Nitrite μM Nitrate μM Control 7.85 ± 1.44 8.55 ± 1.32 ACh 10 μM 12.35 ± 1.87 11.25 ± 1.32 Timolol 10 μM 10.95 ± 0.58 12.90 ± 2.14

Table 2: Mean ± sd values of nitrite and nitrate concentration obtained in untreated (Control) and treated blood samples with acetylcholine (ACh) 10 μM and timolol 10 μM.