scholarly journals 5-HT Receptors and Temperature Homeostasis

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1914
Author(s):  
Irina P. Voronova
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Heat Production ◽  
Simultaneous Increase ◽  
Peripheral Blood Flow ◽  
Natural Conditions ◽  
Physiological Mechanisms ◽  
Physiological Processes ◽  
Temperature Homeostasis ◽  
Shivering Thermogenesis

The present review summarizes the data concerning the influence of serotonin (5-HT) receptors on body temperature in warm-blooded animals and on processes associated with its maintenance. This review includes the most important part of investigations from the first studies to the latest ones. The established results on the pharmacological activation of 5-HT1A, 5-HT3, 5-HT7 and 5-HT2 receptor types are discussed. Such activation of the first 3 type of receptors causes a decrease in body temperature, whereas the 5-HT2 activation causes its increase. Physiological mechanisms leading to changes in body temperature as a result of 5-HT receptors’ activation are discussed. In case of 5-HT1A receptor, they include an inhibition of shivering and non-shivering thermogenesis, as well simultaneous increase of peripheral blood flow, i.e., the processes of heat production and heat loss. The physiological processes mediated by 5-HT2 receptor are opposite to those of the 5-HT1A receptor. Mechanisms of 5-HT3 and 5-HT7 receptor participation in these processes are yet to be studied in more detail. Some facts indicating that in natural conditions, without pharmacological impact, these 5-HT receptors are important links in the system of temperature homeostasis, are also discussed.

Cell thermoregulation and origin of homeothermic animals

2019 ◽  
Vol 1 (1) ◽  
pp. 10-13
Author(s):  
Abyt Ibraimov
Keyword(s):  
Reaction Rates ◽  
The Body ◽  
Necessary Condition ◽  
Internal Temperature ◽  
Physiological Mechanisms ◽  
Physiological Processes ◽  
Material Basis ◽  
External Sources ◽  
Temperature Homeostasis ◽  
Central Organ

Temperature has a fundamental influence in all chemical and biochemical reactions. It influences reaction rates, equilibrium amounts, viscosity, solubility, molecular arrangements and numeric other parameters. Temperature is important for all physiological processes. Maintaining the relative constancy of the internal temperature (temperature homeostasis) is a necessary condition for normal life. Some living beings maintain temperature homeostasis in the body due to external sources of energy (poikilothermy), others due to the energy of food consumption (homeothermy). However, it is unknown the origin of homeothermic organisms. Despite the fundamental similarity of the mechanisms of the central organ-based physiological thermoregulation, even among the higher vertebrates exists poikilothermy and homeothermy animals. It is assumed that homeothermy is not the result of the evolution of physiological mechanisms of thermoregulation. Homeothermy is the result of the evolution of non-coding DNAs in the genome, some of which formed the so-called chromosomal heterochromatin regions (HRs). Chromosomal HRs constitutes the material basis of cell thermoregulation, which is responsible for the removal of excess thermal energy from the nucleus into the cytoplasm. Homeothermic organisms, unlike poikilotherms capable of faster and more efficient leveling of temperature difference between the nucleus and the cytoplasm with all the ensuing consequences.

Afterdrop of body temperature during rewarming: an alternative explanation

1986 ◽  
Vol 60 (2) ◽  
pp. 385-390 ◽  
Author(s):  
P. Webb
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Peripheral Blood ◽  
Alternative Explanation ◽  
Mild Hypothermia ◽  
Physical Models ◽  
Peripheral Blood Flow ◽  
Body Temperatures ◽  
Cold Blood ◽  
Deep Body

Afterdrop, the continued fall of deep body temperatures during rewarming after hypothermia, is thought to endanger the heart by further cooling from cold blood presumed to be returning from the periphery. However, afterdrop is not always observed, depending on the circumstances. To explore this phenomenon, mild hypothermia was induced quantitatively with a suit calorimeter, using several patterns of cooling and rewarming. When cooling was rapid and followed immediately by rewarming, there were typical afterdrops in the temperatures measured in the rectum, auditory canal, and esophagus. However, when rewarming was delayed, or when cooling had been slow and prolonged, afterdrop was not seen. Afterdrops were then observed in two physical models that had no circulation: a bag of gelatin and a leg of beef. Central layers continued to give up heat as long as the surrounding layer was cooler. These results, together with recent findings by others that peripheral blood flow is low until afterdrop is complete, make this circulatory explanation of afterdrop improbable. Alternatively, afterdrop can be explained by the way heat moves through a mass of tissue.

