Model of homeostatic regulation of potassium excretion in sheep.

Based on experimental observations on unanesthetized sheep, a hypothesis is proposed for the homeostatic control of potassium excretion in this ruminant. This hypothesis includes as a novel element a splanchnic sensor of potassium intake. Information provided by the splanchnic sensor contributes to the control of potassium excretion independently of the level of systemic plasma potassium or other conventional control factors. A mathematical model based on this hypothesis successfully simulates the relations between potassium excretion, plasma potassium, and oral and intravenous potassium input observed in sheep.