Impaired esophageal reactivity in adriamycin-induced rat esophageal atresia: an in vitro study.
OBJECTIVE
The aim of this study was to investigate the reactivity of lower esophageal smooth muscle in the Adriamycin-induced esophageal atresia (EA) rat model.


METHODS
The fetuses were divided into 3 groups. The control group was exposed to saline. The second group comprised fetuses that were exposed to Adriamycin but in whom EA did not develop. The third group comprised of fetuses that were exposed to Adriamycin and EA was observed. The reactivity of distal esophageal strips was studied in organ chambers.


RESULTS
The tension was similar in all groups precontracted with carbachol for the study of relaxation to serotonin. Relaxation of lower esophageal strips to serotonin was comparably unaffected in the control and Adriamycin-no EA groups, whereas it was significantly inhibited in the EA group with decreased E(max) and pD(2) values. Contractile responses of esophageal smooth muscle to carbachol or 80 mmol/L KCl and relaxant responses to papaverine were similar in all groups. No change in agonist potency was observed among the groups.


CONCLUSIONS
Our study showed impairment of serotonin-receptor-mediated relaxation; but not of cholinoceptor-mediated contraction of the lower esophageal smooth muscle in the EA. Thus, impaired relaxant responses may be, at least in part, a contributing factor in the esophageal dismotility seen in EA.
Tugay
M
M
Department of Pediatric Surgery and Pharmacology, Kocaeli University, School of Medicine, Kocaeli, Turkey.
Yildiz
F
F
Utkan
T
T
Ulak
G
G
Gacar
N
N
Erden
F
F
D000818:Animals; D004195:Disease Models, Animal; D004317:Doxorubicin / Q000009:adverse effects; D004933:Esophageal Atresia / Q000139:chemically induced / Q000503:physiopathology*; D005260:Female; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000502:physiology*; D011985:Receptors, Serotonin / Q000502:physiology*
D011976:Receptors, Muscarinic; D011985:Receptors, Serotonin; D004317:Doxorubicin