Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels. Force-tension myography demonstrates that vessels from Opn4 −/− mice fail to display photorelaxation, which is also inhibited by an Opn4-specific small-molecule inhibitor. The vasorelaxation is wavelength-specific, with a maximal response at ∼430-460 nm. Photorelaxation does not involve endothelial-, nitric oxide-, carbon monoxide-, or cytochrome p450-derived vasoactive prostanoid signaling but is associated with vascular hyperpolarization, as shown by intracellular membrane potential measurements. Signaling is both soluble guanylyl cyclase-and phosphodiesterase 6-dependent but protein kinase G-independent. β-Adrenergic receptor kinase 1 (βARK 1 or GRK2) mediates desensitization of photorelaxation, which is greatly reduced by GRK2 inhibitors. Blue light (455 nM) regulates tail artery vasoreactivity ex vivo and tail blood blood flow in vivo, supporting a potential physiological role for this signaling system. This endogenous opsin-mediated, lightactivated molecular switch for vasorelaxation might be harnessed for therapy in diseases in which altered vasoreactivity is a significant pathophysiologic contributor.hotorelaxation, the reversible relaxation of blood vessels to cold light, was initially described by Furchgott et al. in 1955 (1). Subsequent studies have attempted to define the signal transduction mechanisms responsible for this phenomenon. The process seems to be cGMP-dependent but endothelialindependent. The role of nitric oxide (NO) in photorelaxation has been controversial (2-7), with some studies showing that NOS inhibition with L-NAME not only fails to inhibit the response (2) but in some cases enhances and prolongs it (3). Moreover, several published reports examining photorelaxation demonstrate an attenuation of the response with each subsequent light stimulation. A number of investigators have proposed that NO dependence results from the photo-release of NO stores from nitrosothiols and that the endothelium and NOS are important for the repriming of these stores (stores that become depleted with each photo-stimulation); however, the source of those nitrosothiols has not as yet been clearly identified (6). Importantly, photo-release of NO occurs in the UV-A spectrum at 366 nm (4-6), a wavelength at which intravascular nitrosospecies and nitrite have the potential to release substantial quantities of NO (7). However, this wavelength is very different from that at which others have observed vascular responses. Given the controversy surrounding the photorelaxation mechanism, we postulated an entirely new mechanism: that photorelaxation i...

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BackgroundFor ophthalmic surgery anesthesia, it is vital that intraocular pressure (IOP) is controlled. Most anesthetic drugs affect IOP dose-dependently, and inhalational anesthetics dose-dependently decrease IOP. In this study, we compared the effects of desflurane and sevoflurane on IOP and hemodynamics in pediatric ophthalmic surgery.MethodsThirty eight pediatric patients from the age of 6 to 15 years, who were scheduled for strabismus surgery and entropion surgery, were randomized to be administered desflurane (group D, n = 19) or sevoflurane (group S, n = 19). IOPs and hemodynamic parameters were measured before induction of anesthesia (B), after induction but immediately before intubation (AI), 1 min after intubation (T1), 3 min after intubation (T3), and 5 min after intubation (T5).ResultsThe mean arterial pressure (MAP) at T1 and heart rates (HRs) at T1 and T3 were significantly higher in group D than those in group S. There was no significant difference between the groups in IOP, cardiac index (CI) and stroke index (SI). There was a significant difference within the group in IOP, SI, MAP and HR. There was no significant difference within the group in CI.ConclusionsThere was no significant difference between the groups in IOP and hemodynamic parameters. The two anesthetic agents maintained IOP and hemodynamic parameters in the normal range during anesthetic induction.

Endometriosis, defined as growth of endometrial stroma and glands outside the uterine cavity, is a chronic and recurrent disease that affects patients' quality of life. Ectopic endometrial tissue can proliferate at any location in the body, but the pelvic organs and peritoneum are the most frequent implantation sites. Among extrapelvic endometriosis, inguinal endometriosis is a very rare gynecologic condition usually associated with previous pelvic surgery. Endometriosis should be preoperatively distinguished from other inguinal masses using computed tomography, magnetic resonance imaging, or ultrasonography. Here, we report a case of right inguinal endometriosis in a patient with no previous history of gynecologic surgery; in addition, we have provided a brief review of relevant literature.