Colchicine blocks the effects of secretin on bile duct cell tubulovesicles and plasma membrane geometry and impairs ductular HCO3- secretion in the pig.
Secretin causes the bile duct cells to secrete HCO3-. To examine whether the transformation of duct cell ultrastructure that follows secretin stimulation depends on microtubules and is important for ductular HCO3- secretion, we examined the effect of colchicine on ductular HCO3- secretion and on the morphology of cells lining bile ductules of anaesthetized pigs. Colchicine blocked secretin-dependent cytoplasmic clearance of tubulovesicles and prevented expansion of the basolateral plasma membrane in duct cells and reduced the ductular HCO3- secretory response from 132 +/- 25 mumol min-1 to 97 +/- 14 mumol min-1. In contrast, lumicolchicine did not affect secretin-dependent tubulovesicle clearance or plasma membrane geometry or ductular HCO3- secretion. Accordingly, secretin-dependent cytoplasmic clearance of tubulovesicles in bile duct cells appears to depend on microtubules and to be important for ductular HCO3- secretion.
Veel
T
T
Institute for Experimental Medical Research, Ullevaal Hospital, Oslo, Norway.
Buanes
T
T
Grotmol
T
T
Engeland
E
E
Raeder
M G
MG
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001652:Bile Ducts / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D003078:Colchicine / Q000494:pharmacology*; D008162:Lumicolchicines / Q000494:pharmacology; D008870:Microtubules / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D012633:Secretin / Q000502:physiology*; D013552:Swine
D001639:Bicarbonates; D008162:Lumicolchicines; D012633:Secretin; C042109:lumicolchicine; D003078:Colchicine