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Ovariectomy reduces Visceral Hypersensitivity in Female Serotonin Transporter (SERT) Knockout (KO) Rats
Author(s) -
Fried David E.,
Galligan James J
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.945.1
Subject(s) - medicine , endocrinology , serotonin transporter , serotonin , ovariectomized rat , irritable bowel syndrome , estrous cycle , hormone , receptor
Visceral hypersensitivity (VH) is a symptom in irritable bowel syndrome (IBS), particularly in women and symptom severity varies over the menstrual cycle. Disrupted serotonin signaling, including reduced SERT expression, occurs in some IBS patients. We studied VH in male and female SERT KO and wild type (WT) rats to determine if SERT deficiency and the estrous cycle were associated with VH. Methods VH was measured using the abdominal electromyographic visceromotor response (VMR) to colorectal balloon distention (CRD). We also assessed somatic hypersensitivity using the hot plate test. Ovariectomized (OVX) SERT KO and WT rats were used to investigate the effects of gonadal hormones on VH. Results The VMR to CRD was increased in female but not male SERT KO rats (P<0.05); the maximum response occurred during proestrus. The VMR was greater in female SERT KO vs. female WT rats. OVX reduced VH in female SERT KO rats (P<0.05). There were no differences in somatic thermal sensitivity between female WT and SERT KO rats. Conclusions There is an interaction between increased serotonin availability (as occurs in SERT KO rats) and female gonadal hormones that results in VH. This mimics symptoms occurring in female IBS patients. The SERT KO rat may be a useful model for mechanistic studies of interactions between sex, serotonin and visceral sensation.