Postnatal changes in regional blood flow during cold-induced shivering in sow-reared piglets

1999 ◽  
Vol 77 (6) ◽  
pp. 414-421 ◽  
Author(s):  
Gaëlle Lossec ◽  
Claude Duchamp ◽  
Yves Lebreton ◽  
Patrick Herpin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Heat Production ◽  
Cold Exposure ◽  
Cardiovascular Response ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Cold Challenge ◽  
Shivering Thermogenesis

To determine whether newborn pigs are able to display adequate cardiovascular adjustments favouring shivering thermogenesis in skeletal muscles soon after birth, regional blood flow and fractional distribution of cardiac output were determined in 1-day-old (n = 6) and 5-day-old (n = 6) conscious piglets at thermal neutrality and during cold exposure, using coloured microspheres. Five-day-old piglets stayed with the sow before the experiment. The cold challenge was designed to induce a similar increase (~+90%) in heat production at both ages. Skeletal muscle blood flow increased with both age (p < 0.05) and cold exposure (p < 0.001), with the effect of cold being more pronounced in 5-day-old piglets than in 1-day-old piglets (+60%, p < 0.05). The difference between individual muscles increased with age, with fractional blood flow being 41% higher in rhomboideus than in longissimus thoracis muscle during cold exposure in 5-day-old piglets (p < 0.05). Cardiac output was similar at both ages and increased by 23% in the cold (p < 0.001). At 1 day of age, there was no redistribution of cardiac output among the internal organs during the cold challenge, while at 5 days of age, the increase in muscle fractional blood flow was associated with a reduction (p < 0.05) in the fraction of cardiac output reaching the skin (-24%), the small intestine (-21%), and the liver (-20%). In conclusion, these results suggest that there is a rapid postnatal improvement of cardiovascular adjustments favouring blood perfusion and probably heat production during cold-induced shivering in the most oxidative muscles studied. This cardiovascular response may play a role in the postnatal enhancement of thermoregulation in piglets.Key words: skeletal muscle, blood distribution, shivering thermogenesis, piglet, age.

Learning the regulation of peripheral blood flow.

1999 ◽  
Vol 277 (6) ◽  
pp. S164 ◽  
Author(s):  
H V Sparks
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Local Control ◽  
Skin Blood Flow ◽  
Special Functions ◽  
Building Blocks ◽  
Peripheral Circulation ◽  
Peripheral Blood Flow ◽  
Control Regulation ◽  
Neurohumoral Control

Students can learn a great deal about the peripheral circulation when teaching is based on five building blocks: hemodynamic principles, neurohumoral control, and three elements of local control of blood flow (metabolic, myogenic, and paracrine). Study of a particular special circulation starts with the application of these building blocks in the context of the function of that tissue. For example, control of skin blood flow is largely concerned with regulation of body temperature (neurohumoral control) and the response to injury (paracrine control). Regulation of coronary blood flow is almost entirely a matter of meeting the metabolic needs of the myocardium (metabolic control). By mixing and matching the five building blocks and keeping in mind the special functions of a particular tissue, students can master the peripheral circulation efficiently.

