Background/aim: Platelet-rich plasma (PRP) application has gained widespread interest for musculoskeletal injuries. Nonsteroidal antiinflammatory drugs are frequently used in sports medicine before and/or after PRP application. Our study seeks to determine whether serum levels of platelet-derived growth factor-AB (PDGF-AB) and vascular endothelial growth factor (VEGF) levels of PRP would be affected by nonsteroidal antiinflammatory drugs.Materials and methods: Two different final concentrations of diclofenac (0.5 µg mL -1 and 2.5 µg mL -1 ), meloxicam (0.8 µg mL -1 and 2.0 µg mL -1 ), and acetylsalicylic acid (final concentration 450 µm) were obtained in separate tubes with PRPs prepared from 20 healthy male volunteers. Medicine-free PRP was the control group. Growth factors were measured using ELISA.Results: PDGF-AB and VEGF serum levels did not change with diclofenac, meloxicam, or acetylsalicylic acid addition. PDGF-AB and VEGF serum levels correlated with each other. Conclusion:Diclofenac, meloxicam, and acetylsalicylic acid did not affect PDGF-AB and VEGF serum levels.

To investigate the effect of sildenafil on platelet function and cyclic guanosine monophosphate (cGMP) levels in patients with erectile dysfunction, we evaluated the association between erectile function and platelet responses after administration of 100 mg sildenafil. Erectile responses were monitored after 8 daily doses of the drug. Adenosine diphosphate (ADP) and collagen-induced platelet aggregation and simultaneous adenosine triphosphate (ATP) release and cGMP levels were determined before and after sildenafil therapy. Basal levels for platelet aggregation, ATP release and cGMP were compared with age-matched controls. There was no difference among basal levels of platelet responses between patients and controls, except for ADP-induced platelet aggregation (P = 0.04). It was significantly higher in the patient group. Analysis of the responses to sildenafil revealed that for the patients who showed a positive erectile response, there was a significant increase in platelet cGMP (P = 0.028) and a decrease in ADP-induced platelet aggregation (P = 0.04). However, for those who showed a negative or poor erectile response, there was no change in platelet cGMP levels and platelet functions. Sildenafil did not affect collagen-induced platelet responses although cGMP levels of the responders increased. It is concluded that sildenafil increases platelet cGMP in the patients with positive erectile response. Therefore, it has been speculated that platelet cGMP may be used as an index for erectile response.

GPIIbIIIa, Endotel, NOSA) before and immediately after the exercise. Platelet GPIIb/IIIa significantly decreased after the exercise protocol (p=0.024). No significant difference was found between plasma NO and cGMP. There was no correlation between platelet GPIIb/IIIa and both plasma NO and platelet cGMP levels. The data was confirmed by the literature. The submaximal exercise performed in the present study was inhibited by the platelet activation since NO levels did not increase. We found no clear-cut relationship between platelet GPIIb/IIIa and plasma NO. It was thought that different mechanisms were involved in the inhibition of platelets.

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