[Growth factors and mitogenic activity in experimental hypercholesterolemia].
BACKGROUND
Hypercholesterolemia is associated with increased platelet reactivity and changes in megakaryopoiesis, which might influence the synthesis of growth factors in the megakaryocyte.


METHODS
20 miniature pigs were randomly assigned to received 18 weeks of either regular pig chow feed (control group, n = 10) or a high cholesterol diet (cholesterol group, n = 10). Platelet count, mean platelet volume, platelet distribution width and bleeding time were determined in both groups. Intraplatelet and serum mitogenic activity was quantified by Swiss 3T3 and vascular smooth muscle cells proliferation assays. Insulin-like growth factor I and platelet-derived growth factor (BB isoform) levels were quantified in platelet lysates and in serum in both groups.


RESULTS
Hypercholesterolemia was associated to a significant decrease in mean platelet volume and bleeding time, but it did not affect the proliferative effect of serum and platelet lysates nor its growth factor content.


CONCLUSIONS
Taken together, our results suggest that although hypercholesterolemia affects platelet reactivity, its atherosclerosis-promoting effects cannot be explained by a direct effect on vascular smooth muscle cell proliferation or by changes in serum or intraplatelet growth factor content.
García Bolao
I
I
Departamento de Cardiología, Facultad de Medicina, Universidad de Navarra, Pamplona.
Merino
J
J
Gil
M J
MJ
Martínez
A
A
Grau
A
A
Alegría
E
E
Martínez-Caro
D
D
D016475:3T3 Cells; D000818:Animals; D001792:Blood Platelets / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D004195:Disease Models, Animal; D006937:Hypercholesterolemia / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism*; D008297:Male; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D010982:Platelet-Derived Growth Factor / Q000032:analysis / Q000378:metabolism*; D011897:Random Allocation; D013552:Swine; D013556:Swine, Miniature; D013936:Thymidine / Q000097:blood
D002791:Cholesterol, Dietary; D010982:Platelet-Derived Growth Factor; D007334:Insulin-Like Growth Factor I; D013936:Thymidine