Study The Effect Of Total Gastrectomy On Blood Pressure In Spontaneously Hypertensive Rats

ObjectiveIn this study, we establish the models of total gastrectomy with different surgical reconstruction(Roux-en-Y, Billroth ?) and Duodeno-jejunal Bypass on Spontaneously hypertensive rats(SHR).The different time points of blood pressure, urine volume, urinary sodium and fasting serum ghrelin were measured, which may be to evaluate the effect of total gastrectomy on blood pressure in SHR.MethodsForty SHR were randomly divided into four groups: Roux-en-Y(RY) group, Billroth ?(B-1) group, Duodeno-jejunal Bypass group(DJB) and sham operation group(SO). The surgery of Roux-en-Y were taken on SHR in RY group, the surgery of Billroth ? taken on SHR in B-1 group, the surgery of Duodeno-jejunal Bypass taken on SHR in DJB group, the surgery of sham operation taken on SHR in SO group. The body weight of four groups was measured before operation and 1, 2, 4, 8, 12, 24 weeks after operation. The blood pressure of four groups was done before operation and 4, 8, 12, 24 weeks after operation. The changes of urine volume, urinary sodium and ghrelin levels in four groups were observed in before operation and 12, 24 weeks after operation. The analysis was conducted on body weight, blood pressure, urine volume/body weight, urinary sodium/body weight, and fasting serum ghrelin.Results1. Body weightCompared to pre-operation, the body weight were decreased at the first week after the operation in four groups, but there was no significant difference. The body weight were continuing significantly decline from the second week to twenty fourth week after operation in B-1 group when compared with pre-operation. The body weight began to rise at the second week and was close to preoperative level at the eighth week in RY group, however, it began todrop after 8 week. It was significantly decline in RY and B-1 groups when compared to SO group after the second week(P<0.05).It was significantly increased in DJB group and SO group when compared with pre-operation, but there was no significant difference between DJB group and SO group.2. Blood pressureThe blood pressure in RY and B-1 group was decreased when compared to pre-operation at the fourth week after operation, but there was no significant difference. The blood pressure began to descend at the eighth week after operation when compared to pre-operation. It was significantly lower in RY and B-1 group when compared to SO group at the eighth,twelfth and twenty fourth week(P<0.05). There was no significant difference between RY group and B-1group. It was higher DJB group and SO group when compared to pre-operation,meanwhile, there was no significant difference between DJB group and SO group.3. Urine volume/body weightThe Urine volume/body weight in RY and B-1 group was increased when compared to pre-operation at the fourth, twelfth and twenty fourth week after operation. It was significantly higher in RY and B-1 group when compared to SO group at these times(P<0.05).There was no significant difference in DJB group and SO group when compared to pre-operation at these times, the same as between DJB group and SO group.4. Urinary sodium/body weightThe urinary sodium /body weight in RY and B-1 group was higher when compared to pre-operation at the fourth, twelfth and twenty fourth week after operation. It was significantly higher in RY and B-1 group when compared to SO group at these times(P<0.05).There was no significant difference in DJB group and SO group when compared to pre-operation at these times, the same as between DJB group and SO group.5. Fasting serum ghrelinThe fasting serum ghrelin of serum in RY and B-1 group was reduced when compared to pre-operation at the fourth, twelfth and twenty fourth week after operation. It was significantly reduced in RY and B-1 group when compared to SO group at these times(P<0.05).There was no significant difference in DJB group and SO group when compared topre-operation at these times, the same as between DJB group and SO group.Conclusions1. Gastrectomy but not the bypass can lower blood pressure in SHR rats, which is associated with the lack of stomach rather than RY bypass.2. The amount of urine volume and urine sodium after total gastrectomy are increased in SHR rats, which is involved in the regulation of blood pressure and improve it on post-operation.3. The serum ghrelin were decline after total gastrectomy, which is related to the changes for blood pressure.