobamate (800 mg) depresses both respiratory and cardiovascular responses of men during exposure to neutral (80 °F, 26.7 °C) and cold (50 °F, 10.0 °C) environments. The inhibition of these responses is most severe during exposure to cold when the usual compensatory increases elicited by this stress are minimized. Drug-treated subjects effect only small increases in systolic and diastolic pressures during cold exposure and virtually no change in heart and respiratory rates. Although rectal temperatures of both drug and placebo groups decrease uniformly during exposure to a neutral environment, the subsequent increase stimulated by cold exposure is depressed in meprobamate-treated subjects. No differences in the hematocrit increase induced by cold exposure were detected between drug and placebo groups.

Tolerance of estrogen-treated rats to acute cold exposure

1979 ◽  
Vol 47 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M. J. Fregly ◽  
D. L. Kelleher ◽  
D. J. Black
Keyword(s):  
Oxygen Consumption ◽  
Cold Exposure ◽  
Previous Experiment ◽  
Female Rats ◽  
Control Group ◽  
Maximal Rate ◽  
Acute Cold Exposure ◽  
Exposure To Cold ◽  
Rate Of Oxygen Consumption ◽  
Rate Of Cooling

Female rats treated chronically with ethynylestradiol (36 micrograms/kg per day) alone, and in combination with the progestational agent, norethynodrel (253 micrograms/kg per day), cooled significantly faster than controls when lightly restrained and exposed to air at 5 degrees C. Rate of cooling of rats given only norethynodrel was similar to that of the control group. In other studies, rate of oxygen consumption was determined for all groups during acute exposure to cold (14 degrees C). All estrogen-treated groups achieved the same maximal rate of oxygen consumption as control and norethynodrel-treated groups during cold exposure, but cooled significantly faster. Two groups of female rats were treated chronically with ethynylestradiol at two separate doses (36 and 61 micrograms/kg per day). An untreated group served as controls. Rate of oxygen consumption of all animals were measured during restraint and exposure to cold (18 degrees C). The estrogen-treated groups again achieved the same maximal rate of oxygen consumption as the control group, but also cooled significantly faster despite the fact that the cold stress was less severe than in the previous experiment. That estrogen-treated rats cooled faster than controls in both studies despite achieving a maximal rate of heat production which did not differ from controls suggests that reduced cold tolerance of estrogen-treated rats may be related to increased heat loss.

Effect of Extreme Cold Exposure on Adrenocortical Function in the Unanesthetized Dog

1956 ◽  
Vol 185 (2) ◽  
pp. 239-242 ◽  
Author(s):  
Richard H. Egdahl ◽  
John B. Richards
Keyword(s):  
Cold Exposure ◽  
Venous Blood ◽  
Adrenocortical Function ◽  
Subsequent Increase ◽  
Adrenal Steroid ◽  
Temperature Ranges ◽  
Exposure Levels ◽  
Healthy Dogs ◽  
The Right ◽  
Environmental Temperatures

Unanesthetized dogs with polyethylene cannulas in the right lumboadrenal vein were subjected to environmental temperatures of –46 to –50°C for 2–28 hours and –75 to –79°C for 4–5 hours. Adrenal venous blood samples were collected prior to, and during the periods of cold exposure, and analyzed for 17-hydroxycorticosteroids. In both temperature ranges, a marked increase in adrenal steroid output occurred soon after the onset of exposure in the 10 dogs studied. In 9 of the 10 animals, this response persisted for 1–3 hours after which adrenal steroid secretion returned to control, pre-exposure levels, despite continued cold exposure. The intravenous administration of 40 iu of ACTH produced a subsequent increase in adrenal 17-hydroxycorticosteroid output. Healthy dogs exposed to temperatures of –47°C for 28 hours and –79°C for 5 hours did not become hypothermic.

Physiological Responses and Perceived Exertion During International Taekwondo Competition

2009 ◽  
Vol 4 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Craig A. Bridge ◽  
Michelle A. Jones ◽  
Barry Drust
Keyword(s):  
Blood Lactate ◽  
Perceived Exertion ◽  
Anaerobic Metabolism ◽  
Physiological Responses ◽  
Cardiovascular Responses ◽  
Capillary Blood ◽  
Rating Of Perceived Exertion ◽  
International Level ◽  
Combat Training ◽  
Aerobic And Anaerobic

Purpose:To investigate the physiological responses and perceived exertion during international Taekwondo competition.Methods:Eight male Taekwondo black belts (mean ± SD, age 22 ± 4 y, body mass 69.4 ± 13.4 kg, height 1.82 ± 0.10 m, competition experience 9 ± 5 y) took part in an international-level Taekwondo competition. Each combat included three 2-min rounds with 30 s of recovery between each round. Heart rate (HR) was recorded at 5-s intervals during each combat. Capillary blood lactate samples were taken from the fingertip 1 min before competition, directly after each round and 1 min after competition. Competitors’ rating of perceived exertion (RPE) was recorded for each round using Borg’s 6-to-20 scale.Results:HR (round 1: 175 ± 15 to round 3: 187 ± 8 beats·min−1; P < .05), percentage of HR maximum (round 1: 89 ± 8 to round 3: 96 ± 5% HRmax; P < .05), blood lactate (round 1: 7.5 ± 1.6 to round 3: 11.9 ± 2.1 mmol·L-1; P < .05) and RPE (round 1: 11 ± 2 to round 3: 14 ± 2; P < .05; mean ± SD) increased significantly across rounds.Conclusions:International-level Taekwondo competition elicited near-maximal cardiovascular responses, high blood lactate concentrations, and increases in competitors' RPE across combat. Training should therefore include exercise bouts that sufficiently stimulate both aerobic and anaerobic metabolism.

