title: Seasonal changes in sodium transport and amiloride sensitivity in the isolated intestine of the earthworm, Lumbricus terrestris (L.).
abstract: Temporal changes in sodium flux rates and the electrical properties of two regions of the intestine appear to occur in a yearly cycle. In RIIIA, the anterior portion of the mid-intestine, the short-circuit current in January and April preparations is 60.2 and 10.2 microA cm-2, respectively and the net sodium fluxes are 1.50 and 1.24 mu Eq cm-2 hr-1, respectively. In RIIIB, the posterior portion of the mid-intestine, the short-circuit current in January and April preparations is 50.7 and 27.9 microA cm-2, respectively, while the net sodium fluxes are 1.78 and 0.59 mu Eq cm-2 hr-1, respectively. Sodium transport in RIIIB is inhibited by amiloride (10(-4)M) in January preparations but is refractory to amiloride (less than or equal to 10(-3)M) in April preparations.
mesh_terms: D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D004351:Drug Resistance; D004553:Electric Conductivity; D004594:Electrophysiology; D007408:Intestinal Absorption / Q000187:drug effects*; D007422:Intestines / Q000502:physiology*; D009835:Oligochaeta / Q000502:physiology*; D011719:Pyrazines / Q000494:pharmacology*; D012621:Seasons; D012964:Sodium / Q000378:metabolism*
chemical_list: D011719:Pyrazines; D000584:Amiloride; D012964:Sodium