Inhibition of Adenylate Cyclase: The muscarinic receptor, through interaction with an inhibitory GTP-binding protein, acts to inhibit adenylyl cyclase. Reduced cAMP production leads to reduced activation of cAMP-dependent protein kinase, reduced heart rate, and contraction strength.
In someone suffering with scleroderma, collagen (a protein manufactured by the connective tissues of the body) is produced in excess. This over-production of collagen can be likened to the process of scarring, which is the way the body heals a wound. For persons with scleroderma, the scarring gets out of hand.
The disorder results from overproduction of collagen, a naturally occurring protein found in the skin. It is unknown what causes this overproduction of collagen to occur but the immune system is believed to play a significant role. Morphea is not contagious or passed down in families.