[Changes induced by ouabain and colchicine in the transdentinal flow estimated in vivo by perfusion: the "push-pull" of the incisors of rats].
The active or passive mechanisms regulating the various movements of dentinal fluid have not yet been sufficiently studied. For this reason different "in vivo" factors that may modulate the kinetics of transdentinal flow were investigated. After systemic administration of a radiotracer in rats, the kinetics were examined with a push-pull perfusion device fixed to the incisor dentin. The drugs chosen, i.e. ouabain and colchicine, were for their respective effects on microtubules and on the ATPase-dependent Na+ K+ pump, since these two factors are involved in the transport process. Anesthetized animals were prepared to allow intravenous injection of iodine 125 (0,5 to 0,7 mCi), carotid sampling, and perfusion of upper incisors. Ouabain induced a very significant decrease in transdentinal flow, which was particularly evident in younger animals (2,81 x 10(-2) % vs 0,04 x 10(-2)%, p less than 0,05). However, colchicine produced two different kinds of results : at low doses (3,5 to 5 mg/100 g) the pulsatile pattern of the curves was partially inhibited, whereas, at higher doses (6 to 7 mg/100 g), the transdentinal flow of radioactivity increased. These results suggest that a combination of active and passive transport may be involved in the various movements of this fluid.
Litovsky
B
B
Laboratoire de Physiologie, Université de Montpellier.
Arancibia
S
S
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D003078:Colchicine / Q000494:pharmacology*; D003804:Dentin / Q000378:metabolism*; D003806:Dentin Permeability / Q000187:drug effects*; D007457:Iodine Radioisotopes; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology*; D010477:Perfusion / Q000379:methods; D051381:Rats; D011919:Rats, Inbred Strains; D014088:Tooth Permeability / Q000187:drug effects*
D007457:Iodine Radioisotopes; D007473:Ion Channels; D010042:Ouabain; D003078:Colchicine
Modification par ouabaïne et colchicine du flux transdentinaire estimé in vivo par perfusion: "push-pull" d'incisives de rats.