Observation on the use of 1 alpha-hydroxyvitamin D3 in the prevention of bovine parturient paresis: the effect of a single injection on plasma 1 alpha-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, calcium, and hydroxyproline.
Israeli Friesian cows in the third or later lactation, were injected intramuscularly with 1 alpha-hydroxyvitamin D3 in propylene glycol. Plasma 1 alpha-hydroxyvitamin D3 peaked 24 to 48 h after 700 micrograms of the drug was injected and decreased to the initial concentration 4 d later. The disappearance rate of 1 alpha-hydroxyvitamin D3 from the blood was .330 d-1 (biological half-life of 2.1 d). Plasma 1,25-dihydroxyvitamin D3 peaked 24 to 48 h after the injection and approached the initial concentration 5 to 7 d later. Plasma calcium increased within 24 h, reached a plateau at 4 to 6 d, and then decreased. Administration of 700 micrograms 1 alpha-hydroxyvitamin D3 resulted in higher plasma 1,25-dihydroxyvitamin D3 and calcium concentrations than when 350 micrograms of the drug was injected. 1 alpha-Hydroxyvitamin D3 did not affect plasma hydroxyproline. The injection of 700 micrograms 1 alpha-hydroxyvitamin D3 52 to 36 h before parturition resulted in a greater increase in plasma 1,25-dihydroxyvitamin D3 than that obtained with 350 micrograms. In both groups 1,25-dihydroxyvitamin D3 peaked 24 h after injection, as opposed to the controls, which peaked 72 h postpartum. At parturition, the 700-micrograms dose resulted in a slight hypercalcemia; the 350-micrograms dose moderated the hypocalcemia prevalent during this period, whereas in controls hypocalcemia was more pronounced. In cows injected with 700 micrograms, hypercalcemia was observed until the 15th d postpartum. Plasma hydroxyproline was elevated in all cows 48 to 72 h after parturition, but the increase was smaller in animals injected with 1 alpha-hydroxyvitamin D3.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002117:Calcitriol / Q000097:blood*; D002118:Calcium / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000517:prevention & control*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006887:Hydroxycholecalciferols / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006909:Hydroxyproline / Q000097:blood*; D007273:Injections, Intramuscular / Q000662:veterinary; D010319:Parturient Paresis / Q000097:blood / Q000517:prevention & control*; D011247:Pregnancy
D006887:Hydroxycholecalciferols; D002117:Calcitriol; D006909:Hydroxyproline; D002118:Calcium; C008088:alfacalcidol