BACKGROUND: Studies have shown that bariatric surgery, such as sleeve gastrectomy (SG), has an adverse effect on bone, including decreased bone mineral density (BMD) and bone metabolism. Peripheral 5-hydroxytryptamine (5-HT) has an adverse regulatory effect on bone formation. Here, we assessed changes in bone metabolism and whether 5-HT is involved in the effect of SG on bone metabolism.

MATERIAL AND METHODS: A rat model of obesity was established using Wistar rats. After successful modeling, rats were randomly assigned to 2 groups – the SG group and the Sham group – with 10 rats in each group. We then performed sleeve gastrectomy or sham operation. Bone metabolic markers and BMD of rats were measured at 2 and 16 weeks after the operation and the level of 5-HT in serum was determined. Rats were killed at 16 weeks after the operation, and bones of the hind limbs were harvested to measure 5-HT by immunofluorescence.

RESULTS: BMD was decreased and bone metabolism demonstrated a trend of bone destruction in the rats after SG. A significantly increasing trend in the level of serum 5-HT was found, and bone immunofluorescence showed increased expression of 5-HT.

CONCLUSIONS: BMD was decrease and bone metabolism demonstrated a trend of bone destruction after SG. SG can affect the level of 5-HT in serum or bone tissue and the 5-HT may be involved in the process through which SG affects bone metabolism.

Keywords: Bone Density, Gastrectomy, Metabolism, Receptor, Serotonin, 5-HT1A, Bariatric Surgery, Diabetes Mellitus, Experimental, Diabetes Mellitus, Type 2, Obesity, Obesity, Morbid, Serotonin, Weight Loss