AIM:The present study was aimed to investigate thedevelopmental patterns of growth hormone receptor (GHr)and somatostatin (SS) mRNA expression in porcine gastrictissue and its relationship with gastric growth and gastricfunctional development.METHODS:Erhualian and Large White boars were selectedrandomly and sampled at birth (DO),3,20,30,90,120 and180 days of age respectively,meanwhile the bodyweight andgastric weight were recorded.The single tube semi-quantitative RT-PCR was applied in this experiment toinvestigate the developmental patterns of gastric GHr and SSmRNA expression,the correlations between the patterns ofmRNA expression and the relative gastric weight (ratio ofgastric weight to bodyweight) and the pepsin contents ingastric mucous membrane were analyzed.In order to furtherelucidate the effect of GH on gastric function,the primarycultures of gastric fundic mucosal cells were treated with 2ng/ml,20 ng/ml and 200 ng/ml of rpGH for 18 hrs respectively,and the pepsin contents in culture medium were measured.RESULTS:The expression of GHr mRNA was high at birth,followed by a significant decrease at 3 days of age (D3) inboth breeds.In Large White boars,the expression of GHrmRNA reached a peak at D90 and remained a plateauafterward.In Erhualian pigs,however,a slight yet significantincrease occurred at D30 reaching a level that was keptconstant thereafter.From birth to D30,the expression of GHrmRNA in gastric tissue was higher in Erhualian boars thanthat in Large White boars,but from D90 to D180,the higherexpression of GHr mRNA was found in Large White boars.The gastric GHr mRNA expression was significantly correlatedwith the relative gastric weight (r=0.541,P<0.05) and pepsincontent in gastric mucosa (r=0.625,P<0.05) respectively.The gastric SS mRNA expression was high at birth(Erhualian 1.59,Large White 0.80),but dropped significantlyat D3 (Erhualian 0.95,Large White 0.19,P<0.05),a stepwiseincrease was followed thereafter until a peak at D30(Erhualian 1.71,Large White 0.95) In general,Erhualianpigs expressed higher levels of SS mRNA in gastric tissue ascompared with Large White pigs at the same age (P<0.05).No significant correlations between SS mRNA and relativegastric weight or pepsin content were found. In vitro,2 ng/ml of rpGH elicited significant increase inpepsin secretion from primary cultures of gastric mucosalcells (P<0.05),and no responses were observed at 20 ng/ml and 200 ng/ml.CONCLUSION:The results suggested that:1,GHr and SSmRNA in porcine stomach are expressed according to strainspecific developmental patterns;2,GH acts directly at thegastric tissue and regulates the structural and functionalgrowth of stomach. AIM: The present study was aimed to investigate the developmental patterns of growth hormone receptor (GHr) and somatostatin (SS) mRNA expression in porcine gastrictase and its relationship with gastric growth and gastric functional development. METHODS: Erhualian and Large White boars were selected and exactly sampled and at birth (DO), 3,20,30,90,120 and 180 days of age respectively, meanwhile the bodyweight andgastric weight were recorded in single single-dose RT-PCR was applied in this experiment to investigate the developmental patterns of gastric GHr and SSmRNA expression , the correlations between the patterns of mRNA expression and the relative gastric weight (ratio of gastric weight to bodyweight) and the pepsin contents ingastric mucous membrane were analyzed.In order to furtherelucidate the effect of GH on gastric function, the primary cultures of gastric fundic mucosal cells were treated with 2 ng / ml, 20 ng / ml and 200 ng / ml of rpGH for 18 hrs respectively, and the pepsin contents in The expression of GHr mRNA was a high at birth, followed by a significant decrease at 3 days of age (D3) inboth breeds. Large White boars, the expression of GHr mRNA reached a peak at D90 and remained a Plateau afterward. In Erhualian pigs, however, a slight yet significant increase occurred at D30 reaching a level that was keptconstant thereafter. From birth to D30, the expression of GHr mRNA in gastric tissue was higher in Erhualian boars thanthat in Large White boars, but from D90 to D180, the higherexpression of GHr mRNA was found in Large White boars.The gastric GHr mRNA expression was significantly correlated with the relative gastric weight (r = 0.541, P <0.05) and pepsincontent in gastric mucosa (r = 0.625, P <0.05) The gastric SS mRNA expression was high at birth (Erhualian 1.59, Large White 0.80), but dropped significantly D3 (Erhualian 0.95, Large White 0.19, P <0.05), a stepwise increase was followed thereafter until a peak at D30 (Erhualian 1.71, Large White 0.95) In general, Erhualianpigs expressed higher levels of SS mRNA in gastric tissue ascompared with Large White pigs at the same age (P <0.05) .No significant correlations between SS mRNA and relative gastric weight or pepsin content were found. In vitro, 2 ng / ml of rpGH elicited significant increase inpepsin secretion from primary cultures of gastric mucosal cells (P <0.05), and no responses were observed at 20 ng / ml and 200 ng / ml. CONCLUSION: The results suggested that: 1, GHr and SS mRNAs in porcine stomach are expressed according to xpecific developmental patterns; 2, GH acts directly at the gastric tissue and regulates the structural and functional growth of stomach.