Ts100 f microscope

Artery segments (1–2 mm length) were cannulated in a perfusion chamber (Living Systems Instrumentation, St. Albans, VT) and continuously perfused with 37 °C physiological saline solution (PSS) which contained: 112 NaCl, 4.8 KCl, 24 NaHCO₃, 1.8 CaCl₂, 1.2 MgSO₄, 1.2 KH₂PQ₄ and 10 glucose, gassed with mixture of 21% O₂, 5% CO₂ and 74% N₂. The endothelium was denuded by introducing an air bubble into the lumen for ~1 minute followed by wash with PSS. Arterial diameter was measured at an intravascular pressure of 60 mmHg, which was monitored using a pressure transducer. Arterial diameter was measured using a CCD camera attached to a Nikon TS100-F microscope and the edge-detection function of IonWizard (Ionoptix, Milton, MA). Myogenic tone (%) was calculated as: 100 × (1 – D_active/D_passive), where D_active is active arterial diameter and D_passive is the diameter determined in Ca²⁺-free PSS supplemented with 5 mmol/L EGTA.

Artery segments (1–2 mm length) were cannulated at each end in a perfusion chamber (Living Systems Instrumentation, St. Albans, VT). Experiments were performed using a physiological saline solution (PSS) which contained (in mmol/L): 112 NaCl, 4.8 KCl, 24 NaHCO₃, 1.8 CaCl₂, 1.2 MgSO₄, 1.2 KH₂PQ₄ and 10 glucose that was gassed with 21% O₂, 5% CO₂ and 74% N₂. The endothelium was denuded by introducing air bubbles into the vessel lumen for ~1 minute followed by wash with PSS. The chamber was continuously perfused with PSS and maintained at 37 °C. Intravascular pressure was measured using a transducer. Arterial diameter was measured using a CCD camera attached to a Nikon TS100-F microscope and the edge-detection function of IonWizard (Ionoptix, Milton, MA). Myogenic tone (%) was calculated as: 100 × (1 – D_active/D_passive), where D_active is active arterial diameter and D_passive is the diameter determined in Ca²⁺-free PSS supplemented with 5 mmol/L EGTA.