Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20645 (mannose-6-phosphate receptor)
 320 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is a developmental difference in the initial phase of compensatory renal growth (CRG) following unilateral nephrectomy (UNX), in that CRG is GH-dependent in adult rats and GH-independent in immature rats. Furthermore, CRG in immature rats is associated with an increase in renal IGF-I mRNA, an effect not seen in adult rats. In this study we have examined the age-related differences in expression of the insulin-like growth factor-I (IGF-I) and IGF-II genes as well as in IGF-I and IGF-II receptors and membrane binding after UNX. Immature (22-24 days of age) and adult (4 months of age) male Wistar rats underwent a sham operation or left UNX and were killed 24 or 48 h later. Levels of mRNA for IGF-I and IGF-II and their receptors were determined in the left (control) and right (compensated) remnant kidneys using solution hybridization/RNase protection assays. Steady state levels of IGF-I mRNA as well as IGF-I receptor and IGF-II/mannose-6-phosphate receptor mRNAs were increased 3- to 4-fold in immature remnant kidneys, but not in adult kidneys. The findings related to IGF-I gene expression were confirmed by in situ hybridization to immature and adult kidney slices. The increase in IGF-I gene expression in the immature remnant kidneys was localized to the thick ascending limbs of the loops of Henle. Furthermore, in concert with the changes in mRNA levels, membrane binding studies showed significant increases in specific binding to IGF-I in cortical membranes and increases in specific binding to IGF-II in whole kidney membranes from immature, but not adult, rats. Thus, these findings demonstrate that the initial phase of CRG in the immature rat is associated with increased renal IGF-I gene expression as well as enhanced specific renal binding of IGF-I and IGF-II to plasma membranes and support the notion that this period of rapid renal growth in the immature UNX rat may involve the paracrine influence of the IGFs.
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PMID:Altered expression of insulin-like growth factor-I (IGF-I) and IGF receptor genes after unilateral nephrectomy in immature rats. 130 31

Solution hybridization/RNase protection assays were used to study the developmental expression of the insulin-like growth factor-I (IGF-I), IGF-II, IGF-I receptor, and IGF-II/mannose-6-phosphate receptor genes in the rat ovary between postnatal days 1-80. Maximal IGF-I mRNA levels occurred during the 15- to 25-day postnatal period, and the level on day 20 represented a 9-fold increase over the baseline at earlier and later stages. IGF-II mRNA levels were maximal during the 1- to 5-day postnatal period and subsequently declined to undetectable levels after day 10. IGF-I receptor mRNA levels increased 10-fold to a maximum in the 20- to 25-day postnatal period. This pattern was similar to the developmental pattern of [125I]IGF-I binding in the ovary. Two apparent peaks of IGF-II/mannose-6-phosphate receptor mRNA levels were seen, on day 20 and between days 50-80. These specific and significant changes in the expression of the genes encoding the IGFs and their receptors suggest a role for the IGF system in postnatal ovarian development.
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PMID:Expression of the insulin-like growth factor (IGF)-I and -II and the IGF-I and -II receptor genes during postnatal development of the rat ovary. 132 54

The intraovarian insulin-like growth factor (IGF) system constitutes a triad composed of ligands, receptors, and binding proteins. Although conventional radioligand receptor assays have documented the presence of specific receptors for insulin and insulin-like peptides in some rat somatic ovarian cell types, the exact cellular localization and hormonal regulation of the receptors in question remain matters of inquiry. To reevaluate the very presence, cellular localization, and hormonal regulation of the IGF receptor gene family in the rat ovary, solution hybridization/RNase protection assays were used wherein ovarian total RNA (20 micrograms) from immature (21-23 days old) rats was hybridized with 32P-labeled type I IGF receptor, type II IGF/mannose-6-phosphate receptor, and insulin receptor riboprobes. Single protected fragments 261 (type I IGF receptor), 500 (type II IGF/mannose-6-phosphate receptor), and 478 (insulin receptor) bases long were evident in whole ovary, granulosa, and theca-interstitial cells. Hypophysectomy of immature rats led to significant (P less than 0.05) albeit variable decrements in the relative (densitometrically quantified) ovarian abundance of transcripts corresponding to the type I IGF (but not insulin or type II IGF/mannose-6-phosphate) receptor. Treatment of immature hypophysectomized rats with FSH (10 micrograms/rat.day x 2.5 days) resulted in a significant (P less than 0.05) increase (4-fold) in transcripts corresponding to the type I IGF receptor in both whole ovarian material and freshly isolated granulosa cells. Similar (3.7-fold) increments (P less than 0.05) were noted after treatment with a diethylstilbestrol-containing sc silastic implant applied for a total of 5 days.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Insulin-like growth factor receptor gene expression in the rat ovary: divergent regulation of distinct receptor species. 172 86