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.
Collagen occurs throughout the body, but especially in the skin, bones, and connective tissues. Some types of collagen fibrils, gram-for-gram, are stronger than steel. Collagen production declines with age and exposure to factors such as smoking and UV light. Collagen can be used in collagen dressings, to attract new skin cells to wound sites. Cosmetic lotions that claim to increase collagen levels are unlikely to do so, as collagen molecules are too large to be absorbed through the skin.