Changes in plasma renin activity after hypoglycaemia in sympathectomized man

Area of Science:

• Endocrinology
• Neuroscience
• Physiology

Background:

• Acute insulin-induced hypoglycemia affects glucose regulation.
• The sympathoadrenal system plays a role in hormonal responses to stress.
• Renin release is a key component of the renin-angiotensin-aldosterone system.

Purpose of the Study:

• To investigate the role of the sympathoadrenal system in mediating renin release during hypoglycemia.
• To compare the responses of normal and tetraplegic subjects to insulin-induced hypoglycemia.

Main Methods:

• Measurements of blood glucose, plasma noradrenaline, and plasma renin activity.
• Induction of acute hypoglycemia using insulin (0.15 unit/kg).
• Comparison between 11 normal subjects and 6 tetraplegic subjects with cervical spinal cord transection.

Main Results:

• Hypoglycemia caused a significant rise in plasma noradrenaline in normal subjects.
• The increase in plasma noradrenaline was absent in tetraplegic subjects.
• Plasma renin activity markedly increased in both normal and tetraplegic groups.

Conclusions:

• Renin release in response to hypoglycemia can occur independently of sympathoadrenal system activation.
• The findings suggest a non-sympathetic pathway for renin stimulation during hypoglycemia.