Temperature regulation of Eskimos, Indians, and Caucasians in a bath calorimeter

1963 ◽  
Vol 18 (2) ◽  
pp. 378-382 ◽  
Author(s):  
Frederick A. Milan ◽  
John P. Hannon ◽  
Eugene Evonuk
Keyword(s):  
Blood Flow ◽  
Body Fat ◽  
Rectal Temperature ◽  
Heat Production ◽  
Temperature Gradients ◽  
The Other ◽  
Whole Body ◽  
Peripheral Blood Flow ◽  
Skin Fold ◽  
Tissue Insulation

Eighteen men: six Alaskan Eskimos, six Arctic Athapascan Indians, and six Caucasian U. S. soldiers were immersed serially in a bath calorimeter where the rates of heat production and loss were measured during whole-body exposure to water temperatures of 35, 33, and 30.5 C. At each of these temperatures the Eskimos exhibited the highest rates of heat production and loss, followed by the Indians and Caucasians in decreasing order. Duplicate basal metabolic rate measurements averaged 46 kcal/hr m2 in the Eskimos, 42.5 kcal/hr m2 in the Indians, and about 37 kcal/hr m2 in the Caucasians. Body fat percentages calculated by the skin-fold method were: Eskimos, 6.6%; Indians, 12.3%; and Caucasians, 15.6%. Calculations showed the Eskimos had the lowest tissue insulation followed, respectively, by the Indians and Caucasians. Calculations showed the lower insulation in the Eskimos was independent of their lack of body fat and probably reflected a greater peripheral blood flow. Since the rectal temperature decrements during immersion were the same in all three groups, it was concluded that the surface temperature gradients extended more deeply in the Eskimos than in the other two groups. Hence, they could be described as having smaller “cores” and larger “shells” than either the Indians or the Caucasians. Submitted on August 27, 1962d

Ultrasound features of peripheral angiodistonic syndrome of the upper extremities in vibration disease

2020 ◽  
Vol 60 (11) ◽  
pp. 815-817
Author(s):  
Nadezhda I. Kuprina ◽  
Ekaterina V. Ulanovskaya ◽  
Olga A. Kochetova
Keyword(s):  
Blood Flow ◽  
Heart Defects ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Ulnar Artery ◽  
Upper Extremities ◽  
Disease Stage ◽  
Peripheral Blood Flow ◽  
Pronounced Increase ◽  
Vibration Disease

Introduction. Vibration disease (VD) is an example of the most common pathology due to the systematic exposure of the worker to intense vibration with sufficient work experience, the main manifestation of which is peripheral angiodystonic syndrome. The aim of study was to learn the features of peripheral blood flow in the arteries of the forearm in vibration disease using the ultrasound method. Materials and methods. The radial and ulnar arteries in patients with vibration disease were examined by ultrasound in B- and PW-mode. These materials present the results of an ultrasound assessment of the speed indicators of the main arteries of the forearm in vibration disease stages 1 and 2. The selection criteria for patients in the study ware the presence of pronounced clinical manifestations of angiodystonic syndrome in vibration disease, confirmed by instrumental research methods and data on the sanitary and hygienic characteristics of working conditions, the absence of cardiovascular chronic diseases (ischemic heart disease, heart defects, rhythm and conduction disturbances), rheumatic, oncological, infectious diseases, osteo-traumatic changes in the upper extremities. Results. The groups of patients with the established diagnosis of vibration disease of 1 and 2 degrees were studied. With vibration disease stage 1 a decrease in the pulse velocity of blood flow was observed in isolation on the ulnar artery and an increase in peripheral resistance (pulsation index and resistance index) in the radial and ulnar arteries symmetrically on both upper extremities. The second stage of vibration disease differed from the first by a more significant decrease in speed indicators both on the ulnar and radial arteries on both sides, symmetrically in combination with a more pronounced increase in peripheral resistance indicators on both main arteries of the forearm (pulsation index and resistance index). The revealed changes were determined with the same frequency in men and women. Conclusions. A significant decrease in speed indicators on the ulnar artery and an increase in peripheral resistance indicators are detected already at the initial stages of vibration disease. Thus, the method of ultrasound examination of the main arteries of the middle caliber of the upper extremities is currently the only available and objective method for examining the vascular system in vibration disease.

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