EFFECT OF THE EXPOSURE TO COLD ON THE EXTRATHYROIDAL CONVERSION OF L-THYROXINE TO TRIIODO-L-THYRONINE, AND ON INTRAMITOCHONDRIAL α-GLYCEROPHOSPHATE DEHYDROGENASE ACTIVITY IN THYROIDECTOMIZED RATS ON L-THYROXINE

1975 ◽  
Vol 78 (3) ◽  
pp. 481-492 ◽  
Author(s):  
J. Bernal ◽  
F. Escobar del Rey
Keyword(s):  
Dehydrogenase Activity ◽  
Paper Chromatography ◽  
Cold Exposure ◽  
Isotopic Equilibrium ◽  
Glycerophosphate Dehydrogenase ◽  
Exposure To Cold ◽  
Constant Dose ◽  
And Control

ABSTRACT Thyroidectomized rats have been injected daily with 125I labelled L-thyroxine (T4*) and, once isotopic equilibrium was attained, divided into cold-exposed (4–10°C) and control (21–24°C) groups, the daily T4* administration being continued till the end of the experiment. Fourteen days after onset of cold exposure, the total I* of different organs and of the carcass was determined and the tissues submitted to extraction and paper chromatography for the separation of T4 and T4-derived I-containing compounds. The activity of intramitochondrial α-glycerophosphate dehydrogenase (α-GPD) was measured in kidneys and liver. It was found that the total amount of I* was intensely decreased in all samples from cold-exposed animals. The proportion of this I* which was non-extractable was the same, in all tissues, for cold-exposed and control rats. The % of extractable tissue radioactivity in the form of T4 was decreased, and that found as T4-derived T3 was increased, in all samples from cold-exposed animals. The T3/T4 ratio was increased more than two-fold in all tissues studied. The concentration of T4 decreased significantly in all tissues, whereas the concentration of T3 in tissues of cold-exposed rats did not decrease. It actually increased in kidneys and lungs, and remained the same in liver and carcass. Despite the decrease in the concentration of T4 in the kidneys, α-GPD activity was increased in this tissue, where the concentration of T3 was increased. No change in the α-GPD activity was found for the liver, where the concentration of T3 was the same for cold-exposed and control rats. Thus, it appears likely that the conversion of T4 to T3 is increased by the exposure to cold of thyroidectomized rats on a constant dose of T4. α-GPD activity in a given tissue appears to be more closely related to the concentration of T3, than to that of T4.

Cold-Induced Skin Disorders

1996 ◽  
Vol 1 (2) ◽  
pp. 119-130
Author(s):  
H.L. Kim ◽  
Y. Bo-Abbas ◽  
Lyn C. Guenther
Keyword(s):  
Cold Exposure ◽  
Clinical Presentation ◽  
Heterogeneous Group ◽  
Current Understanding ◽  
Cold Climates ◽  
Skin Disorders ◽  
Cold Temperatures ◽  
Exposure To Cold

Background: Humans are commonly exposed to extremes in temperature. Fortunately, our skin behaves as an anatomic and physiologic barrier during these periods. Exposure to cold temperatures may result in a variety of symptoms and disorders. Objective: Our current understanding of the pathophysiology, clinical presentation, and therapies of cold-induced skin disorders are reviewed. Methods: Studies, reviews, and book chapters that contained information on cold-induced skin disorders were reviewed. Conclusion: Cold-induced skin disorders are a heterogeneous group of disorders that cause great morbidity, particularly in cold climates. These entities can be classified as physiologic or pathologic responses to freezing or nonfreezing cold exposure.

scholarly journals Changes in rat pituitary POMC mRNA after exposure to cold or a novel environment, detected by in situ hybridization.

