Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.30.1 (
S1 nuclease
)
3,660
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Insulin-like growth factor I
(
IGF-I
) has been shown to participate in feedback inhibition of growth hormone (GH) secretion at the level of both the pituitary and hypothalamus. Therefore, we tested the possible involvement of
IGF-I
on somatostatin (SRIF) and GH-releasing factor (GRF) release in median eminence (ME) fragments and periventricular nucleus (PeN) of male rats. The levels of SRIF messenger ribonucleic acid (mRNA) were also determined in PeN incubated in vitro with
IGF-I
. The ME's were incubated in Krebs-Ringer bicarbonate glucose buffer in the presence of various concentrations of
IGF-I
(10(-7) to 10(-11) M) for 30 min. SRIF and GRF released into the medium were quantitated by RIA. The release of SRIF and GRF from the ME's was stimulated significantly (P < 0.025 and P < 0.05, respectively) by 10(-9) M
IGF-I
. To determine whether the effect of
IGF-I
on SRIF release is mediated by GRF release in the ME, a specific GRF antibody (ab) (1:500) was used concomitantly with
IGF-I
(10(-9) M). The release of SRIF induced by
IGF-I
was blocked by the GRF ab (P < 0.001), but not by normal rabbit serum used at the same dilution. To determine the effect of
IGF-I
on the regulation of SRIF mRNA levels, SRIF mRNA was determined in PeN explants incubated in the presence of
IGF-I
(10(-8) to 10(-10) M) for 2 to 6 h. Levels of SRIF mRNA were determined by a
S1 nuclease
protection assay using a 32P-labelled rat SRIF riboprobe.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Insulin-like growth factor I modulates hypothalamic somatostatin through a growth hormone releasing factor increased somatostatin release and messenger ribonucleic acid levels. 790 98
