Sphincter contractility after muscle-derived stem cells autograft into the cryoinjured anal sphincters of rats.
OBJECTIVE
This study was designed to determine whether the injection of muscle-derived stem cells into the anal sphincter can improve functional properties in a fecal incontinence rat model.


METHODS
Cryoinjured rats were utilized as a fecal incontinence model. The gastrocnemius muscles of normal three-week-old female Sprague-Dawley rats were used for the purification of the muscle-derived stem cells. The experimental group was divided into three subgroups: normal control; cryoinjured; and muscle-derived stem cells (3 x 10(6) cells) injection group of cryoinjured rats. All groups were subsequently employed in contractility experiments using muscle strips from the anal sphincter, one week after preparation.


RESULTS
Contractility in the cryoinjured group was significantly lower than in the control after treatment with acetylcholine and KCl. In the muscle-derived stem cells injection group, contraction amplitude was higher than in the cryoinjured group but not significantly (20.5 +/- 21.3 vs. 17.3 +/- 3.4 g per gram tissue, with acetylcholine (10(-4) mol/l); 31 +/- 14.2 vs. 18.4 +/- 7.9 g per gram tissue, with KCl (10(-4) mol/l)). PKH-26-labeled transplanted cells were detected in all of the grafted sphincters. Differentiated muscle masses stained positively for alpha smooth muscle actin and myosin heavy chain at the muscle-derived stem cells injection sites.


CONCLUSIONS
This is the first study reporting that autologous muscle-derived stem cell grafts may be a tool for improving anal sphincter function.
Kang
Sung-Bum
SB
Department of Surgery, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, Korea.
Lee
Haet Nim
HN
Lee
Ji Young
JY
Park
Jun-Seok
JS
Lee
Hye Seung
HS
Lee
Ji Youl
JY
D000109:Acetylcholine / Q000494:pharmacology; D001003:Anal Canal / Q000293:injuries* / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D002478:Cells, Cultured; D018678:Cholinergic Agents / Q000494:pharmacology; D003080:Cold Temperature / Q000009:adverse effects; D005242:Fecal Incontinence / Q000209:etiology / Q000628:therapy*; D005260:Female; D023421:Models, Animal; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D033581:Stem Cell Transplantation; D014182:Transplantation, Autologous
D018678:Cholinergic Agents; D000109:Acetylcholine