Differential regulation of mRNAs encoding for rat intestinal alkaline phosphatase.
A cDNA probe encoding the entire structural region of the 62-kDa rat intestinal alkaline phosphatase from amino acid residues 1 to 531 detected multiple mRNA species (3.0, 2.7, and 2.2 kb) in rat intestinal RNA. The 3.0-kb species was most evident in duodenum but could be easily detected in jejunum using a 48-mer oligonucleotide encoding amino acid residues 492-508. This 48-mer oligonucleotide bound preferentially to the 3.0-kb mRNA, suggesting that the 2.7-kb mRNA differed in this region. To determine whether each of the mRNAs encoding rat intestinal alkaline phosphatase responded coordinately to physiological stimuli, the full-length cDNA and the 48-mer oligonucleotide were used as probes for the 2.7- and 2.2-kb and the 3.0-kb mRNAs, respectively. Intestinal mRNA concentration was measured by Northern blot analysis in acute (single feed, 17 kcal) and chronic (3 wk, 30% fat diet) fat feeding and in rachitic rats after 1,25-dihydroxyvitamin D3 therapy. There was a large increase (8- to 25-fold) in the 3.0-kb mRNA 7 h after acute fat feeding, with a much smaller increase (1.4- to 5.0-fold) in the 2.7- and 2.2-kb species. The peak in 3.0-kb mRNA accumulation correlated in time with the maximal activity of serum phosphatase activity after acute fat feeding (4- to 5-fold increase). In contrast, there was a much smaller increase in all mRNAs and in tissue and serum enzyme activity after chronic fat feeding.(ABSTRACT TRUNCATED AT 250 WORDS)
Eliakim
R
R
Department of Medicine, Washington University, St. Louis, Missouri 63110.
Seetharam
S
S
Tietze
C C
CC
Alpers
D H
DH
D000469:Alkaline Phosphatase / Q000235:genetics*; D000818:Animals; D015152:Blotting, Northern; D002117:Calcitriol / Q000494:pharmacology*; D015342:DNA Probes; D004041:Dietary Fats / Q000494:pharmacology*; D004386:Duodenum / Q000187:drug effects; D004435:Eating; D005215:Fasting; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007413:Intestinal Mucosa / Q000201:enzymology*; D007583:Jejunum / Q000201:enzymology; D008297:Male; D015345:Oligonucleotide Probes; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D011919:Rats, Inbred Strains; D014808:Vitamin D Deficiency / Q000201:enzymology
D015342:DNA Probes; D004041:Dietary Fats; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D000469:Alkaline Phosphatase; D002117:Calcitriol