GROWTH FACTORS/FUNCTION

Question 1

name this function

mitogenic for a variety of epithelial cells and fibroblasts in vitro

causes hepatic cell division in vivo

widely distributed

TGF-alpha has similar biologic activities and uses the sam e receptor

Answer 1

epidermal growth factor family (EGF)

epidermal growth factor-alpha

Question 2

stored in platelet alpha granules and produced by a variety of cells

causes migration and proliferation of fibroblasts, smooth muscle cells and monocytes

chemotactic for neutrophils

Answer 2

platelet derived growth factor (PDGF)

Question 3

bind tightly to heparin - made by a variety of cells

2 forms

• acidic
• basic

angiogenesis

wound repair

skeletal muscle and lung formation

hematopoiesis

Answer 3

fibroblast growth factor (FGF)

Question 4

belongs to a family of homologous polypeptides

produced in an inactive form

conflicting roles

indirectly:
low concentration promotes growth

high concentration inhibits growth

directly:
increases collagen concentration

stimulates fibroblast chemotaxis and production of collagen and fibronectin and inhibits collagen degradation

Answer 4

transforming growth factor-B (TGF-B)

Question 5

family of related growth factors that takes part in angiogenesis

Answer 5

vascular endothelial growth factor (VEGF)

Question 6

induce fibroblast proliferation

chemotactic for fibroblasts

stimulates synthesis of collagen and collagenases

Answer 6

cytokines (IL-1 and TNF)