Investigation of the effects of enteral hormones on the pyloric muscle in newborn rats.
OBJECTIVE
To investigate the effects of enteral hormones on pyloric muscle in order to clarify the etiopathogenesis of hypertrophic pyloric stenosis (HPS).


METHODS
Forty-two newborn Wistar-Albino rats were included. No intervention was done in the control group (CG, n=6). In the sham group (SG, n=6) 1ml saline (0.9% NaCl solution), in the Nw-nitro-l-arginine methyl ester hydrochloride (L-NAME) group (LNG, n=6) 100mg/kg/d L-NAME, in the somatostatin group (STG, n=6) 7mcg/kg/d ST, in the cholecystokinin group (CCKG, n=6) 3mcg/kg/d CCK, in the substance P group (SPG, n=6) 5ml/kg/d SP, and in the prostaglandin-E1 group (PGE1G, n=6) a cumulative dose of 360mcg/kg PGE1 was given intraperitoneally for 14days. On the 21st day, histopathological examination and muscle thickness measurements were done. Results were evaluated statistically.


RESULTS
Total and circular pyloric muscle thicknesses were significantly increased in the LNG compared to the CG and SG (p<0.05). Circular pyloric muscle thickness was not increased in the STG, CCKG and SPG compared to the CG and SG (p>0.05). In the PGE1G, muscle thickness was significantly decreased in the pylorus and increased in the antrum compared to the CG and SG (p<0.05).


CONCLUSIONS
Nitric oxide synthase (NOS) inhibition with L-NAME seems to be a causative factor in HPS by increasing pyloric muscle thickness. PGE predominantly affects antral gastric muscle and has no profound effect on pyloric muscle.
Kırıkkale University, Medical Faculty, Department of Pediatric Surgery, Kırıkkale, Turkey. Electronic address: ozlemboy80@yahoo.com.
Ozlem
O
Boybeyi
Hacettepe University, Medical Faculty, Department of Pediatric Surgery, Ankara, Turkey.
Tutku
T
Soyer
Kırıkkale University, Medical Faculty, Department of Pathology, Kırıkkale, Turkey.
Pınar
P
Atasoy
Kırıkkale University, Medical Faculty, Department of Pediatric Surgery, Kırıkkale, Turkey.
Yasemin Dere
YD
Gunal
Kırıkkale University, Medical Faculty, Department of Pediatric Surgery, Kırıkkale, Turkey.
Mustafa Kemal
MK
Aslan
D000818:Animals; D000831:Animals, Newborn; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D046248:Pyloric Stenosis, Hypertrophic / Q000209:etiology* / Q000473:pathology; D011708:Pylorus / Q000187:drug effects* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; C026512:arginine methyl ester; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester
Enteral hormones; Hypertrophic pyloric stenosis; L-NAME; Prostaglandin; Pyloric muscle