1991 ◽  
Vol 39 (6) ◽  
pp. 843-852 ◽  
Author(s):  
P Wu ◽  
G V Childs
Keyword(s):  
Cold Exposure ◽  
Color Image ◽  
Fold Increase ◽  
Male Rats ◽  
Image Analysis System ◽  
Frozen Sections ◽  
Novel Environment ◽  
Pomc Mrna ◽  
Exposure To Cold

Plasma adrenocorticotropin (ACTH) levels increase after acute cold exposure. The purpose of this study was to determine if there were parallel changes in pituitary proopiomelanocortin (POMC) mRNA. Male rats were exposed to cold (3-5 degrees C) or a novel environment for 15 or 30 min. Others were unstressed. POMC mRNAs in frozen sections or dissociated cells were hybridized with a photobiotinylated oligonucleotide probe which was detected in situ by streptavidin-alkaline phosphatase. The percentage of area labeled for POMC mRNA was quantified by the Cue-3 color image analysis system. In frozen sections, 24-fold increases in the percentage of area labeled for POMC mRNA were evident in intermediate lobes (IL) 30 min after stress. No change was seen in anterior lobes (AL). If the ALs were dissociated, a 66-99% increase in percentage of labeled cells was detected 2-3 hr after the cold exposure. Fifteen min of cold stress (CS) also caused a 117% increase in the area of label for POMC mRNA per corticotrope. No change was seen after 30 min. Exposure to a novel environment caused a 73% increase in the percentage of area labeled for POMC mRNA per AL corticotrope and an 11-fold increase in the IL. These results indicate that both AL corticotropes and IL melanotropes are stimulated by acute exposure to cold and novel environments.

THE EFFECTS OF NICOTINE ON THE CARDIOVASCULAR RESPONSES DURING ACUTE COLD EXPOSURE

2002 ◽  
Vol 34 (5) ◽  
pp. S144
Author(s):  
C C. Cheatham ◽  
N Caine ◽  
M Blegen ◽  
E S. Potkanowicz ◽  
E L. Glickman
Keyword(s):  
Cold Exposure ◽  
Cardiovascular Responses ◽  
Acute Cold Exposure

Emotional and psychophysiological responses to tempo, mode, and percussiveness

2011 ◽  
Vol 15 (2) ◽  
pp. 250-269 ◽  
Author(s):  
Marjolein D. van der Zwaag ◽  
Joyce H.D.M. Westerink ◽  
Egon L. van den Broek
Keyword(s):  
Skin Conductance ◽  
Emotional State ◽  
Physiological Responses ◽  
Cardiovascular Responses ◽  
Self Report ◽  
Laboratory Setting ◽  
Psychophysiological Responses ◽  
Skin Conductance Responses ◽  
Major Mode ◽  
Musical Characteristics

People often listen to music to influence their emotional state. However, the specific musical characteristics which cause this process are not yet fully understood. We have investigated the influence of the musical characteristics of tempo, mode, and percussiveness on our emotions. In a quest towards ecologically valid results, 32 participants listened to 16 pop and 16 rock songs while conducting an office task. They rated experienced arousal, valence, and tension, while skin conductance and cardiovascular responses were recorded. An increase in tempo was found to lead to an increase in reported arousal and tension and a decrease in heart rate variability. More arousal was reported during minor than major mode songs. Level and frequency of skin conductance responses increased with an increase in percussiveness. Physiological responses revealed patterns that might not have been revealed by self-report. Interaction effects further suggest that musical characteristics interplay in modulating emotions. So, tempo, mode, and percussiveness indeed modulate our emotions and, consequently, can be used to direct emotions. Music presentation revealed subtly different results in a laboratory setting, where music was altered with breaks, from those in a more ecologically valid setting where continuous music was presented. All in all, this enhances our understanding of the influence of music on emotions and creates opportunities seamlessly to tap into listeners’ emotional state through their physiological responses.

Live High + Train Low: Thinking in Terms of an Optimal Hypoxic Dose

2007 ◽  
Vol 2 (3) ◽  
pp. 223-238 ◽  
Author(s):  
Randall L. Wilber
Keyword(s):  
Sea Level ◽  
Physiological Responses ◽  
Hypoxic Exposure ◽  
Altitude Training ◽  
Subsequent Increase ◽  
Endogenous Erythropoietin ◽  
Altitude Acclimatization ◽  
Performance Effects ◽  
Key Issues ◽  
Level Performance

“Live high-train low” (LH+TL) altitude training allows athletes to “live high” for the purpose of facilitating altitude acclimatization, as characterized by a significant and sustained increase in endogenous erythropoietin and subsequent increase in erythrocyte volume, while simultaneously enabling them to “train low” for the purpose of replicating sea-level training intensity and oxygen flux, thereby inducing beneficial metabolic and neuromuscular adaptations. In addition to natural/terrestrial LH+TL, several simulated LH+TL devices have been developed including nitrogen apartments, hypoxic tents, and hypoxicator devices. One of the key issues regarding the practical application of LH+TL is what the optimal hypoxic dose is that is needed to facilitate altitude acclimatization and produce the expected beneficial physiological responses and sea-level performance effects. The purpose of this review is to examine this issue from a research-based and applied perspective by addressing the following questions: What is the optimal altitude at which to live, how many days are required at altitude, and how many hours per day are required? It appears that for athletes to derive the hematological benefits of LH+TL while using natural/terrestrial altitude, they need to live at an elevation of 2000 to 2500 m for >4 wk for >22 h/d. For athletes using LH+TL in a simulated altitude environment, fewer hours (12-16 h) of hypoxic exposure might be necessary, but a higher elevation (2500 to 3000 m) is required to achieve similar physiological responses.

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