The effects of hypothyroidism on the functional integrity of the hypothalamic-pituitary-adrenal (HPA) axis were investigated in adult male rats. HPA axis function was examined in vivo in sham-thyroidectomized male Sprague-Dawley rats or in thyroidectomized rats for 7 (short-term hypothyroidism) or 60 (long-term hypothyroidism) days. Peripheral ACTH and corticosterone responses to insulin-induced hypoglycemia and interleukin (IL)-1α stimulation were used to indirectly assess the hypothalamic CRH neuron. Hypothyroidism resulted in exaggerated ACTH responses to both hypoglycemic stress and IL-1α administration. The adrenal cortex of hypothyroid animals showed a significant reduction in adrenal reserves, as assessed by its response to low-dose ACTH, following suppression of the HPA axis with dexamethasone. Hypothyroid rats were also associated with significant decreases in cerebrospinal fluid corticosterone concentrations and decreased adrenal weights. The findings suggest that experimentally induced hypothyroidism is associated with a mild, yet significant, adrenal insufficiency, which involves abnormalities in all components of the HPA axis.
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http://dx.doi.org/10.3275/8454 | DOI Listing |
Neurosci Biobehav Rev
January 2025
Department of Psychiatry and Psychotherapy, Philipps University Marburg, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behaviour, Philipps University Marburg, Hans-Meerwein-Str. 6, 35032 Marburg, Germany. Electronic address:
Recurrent psychosocial stress poses a significant health challenge, prompting research into mechanisms of successful adaptation. Physiological habituation, defined as decreased reactivity to repeated stressors, is pivotal in protecting the organism from allostatic load. Here, we systematically review and meta-analyze data from studies investigating the capacity of central stress systems to habituate when repeatedly exposed to a standardized psychosocial stressor, the Trier Social Stress Test (k=47).
View Article and Find Full Text PDFPsychoneuroendocrinology
December 2024
University of California, Irvine, Department of Psychological Science, Irvine, CA, USA; University of California Los Angeles, Cousins Center for Psychoneuroimmunology, Los Angeles, CA, USA.
Background: Acute psychosocial stress activates the hypothalamic-pituitary-adrenal (HPA) axis and triggers the release of cortisol, a commonly used biomarker of stress reactivity. Yet only 25 % of studies have reported a correlation between cortisol and affective responses to stress. This study aimed to examine whether cortisol reactivity following an acute psychosocial stressor in the laboratory correlated with concurrent positive and negative affect in adolescents, and whether early life adversity (ELA) moderated this relationship.
View Article and Find Full Text PDFCurr Cardiol Rev
January 2025
Division of Applied Biomedical Science and Biotechnology, School of Health Sciences, IMU University, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.
Cardiovascular Disease [CVD], the leading cause of death globally, poses a significant burden on the healthcare sector. Its association with stress and Cushing's Syndrome has driven cortisol, the 'stress hormone,' to be a potential candidate in determining CVD risk. Cortisol synthesis and release through the hypothalamic-pituitary-adrenal [HPA] axis are regulated by several hormones and receptors involved in the pathological cascade towards CVD.
View Article and Find Full Text PDFCurr Vasc Pharmacol
January 2025
Department of Cardiology, Ippokrateio University Hospital, Athens, Greece.
Introduction/objective: Emotional, mental, or psychological distress, defined as increased symptoms of depression, anxiety, and/or stress, is common in patients with chronic diseases, such as cardiovascular (CV) disease (CVD).
Methods: Literature was reviewed regarding data from studies and meta-analyses examining the impact of emotional stress on the occurrence and outcome of several CVDs (coronary disease, heart failure, hypertension, arrhythmias, stroke). These influences' pathophysiology and clinical spectrum are detailed, tabulated, and pictorially illustrated.
Psychopharmacology (Berl)
January 2025
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Canada.
Rationale: Clinical literature indicates there may be a therapeutic use of cannabidiol (CBD) for stress-related disorders. Preclinical literature remains conflicted regarding the underlying neurobehavioral mechanisms, reporting mixed effects of CBD (increased, decreased, or no effect) on anxiety- and fear-related behaviors. Preclinical data demonstrated that CBD modulates hypothalamus-pituitary-adrenal (HPA) axis gene expression; it is unknown whether CBD changes HPA axis responsivity and how this relates to altered behavior.
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