Tissue igf-i protein and mrna responses to a single injection of
somatotropin.
Ramsay, T. G., I. B. Chung, S. M. Czerwinski, J. P. McMurtry, R. W.
Rosebrough, and N. C. Steele.
Nonruminant Nutrition Lab, USDA-ARS, Beltsville, MD 20705
APStracts 2:0094E, 1995.
Swine were divided into 4 groups of 11 animals at 40 kg bwt. Swine
within a group were given a single pST injection (200 [mu]g/kg) or
buffer at 8:00 hours. Blood, liver (L), latissimus dorsi (LD),
semitendinosus (STS), vastus lateralis (VL), dorsal subcutaneous (SQ)
and perirenal (PR) adipose tissues were sampled at 0, 1, 2, 4, 8, 12,
16 and 24 hours post injection. Blood urea nitrogen was depressed by
16 hours. Insulin was elevated by 350% at 8 hours. Lipogenic enzyme
activities in adipose tissues were not affected by pST treatment.
IGF-I mRNA levels increased rapidly in SQ, PR and L to a single pST
administration, while only slightly in VL. IGF-I mRNA concentrations
in LD and STS were unaffected by pST treatment. IGF-I protein content
of tissues changed little during the first 24 hours post-injection.
These data suggest individual tissues differ in timing and degree of
response to pST. Conflicting results reported following pST treatment
could, in part, be due to tissue selection for sampling or sample
timing.
Received 1 July 1994; accepted in final form 25 April 1995.
APS Manuscript Number E243-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 2 May 1995.