“
“Please cite this paper as: Gaynes B, Teng P-Y, Wanek J, Shahidi M. Feasibility of conjunctival hemodynamic measurements in rabbits: reproducibility, Sirolimus in vitro validity, and response to acute hypotension. Microcirculation 19: 521–529, 2012. Objective:  To evaluate the feasibility of conjunctival hemodynamic measurements based on assessment of reproducibility, validity, and response to acute hypotension. Methods:  Image sequences of the conjunctival microvasculature of rabbits were captured using a slit lamp biomicroscope under a steady-state condition, after topical administration of phenylephrine, and after intravenous administration of esmolol. Venous hemodynamic parameters (diameter, blood velocity,

blood flow, and wall shear stress) were derived. Results:  Conjunctival venous diameters ranged from 9 to 34 μm and blood velocities ranged MK-8669 research buy from 0.08 to 0.95 mm/s. Coefficients of variation of venous diameter and blood velocity measurements were, on average, 6% and 14%, respectively. Automated and manual measurements of venous diameter and velocity were highly correlated (R = 0.97; p < 0.001; n = 16). With phenylephrine administration, diameter and velocity were reduced by 21% and 69%, respectively. Following esmolol administration, blood pressure was reduced with a concomitant decrease in velocity, followed by recovery to baseline. Venous blood velocity, flow, and WSS were correlated with blood pressure (R ≥ 0.52; p ≤ 0.01). Conclusions: 

The feasibility of quantifying alterations in microvascular hemodynamics in the bulbar conjunctiva was established. The method is of potential value in evaluating microcirculatory hemodynamics related to cardiovascular function. “
“Please cite this paper as: Adderley, Sridharan, Bowles, Stephenson, Sprague and Ellsworth (2011). Inhibition of

ATP Release from Erythrocytes: A Role for EPACs and PKC. Microcirculation18(2), 128–135. Objective:  Here we demonstrate that, in human erythrocytes, increases in cAMP that are Montelukast Sodium not localized to a specific receptor-mediated signaling pathway for ATP release can activate effector proteins resulting in inhibition of ATP release. Specifically we sought to establish that exchange proteins activated by cAMP (EPACs) inhibit ATP release via activation of protein kinase C (PKC). Methods:  ATP release stimulated by iloprost (ILO), or isoproterenol (ISO), was determined in the absence and presence of selective phosphodiesterase inhibitors and/or the EPAC activator, 8CPT2OMecAMP (8CPT). To determine whether EPACs inhibit ATP release via activation of PKC, erythrocytes were incubated with phorbol 12-myristate 13-acetate (PMA) prior to either forskolin or ILO in the absence and presence of a PKC inhibitor, calphostin C (CALC). Results:  Selective inhibition of PDEs in one pathway inhibited ATP release in response to activation of the other cAMP-dependent pathway. 8CPT and PMA inhibited both ILO- and ISO-induced ATP release.