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.
Scleroderma, a rare autoimmune disease characterized by abnormal connective tissue growth, can wreak havoc on everything from the skin and heart to lungs, teeth, speech, and movement. The overproduction of collagen causes the skin and organs to harden, leading them to atrophy and possibly fail.
Estrogen therapy has a beneficial effect upon collagen, thus improving the texture of the skin, the nails, the intervertebral discs and bone matrix. Discussion of side-effects should not be avoided, particularly the 1% extra lifetime risk of breast cancer.