Influence of exogenous porcine growth hormone on vitamin D metabolism and calcium and phosphorus absorption in intact pigs.
The influence of growth hormone (GH) on vitamin D metabolism and calcium and phosphorus absorption in vivo is not clear. We, therefore, measured calcium and phosphorus balance, plasma 1,25-dihydroxyvitamin D (1,25(OH)2D), and intestinal vitamin D-dependent calcium-binding protein (CaBP 9k) in intact growing pigs given exogenous GH. Six 10-week-old pigs were given two daily subcutaneous injections of 50 micrograms porcine GH/kg body weight for 2 months; six control pigs were given vehicle. They were all fed a diet containing 1.1% Ca, 0.6% P, and 1000 IU vitamin D3/kg. Apparent Ca and P absorption and retention were measured in a 10-day balance trial at the end of the 2 months. The plasma levels of Ca, P, 1,25(OH)2D, IGF-I, and GH were determined, and the duodenal and jejunal mucosal CaBP 9k content was measured at slaughter. The plasma Ca and P of GH-treated pigs were unchanged, but all aspects of mineral metabolism, including the plasma 1,25(OH)2D concentration (40%), Ca absorption and retention (70%), P absorption (33%) and retention (45%), and jejunal CaBP 9k (40%), were stimulated, in addition to an increase in the circulating IGF-I concentration.
Denis
I
I
Laboratorie de Nutrition et Sécurité Alimentaire, INRA, Jouy-en-Josas, France.
Thomasset
M
M
Pointillart
A
A
D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001835:Body Weight; D002117:Calcitriol / Q000032:analysis / Q000097:blood; D002118:Calcium / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000097:blood; D004386:Duodenum / Q000737:chemistry; D013006:Growth Hormone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007279:Injections, Subcutaneous; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000737:chemistry; D007583:Jejunum / Q000737:chemistry; D008297:Male; D010758:Phosphorus / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D013552:Swine / Q000378:metabolism*; D014807:Vitamin D / Q000378:metabolism* / Q000502:physiology
D002135:Calcium-Binding Proteins; D014807:Vitamin D; D010758:Phosphorus; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D000469:Alkaline Phosphatase; D002117:Calcitriol; D002118:Calcium