Norepinephrine Induced Hypocalcemia in Sheep
Acta Veterinaria Scandinavica volume 11, pages 327–328 (1970)
Increased plasma levels of non-esterified fatty acids (NEFA) may lead to several physiological changes e.g. increased insulin secretion with a concomitant reduction of blood glucose, decreased glucose utilization in heart and skeletal musculature and increased blood acetone levels. High NEFA levels also cause fat infiltration in various organs especially the liver. Recently Akgün & Rudman (1969) showed that ACTH induced NEFA mobilization in rabbits was followed by hypocalcemia. Serum calcium decreased about 30 %, while the calcium content in adipose tissue increased up to 1000 %. This finding could also be verified in vitro. When adipose tissue was incubated in serum containing lipolytic hormones, lipolysis was stimulated and there was a shift of calcium from serum to tissue. A negative correlation between serum calcium and NEFA in hypocalcemic cows was reported earlier (Luthman & Jonson 1969). The purpose of the present investigation was to study the effect of increased NEFA levels on serum calcium in sheep. The animals used were ewes in late pregnancy. Lipolysis was stimulated by norepinephrine (Norexadrin, Astra). The animals were given a continuous intravenous infusion during 8 hrs. at a rate of 1 μg/kg/min. The methods of analysis were the same as described before (Luthman & Jonson).
Akgün S. & D. Rudman: Relationships between mobilization of free fatty acids from adipose tissue and the concentration of calcium in the extracellular fluid and in the tissue. Endocrinology 1969, 84, 926–930.
Barlet J. P.: Ėtude de Pinfluence du glucagon et de Parginine sur la calcemie du lapin et de la brebis. C. R. Acad. Sci. (Paris) 1969, 269, 621–624.
Luthman J. & G. Jonson: Fettmobiliseringen hos pareskor. (Lipid mobilization in cows with parturient paresis). Svensk Vet.-Tidn. 1969, 21, 686–688.
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Luthman, J. Norepinephrine Induced Hypocalcemia in Sheep. Acta Vet Scand 11, 327–328 (1970). https://doi.org/10.1186/BF03547994