PMID- 17204455
OWN - NLM
STAT- MEDLINE
DCOM- 20070403
LR  - 20181201
IS  - 0006-3002 (Print)
IS  - 0006-3002 (Linking)
VI  - 1771
IP  - 2
DP  - 2007 Feb
TI  - Effects of bile diversion in rats on intestinal sphingomyelinases and ceramidase.
PG  - 196-201
AB  - Alkaline sphingomyelinase (Alk-SMase) and neutral ceramidase (N-CDase) in the 
      intestinal microvillar membrane are responsible for dietary sphingomyelin 
      digestion. The activities of the enzymes require the presence of bile salt, and 
      the enzymes can be released into the gut lumen in active forms by bile salts and 
      trypsin. It is unclear to what extent that the intestinal presence of bile salts 
      is critical for the intraluminal activity of these enzymes. We compared the 
      activities of Alk-SMase, N-CDase, and other types of SMases in control and 
      permanently bile diverted rats. In the intestinal tract of control rats, the 
      activity of Alk-SMase was profoundly higher than those of acid and neutral 
      SMases. Bile diversion reduced Alk-SMase activity by 85% in the small intestinal 
      content, and by 68% in the faeces, but did not significantly change the activity 
      in the intestinal mucosa. Western blot showed a marked reduction of the enzyme in 
      the intestinal lumen but not mucosa. N-CDase activities both in the intestinal 
      mucosa and content were reduced by bile diversion. Bile diversion also decreased 
      aminopeptidase N activity in the content and increased that in the mucosa, but 
      had no effects on that of alkaline phosphatase. In conclusion, the presence of 
      bile salts is important for maintaining high intraluminal levels of Alk-SMase and 
      N-CDase, two key enzymes for hydrolysis of sphingomyelin in the gut. We speculate 
      that the sphingomyelin hydrolysis in cholestatic conditions is impaired not only 
      by reduced hydrolytic activity but also by deficient dissociation of the enzymes 
      from the membrane.
FAU - Duan, R D
AU  - Duan RD
AD  - Gastroenterology Lab., Biomedical Center, B11, Lund University, S-221 84 Lund, 
      Sweden. rui-dong.duan@med.lu.se
FAU - Verkade, H J
AU  - Verkade HJ
FAU - Cheng, Y
AU  - Cheng Y
FAU - Havinga, R
AU  - Havinga R
FAU - Nilsson, A
AU  - Nilsson A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20061215
PL  - Netherlands
TA  - Biochim Biophys Acta
JT  - Biochimica et biophysica acta
JID - 0217513
RN  - EC 3.1.4.12 (Sphingomyelin Phosphodiesterase)
RN  - EC 3.5.- (Amidohydrolases)
RN  - EC 3.5.1.23 (Asah2 protein, rat)
RN  - EC 3.5.1.23 (Ceramidases)
RN  - EC 3.5.1.23 (Neutral Ceramidase)
SB  - IM
MH  - Amidohydrolases/*metabolism
MH  - Animals
MH  - Bile/*physiology
MH  - Ceramidases
MH  - Colon/enzymology
MH  - Feces/enzymology
MH  - Intestinal Mucosa/*metabolism
MH  - Intestine, Small/enzymology
MH  - Intestines/*enzymology
MH  - Male
MH  - Neutral Ceramidase
MH  - Rats
MH  - Rats, Wistar
MH  - Sphingomyelin Phosphodiesterase/*metabolism
EDAT- 2007/01/06 09:00
MHDA- 2007/04/04 09:00
CRDT- 2007/01/06 09:00
PHST- 2006/09/12 00:00 [received]
PHST- 2006/11/14 00:00 [revised]
PHST- 2006/12/04 00:00 [accepted]
PHST- 2007/01/06 09:00 [pubmed]
PHST- 2007/04/04 09:00 [medline]
PHST- 2007/01/06 09:00 [entrez]
AID - S1388-1981(06)00345-3 [pii]
AID - 10.1016/j.bbalip.2006.12.001 [doi]
PST - ppublish
SO  - Biochim Biophys Acta. 2007 Feb;1771(2):196-201. doi: 
      10.1016/j.bbalip.2006.12.001. Epub 2006 Dec 15.