The variation of the 5-hydroxytryptamine system between chronic unpredictable mild stress rats and chronic fatigue syndrome rats induced by forced treadmill running

Abstract:

The aim of this study was to observe the variation in the 5-hydroxytryptamine (5-HT) system between a chronic unpredictable mild stress (CUMS) model and a chronic fatigue syndrome (CFS) model. The total distance, the crossing pieces, and rearing times in the open-field test of the CUMS group and the CFS group were all less than those of the control group to different degrees.

The concentrations of tryptophan, 5-HT, and 5-HIAA of the CUMS group were obviously lower than those of the control group. In the CFS model, the concentrations of tryptophan, 5-HT, and 5-HIAA were obviously higher than those of the control group. The expressions of tryptophan hydroxylase-2 (TPH-2) and 5-HT1A receptor in protein level and mRNA level were also different among the three groups. The expressions of TPH-2 and 5-HT1A were higher in the CFS group than in the CUMS group. The expressions of TPH-2 and 5-HT1A receptor were lower in the CUMS group than in the control group. We can find that in different situations of mood disorders, the variation of 5-HT system may also be opposite.

Source: Cao Y, Li Q. The variation of the 5-hydroxytryptamine system between chronic unpredictable mild stress rats and chronic fatigue syndrome rats induced by forced treadmill running. Neuroreport. 2017 May 12. doi: 10.1097/WNR.0000000000000797. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28505018

Brain 5-HT1A receptor binding in chronic fatigue syndrome measured using positron emission tomography and [11C]WAY-100635

Abstract:

BACKGROUND: Research from neuroendocrine challenge and other indirect studies has suggested increased central 5-HT function in chronic fatigue syndrome (CFS) and increased 5-HT1A receptor sensitivity. We assessed brain 5-HT1A receptor binding potential directly using the specific radioligand [11C]WAY-100635 and positron emission tomography (PET).

METHODS: We selected 10 patients from a tertiary referral clinic who fulfilled the CDC consensus criteria for CFS. To assemble a homogenous group and avoid confounding effects, we enrolled only subjects who were completely medication-free and did not have current comorbid psychiatric illness. We also scanned 10 healthy control subjects.

RESULTS: There was a widespread reduction in 5-HT1A receptor binding potential in CFS relative to control subjects. This was particularly marked in the hippocampus bilaterally, where a 23% reduction was observed.

CONCLUSIONS: There is evidence of decreased 5-HT1A receptor number or affinity in CFS. This may be a primary feature of CFS, related to the underlying pathophysiology, or a finding secondary to other processes, such as previous depression, other biological changes or the behavioral consequences of CFS.

 

Source: Cleare AJ, Messa C, Rabiner EA, Grasby PM. Brain 5-HT1A receptor binding in chronic fatigue syndrome measured using positron emission tomography and [11C]WAY-100635. Biol Psychiatry. 2005 Feb 1;57(3):239-46. http://www.ncbi.nlm.nih.gov/pubmed/15691524

 

Increased prolactin response to buspirone in chronic fatigue syndrome

Abstract:

We studied the endocrine and subjective responses that followed acute administration of the 5-HT1A receptor agonist buspirone (0.5 mg/kg orally) in 11 male patients with chronic fatigue syndrome (CFS) and a group of matched healthy controls.

Patients with CFS had significantly higher plasma prolactin concentrations and experienced more nausea in response to buspirone than did controls. However, the growth hormone response to buspirone did not distinguish CFS patients from controls.

Our data question whether the enhancement of buspirone-induced prolactin release in CFS is a consequence of increased sensitivity of post-synaptic 5-HT1A receptors. It is possible that the increased prolactin response to buspirone in CFS could reflect changes in dopamine function.

 

Source: Sharpe M, Clements A, Hawton K, Young AH, Sargent P, Cowen PJ. Increased prolactin response to buspirone in chronic fatigue syndrome. J Affect Disord. 1996 Nov 4;41(1):71-6. http://www.ncbi.nlm.nih.gov/pubmed/8938208