DNA and protein synthesis in developing rat pancreas.
To define developmental patterns, we determined the rate of protein and DNA synthesis in rat pancreas at birth, 1, 2, 3, 7, 10, 14, 21, 28 days, 2 months, 3 months, and in adults. Fragments of freshly minced pancreas were incubated with [3H]-thymidine and [14C]-leucine and the DNA and protein synthesis rates were measured. We found that DNA content was lowest at birth, rose through day 3, plateaued at about 8 mg/g wet weight through day 14, then slowly decreased to the adult value of about 5 mg/g at 2 months; protein content, although high at birth, decreased rapidly to a value of 80 mg/g at day 3 and slowly rose to the adult value of 160 mg/g; protein synthesis, low at birth, rapidly increased to about five times the adult value by day 3, and remained elevated for the 1st month; DNA synthesis was 15 times the adult rate at birth, increased to 30 times at 3 days of age, then declined slowly in an exponential fashion to the adult value. We conclude that the pancreas at birth is poised biosynthetically to undergo a rapid hyperplastic and hypertrophic response, and this process reaches a maximal rate at about 3 days of age.
D000375:Aging / Q000502:physiology*; D000818:Animals; D004247:DNA / Q000096:biosynthesis*; D008297:Male; D010179:Pancreas / Q000378:metabolism*; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains
D004247:DNA