Neuroendocrine and blood pressure responses to rectal distensions in individuals with high and low visceral pain sensitivity.
BACKGROUND
The mechanisms of interindividual variations in visceral pain sensitivity remain poorly understood. We characterized the neuroendocrine responses to rectal distensions in healthy individuals with high vs. low rectal pain sensitivity.


METHODS
Rectal sensory and pain thresholds were determined, and a series of random painful distensions was carried out. Eighteen subjects were stratified into groups with a low rectal pain threshold ("High Sensitivity" group) vs. a high rectal pain threshold ("Low Sensitivity" group) by median split, and were compared with regard to adrenocorticotropic hormone (ACTH) and cortisol, cardiovascular, and emotional responses.


RESULTS
Distensions led to an anticipatory stress response, reflected by elevated baseline anxiety, and increased baseline ACTH and cortisol in both groups. In response to distensions, the "Low Sensitivity" group showed significantly greater ACTH and cortisol concentrations analysis of variance (ANOVA time x group for ACTH: p<.05; for cortisol: p<.01), and elevated diastolic blood pressures (BP) (ANOVA group: p<.01) when compared to the "High Sensitivity" group.


CONCLUSIONS
Painful rectal distensions are associated with a pronounced anticipatory stress response, reflected by elevated anxiety and elevated stress hormones. Individuals with high rectal pain sensitivity differ from those with low pain sensitivity in distension-induced hormonal and blood pressure responses, suggesting that neuroendocrine responses may be relevant to the pathophysiology of visceral hyperalgesia.
Elsenbruch
S
S
Department of Medical Psychology, University Hospital of Essen Medical School, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany. sigrid.elsenbruch@uk-essen.de
Haag
S
S
Lucas
A
A
Riemenschneider
N
N
Pietsch
A
A
Gerken
G
G
Heijnen
C J
CJ
Schedlowski
M
M
Holtmann
G
G
D015746:Abdominal Pain / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D000223:Adaptation, Psychological / Q000502:physiology; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D000704:Analysis of Variance; D001007:Anxiety / Q000209:etiology / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D004106:Dilatation; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007206:Individuality; D008297:Male; D017288:Pain Threshold / Q000502:physiology* / Q000523:psychology; D010913:Pituitary-Adrenal System / Q000502:physiology; D012007:Rectum / Q000502:physiology* / Q000503:physiopathology; D012016:Reference Values; D013315:Stress, Psychological
D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone