Growth hormone (GH) and muscle quality
GH production drops by 60% at age 60. A senior who had been taking asthma meds for a long time experienced severe neck and shoulder bone fracture from a fall. Know that some meds can impair muscle quality.
The following factors influence GH secretion spike by the pituitary gland in the brain:
|Factors Increasing GH Secretion||Factors Decreasing GH Secretion|
|Fasting||Elevated Blood Free Fatty Acids|
|High Amino Acids
in the Blood
|Hyper or Hypothyroidism|
|Low Blood Sugar|
|Any hypoglycemic agent||GH itself|
|Alpha-agonists||Alpha antagonists (yohimbine)|
|Beta antagonists||Beta agonists (ephedrine, clenbuterol)|
Source: Basic and Clinical Endocrinology, 5th Edition
Muscle growth and capacity to regenerate upon injury are faster for skeletal muscle but poor for cardiac muscle especially for young ones.
A greater capacity for regeneration of cardiac muscle is seen in fish. Fish oil, folate, Vitamin Bs, Coenzyme Q10 and omega 3 dietary supplements are important for our heart muscles.
Skeletal muscle has an excellent capacity for regeneration. Inflammation and innervation makes regeneration suboptimal for seniors.
As we age, our cardiac muscles are easily affected even from those who have regular exercise and eat healthy.
Muscle regeneration is the process by which damaged skeletal, smooth or cardiac muscle undergoes biological repair and formation of new muscle in response to death of muscle cells.
- Necrosis is required for muscle regeneration.
- Inflammation is essential to remove necrotic tissue and initiate myogenesis.
- New blood vessel formation is required after major injury of muscles.
- Reinnervation is essential for functional recovery of skeletal muscle.
Adult skeletal muscle is a postmitotic tissue, accomplished by resident stem cells, satellite glial cells (SGCs). Current theories suggest that SGCs are important in controlling the microenvironment of the sympathetic ganglia.
SGCs role as a regulator of neuronal microenvironment is further characterized by its electrical properties which are very similar to those of astrocytes. Astrocytes have a well-studied and defined role in controlling the microenvironment within the brain.