Effects of growth hormone administration on vitamin D metabolism and vitamin D receptors in the pig.
Twelve 36-kg pigs were given either 100 micrograms/kg porcine pituitary growth hormone (pGH) or placebo injections daily for 33 days. Serum was obtained weekly for analysis of minerals and vitamin D metabolites. On day 34, the pigs were sacrificed and renal and duodenal tissue were obtained for analysis of vitamin D receptor content (VDR). Animals treated with pGH grew faster and had a higher rate of bone accretion than did control animals. Serum concentrations of 1,25-dihydroxyvitamin D (1,25-(OH)2D) were significantly higher in pGH-treated pigs than in control pigs at all time points following initiation of treatment, with the greatest difference observed at day 28 (42.4 +/- 4.9 pg/ml in controls vs. 65.4 +/- 4.7 pg/ml in pGH-treated pigs). Serum 24,25-dihydroxy-vitamin D tended to be lower in pGH-treated pigs than in control pigs, being significantly lower on day 21 of the experiment (3.22 +/- .52 vs. 6.73 +/- 1.22 ng/ml, respectively). Serum concentrations of 25-hydroxyvitamin D and calcium were unaffected by pGH treatment. Kidneys of control pigs contained significantly more unoccupied vitamin D receptors than did kidneys from pGH-treated pigs (73.3 +/- 4.3 vs. 58.3 +/- 4.1 fmoles/mg protein). Duodenal tissue unoccupied vitamin D receptor content was similar in both pGH-treated (245 +/- 17.9 fmoles/mg protein) and control (263 +/- 21.8 fmoles/mg protein) pigs. Duodenal occupied vitamin D receptor concentration was similar in both pGH-treated (6.8 +/- .75 fmoles/mg protein) and control pigs (5.32 +/- .77 fmoles/mg protein).(ABSTRACT TRUNCATED AT 250 WORDS)
Goff
J P
JP
US Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Ames, IA 50010.
Caperna
T J
TJ
Steele
N C
NC
D000818:Animals; D001846:Bone Development / Q000187:drug effects; D002118:Calcium / Q000097:blood; D004386:Duodenum / Q000032:analysis; D013006:Growth Hormone / Q000494:pharmacology*; D006909:Hydroxyproline / Q000097:blood; D007668:Kidney / Q000032:analysis; D008274:Magnesium / Q000097:blood; D008297:Male; D010758:Phosphorus / Q000097:blood; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000032:analysis*; D013552:Swine / Q000254:growth & development / Q000378:metabolism*; D014807:Vitamin D / Q000378:metabolism*; D015430:Weight Gain
D018167:Receptors, Calcitriol; D011987:Receptors, Steroid; D014807:Vitamin D; D010758:Phosphorus; D013006:Growth Hormone; D008274:Magnesium; D006909:Hydroxyproline; D002118:Calcium