+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

The fetal heart insulin receptor responds differently to varying plasma insulin concentrations

Developmental Pharmacology and Therapeutics 10(3): 153-162
The fetal heart insulin receptor responds differently to varying plasma insulin concentrations
We investigated in vivo the effect of varying plasma concentrations of insulin on the 28- and 30-day-old fetal rabbit heart insulin receptors using plasma membranes. Alloxan induced maternal diabetes (n = 5) associated with fetal hyperglycemia and mild hyperinsulinemia (59.80 +/- 8.10 microU/ml versus a control of 26.25 +/- 3.70, p less than 0.01) increased the insulin receptor number from a control (30 d) of 168 +/- 1.01 to 320 +/- 34 X 10(10)/mg protein (p less than 0.01). Fetal administration of 1.0 U of insulin (n = 4) resulting in normoglycemia and moderately high plasma insulin concentrations (103.3 +/- 34.63 microU/ml versus a control of 13.72 +/- 1.60, p less than 0.05) did not alter the insulin receptor number (28 d). On the other hand fetal administration of 2.0 U of insulin (n = 4) resulting in hypoglycemia and severely high plasma insulin concentrations (288.3 +/- 51 microU/ml versus a control of 13.72 +/- 1.60, p less than 0.01) decreased the insulin receptor number from a control (28 d) of 200 +/- 23 to 82 +/- 23 X 10(10)/mg protein (p less than 0.01). The receptor affinity remained constant. We conclude that the downregulation (decrease) of the fetal heart insulin receptors in vivo is not a physiologic but a pharmacologic effect of insulin.

(PDF 0-2 workdays service: $29.90)

Accession: 006677035

PMID: 3301234

Related references

Varying brain insulin concentrations differentially regulate the fetal brain insulin receptor. Biochemical & Biophysical Research Communications 136(1): 208-219, 1986

Oligomers of grape-seed procyanidin extract activate the insulin receptor and key targets of the insulin signaling pathway differently from insulin. Journal of Nutritional Biochemistry 21(6): 476-481, 2010

The effect of hyperglycemia with high low insulin concentrations on fetal and maternal brain and liver insulin receptor glycosylation. Clinical Research 36(6): 899A, 1988

Evidence that human and porcine insulin differently affect the human insulin receptor: studies with monoclonal anti-insulin receptor antibodies. Journal of Endocrinological Investigation 14(11): 913-918, 1991

Circulating insulin-like growth factor II/mannose-6-phosphate receptor and insulin-like growth factor binding proteins in fetal sheep plasma are regulated by glucose and insulin. European Journal of Endocrinology 131(4): 398-404, 1994

Fetal insulin-like growth factor (IGF)-I and IGF-II are regulated differently by glucose or insulin in the sheep fetus. Reproduction, Fertility, and Development 8(1): 167-172, 1996

High glucose and insulin decrease insulin receptor mrna and insulin receptor tyrosine kinase activity in fetal rat lung explants. Pediatric Research 31(4 PART 2): 308A, 1992

Concentrations of insulin glargine and its metabolites during long-term insulin therapy in type 2 diabetic patients and comparison of effects of insulin glargine, its metabolites, IGF-I, and human insulin on insulin and igf-I receptor signaling. Diabetes 62(7): 2539-2544, 2013

Varying concentrations of fetal hyperinsulinemia differentially affect the myocardial insulin receptors. Clinical Research 33(4): 903A, 1985

Relationships between plasma leptin and insulin concentrations, but not insulin resistance, in non-insulin-dependent (type 2) diabetes mellitus. Diabetic Medicine 14(5): 376-380, 1997