Late preconditioning induced by NO donors, adenosine A1 receptor agonists, and delta1-opioid receptor agonists is mediated by iNOS.

Although ischemia-induced late preconditioning (PC) is known to be mediated by inducible nitric oxide (NO) synthase (iNOS), the role of this enzyme in pharmacologically induced late PC remains unclear. We tested whether targeted disruption of the iNOS gene abrogates late PC elicited by three structurally different NO donors [diethylenetriamine/NO (DETA/NO), nitroglycerin (NTG), and S-nitroso-N-acetyl-penicillamine (SNAP)], an adenosine A1 receptor agonist [2-chloro-N6-cyclopentyladenosine (CCPA)], and a delta1-opioid receptor agonist (TAN-670). The mice were subjected to a 30-min coronary occlusion followed by 24 h of reperfusion.

Protease-activated receptor and endothelial-myocyte uncoupling in chronic heart failure.

We examined the hypothesis that oxidants generated nitroso derivatives, activated latent matrix metalloproteinase (MMP), and induced proteinase-activated receptor 1 (PAR-1), leading to disconnection between the endothelium and myocytes. Administration of cardiospecific tissue inhibitor of metalloproteinase-4 (TIMP-4/CIMP) ameliorated the oxidative-proteolytic stress and endothelial-myocyte uncoupling in chronic heart failure (CHF) in mice. Aortic-vena cava fistula (AVF) was created in 30 male mice (C57BL/6J) and studied at 0-, 2-, and 8-wk AVF.

Enhanced rat beta-cell proliferation in 60% pancreatectomized islets by increased glucose metabolic flux through pyruvate carboxylase pathway.

Islet beta-cell proliferation is a very important component of beta-cell adaptation to insulin resistance and prevention of type 2 diabetes mellitus. However, we know little about the mechanisms of beta-cell proliferation. We now investigate the relationship between pyruvate carboxylase (PC) pathway activity and islet cell proliferation 5 days after 60% pancreatectomy (Px).

Prejunctional modulation of norepinephrine release in the human iris-ciliary body.

Purpose: To characterize the prejunctional mechanisms that control the impulse-evoked release of norepinephrine in the isolated, superfused human iris-ciliary body.

Methods: Human iris-ciliary body tissue segments were preincubated with 3H-norepinephrine, superfused and electrically-stimulated in vitro to evoke the discharge of 3H-norepinephrine. The effects of prejunctional modulators on evoked 3H-norepinephrine overflow were evaluated.

Physical properties of a periodontal dressing material.

Further characterization has been undertaken of a visible light cured periodontal dressing material (Barricaid), which has been shown to exhibit superior physical properties to those of the standard (chemically curing) dressing materials. In particular, water sorption and solubility were studied, with a greater solubility found at 37 degrees than at 23 degrees with little further increase at 50 degrees C. Water sorption increased from 23 degrees C to 37 degrees C but decreased at 50 degrees C.