Insulin receptor number and binding affinity in newborn dogs

Area of Science:

• Endocrinology
• Metabolic Research
• Mammalian Physiology

Background:

• Neonatal insulin resistance is a clinical concern.
• Insulin resistance may involve receptor or postreceptor defects.
• Limited data exists on insulin receptors in neonatal non-hepatic tissues.

Purpose of the Study:

• To investigate insulin receptor characteristics in neonatal canine skeletal muscle, heart, and liver.
• To compare insulin receptor number and affinity between neonatal and adult canines.
• To elucidate the role of insulin receptors in neonatal insulin resistance.

Main Methods:

• Wheat germ lectin affinity chromatography for receptor purification.
• Competition binding studies to assess insulin receptor binding.
• Scatchard plot analysis to estimate receptor number and affinity.

Main Results:

• Increased specific insulin binding in newborn skeletal muscle and heart compared to adults.
• Higher high-affinity insulin receptor numbers in newborn skeletal muscle and heart.
• No significant differences in insulin receptor affinity or liver tissue characteristics between newborns and adults.

Conclusions:

• Neonatal skeletal muscle and heart exhibit altered insulin receptor numbers.
• These alterations may contribute to neonatal insulin resistance.
• Liver insulin receptor characteristics remain similar between neonatal and adult canines.