EFFECT OF PENICILLAMINE ON NEW AND PRE-EXISTING [3H]COLLAGEN IN-VIVO

1. 1. Prelabeled rats in an isotopic steady state were used to study the effect of penicillamine in vivo. This approach was used to distinguish the effect of penicillamine on newly synthesized salt-soluble collagen from that on preformed insoluble collagen or acid-soluble collagen. 2. 2. The administration of d-penicillamine to mature rats, 6 or 12 weeks after multiple labeling with [3H]proline, resulted in a large increase in the amount of neutral salt-soluble collagen of skin. No effect was seen on the amount of acid-soluble collagen or urinary hydroxyproline. 3. 3. Penicillamine had no effect on the specific activity (relative to insoluble collagen) of neutral salt-soluble or acid-soluble collagen, and urinary hydroxyproline. The increase in total radioactivity observed in neutral salt-soluble collagen was due to the increase in pool size. 4. 4. The absence of change in the total amount or specific radioactivity of urinary hydroxyproline is consistent with penicillamine blocking the maturation of salt-soluble collagen to insoluble collagen without affecting the rate of collagen synthesis or destruction, and without converting pre-existing collagen to the salt-soluble state. 5. 5. Under these conditions the increase in pool size of salt-soluble collagen did not affect the amount of urinary hydroxyproline. © 1969.