ISSN:
1573-4919
Keywords:
bovine alveolar macrophages
;
insulin-like growth factors
;
insulin-like growth factor receptors
;
inositol phosphates
;
intracellular [Ca2+]
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Expression of insulin-like growth factor-I (IGF-I) receptors and insulin-like growth factor-II/mannose-6-phosphate (IGF-II/Man6P) receptors in cultured bovine alveolar macrophages (BAM) was demonstrated by competitive binding studies and crosslinking experiments. Western blotting of protein extracts from cultured BAM using an anti bovine IGF-II/Man6P receptor antiserum (#66416) confirmed the presence of IGF-II/Man6P receptors on BAM. The effects of IGFs and Man6P on generation of inositol phosphates was measured by HPLC analysis of perchloric acid extracts from myo-[3H]inositol-labelled cultured BAM. IGF-I at nanomolar concentrations and Man6P (10-8−103 M) stimulated the accumulation of both Ins(1,4,5)P3 and Ins(1,3,4,5)P4 after 30 sec. IGF-II (up to 2.3 × 10-8M) had no significant effect on inositol phosphate accumulation under the same conditions. Both IGFs and Man6P induced a rise in [Ca2+]iin cultured BAM. In addition, using the fluorescent dye SNARF-1/AM we could demonstrate rapid but small IGF-II (10-9 M) triggered acidification (0.07 pH units) of cultured BAM. Taken together, our results indicate not only the presence of both IGF-I and IGF-II/Man6P receptors on BAM, but also provide evidence of the linkage of the IGF-I receptor to the inositol phosphate system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006836631673
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