Tag: thermoregulation

Homeostatic disturbance of thermoregulatory functions in rats with chronic fatigue

Abstract:

Chronic fatigue syndrome (CFS) is characterized by long-lasting fatigue, and a range of symptoms, and is involved in homeostasis disruption. CFS patients frequently complain of low grade fever or chill even under normal body temperature indicating that thermosensory or thermoregulatory functions might be disturbed in CFS. However, little is known about the detailed mechanisms. To elucidate whether and how thermoregulatory function was altered during the development of chronic fatigue, we investigated temporal changes in body temperature with advance of fatigue accumulation in a chronic fatigue rat model using a wireless transponder.

Our findings demonstrated that the body temperature was adaptively increased in response to fatigue loading in the early phase, but unable to retain in the late phase. The tail heat dissipation was often observed and the frequency of tail heat dissipation gradually increased initially, then decreased. In the late phase of fatigue loading, the body temperature for the tail heat dissipation phase decreased to a value lower than that for the non-dissipation phase. These results suggest that adaptive changes in thermoregulatory function occurred with fatigue progression, but this system might be disrupted by long-lasting fatigue, which may underlie the mechanism of fatigue chronification.

Copyright © 2020. Published by Elsevier B.V.

Source: Li D, Hu D, Shigeta M, Ochi Y, Watanabe Y, Li F, Cui Y. Homeostatic disturbance of thermoregulatory functions in rats with chronic fatigue. Neurosci Res. 2020 Apr 30. pii: S0168-0102(20)30157-7. doi: 10.1016/j.neures.2020.04.005. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/32361157

 

Abnormal thermoregulatory responses in adolescents with chronic fatigue syndrome: relation to clinical symptoms

Abstract:

OBJECTIVES: Chronic fatigue syndrome is a common and disabling disease of unknown etiology. Accumulating evidence indicates dysfunction of the autonomic nervous system. To further explore the pathophysiology of chronic fatigue syndrome, we investigated thermoregulatory responses dependent on catecholaminergic effector systems in adolescent patients with chronic fatigue syndrome.

PATIENTS AND METHODS: A consecutive sample of 15 patients with chronic fatigue syndrome aged 12 to 18 years and a volunteer sample of 57 healthy control subjects of equal gender and age distribution were included. Plasma catecholamines and metanephrines were measured before and after strong cooling of 1 hand. Acral skin blood flow, tympanic temperature, heart rate, and mean blood pressure were measured during moderate cooling of 1 hand. In addition, clinical symptoms indicative of thermoregulatory disturbances were recorded.

RESULTS: Patients with chronic fatigue syndrome reported significantly more shivering, sweating, sudden change of skin color, and feeling unusually warm. At baseline, patients with chronic fatigue syndrome had higher levels of norepinephrine, heart rate, epinephrine, and tympanic temperature than control subjects. During cooling of 1 hand, acral skin blood flow was less reduced, vasoconstrictor events occurred at lower temperatures, and tympanic temperature decreased more in patients with chronic fatigue syndrome compared with control subjects. Catecholamines increased and metanephrines decreased similarly in the 2 groups.

CONCLUSIONS: Adolescent patients with chronic fatigue syndrome have abnormal catecholaminergic-dependent thermoregulatory responses both at rest and during local skin cooling, supporting a hypothesis of sympathetic dysfunction and possibly explaining important clinical symptoms.

 

Source: Wyller VB, Godang K, Mørkrid L, Saul JP, Thaulow E, Walløe L. Abnormal thermoregulatory responses in adolescents with chronic fatigue syndrome: relation to clinical symptoms. Pediatrics. 2007 Jul;120(1):e129-37. https://www.ncbi.nlm.nih.gov/pubmed/17606539