Effects of intravenous infusion of high levels of potassium and sodium on mineral metabolism in sheep.
A metabolism trial was conducted with 18 crossbred (Finn x Dorset x Suffolk) wethers, fitted with indwelling jugular catheters and abomasal and ileal cannulas, to determine the effects of high levels of i.v.-infused K and Na on mineral metabolism. The wethers (40 kg) were fed 800 g daily of a 60% concentrate diet in two equal portions at 0800 and 1900. Six wethers were infused randomly with 19 g K+, six with 10.6 g Na+ (chloride salts) and the other six with physiological saline solution (1.2 g Na) per day. Potassium chloride or NaCl infusion had no effects on apparent absorption, retention, flow or partial absorption of Mg, Ca and P in the digestive tract compared with physiological saline infusion. With all treatments, Mg and Ca were absorbed proximal to the abomasal cannula. Magnesium was secreted into, whereas Ca and P were absorbed from, the small intestine. Phosphorus was secreted both in the stomach and large intestinal regions of the digestive tract. Major sites of K and Na absorption were the small and large intestines, respectively. Infusion of K increased (P less than .05) retention of K compared with Na infusion. Infusion of Na increased (P less than .05) excretion and retention of Na compared with K infusion. Serum minerals were not changed by K or Na infusion compared with saline. The results of this experiment indicate that the depressing effects of K on Mg absorption are not attributable to high levels of absorbed K, but rather to K present in the digestive tract prior to the small intestine.
Rahnema
S H
SH
Dept. of Anim. Sci., Virginia Polytechnic Institute and State University, Blacksburg 24061.
Fontenot
J P
JP
D000042:Absorption; D000818:Animals; D002118:Calcium / Q000378:metabolism; D007262:Infusions, Intravenous / Q000662:veterinary; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008903:Minerals / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D011188:Potassium / Q000008:administration & dosage / Q000494:pharmacology*; D012756:Sheep / Q000378:metabolism*; D012964:Sodium / Q000008:administration & dosage / Q000494:pharmacology*
D008903:Minerals; D010758:Phosphorus; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium