Ethnic and gender differences in advanced glycation end products measured by skin auto-fluorescence.

Advanced glycation end products (AGEs) have been shown to be a predictor of cardiovascular risk in Caucasian subjects. In this study we examine whether the existing reference values are useable for non-Caucasian ethnicities. Furthermore, we assessed whether gender and smoking affect AGEs. Methods: AGEs were determined by a non-invasive method of skin auto-fluorescence (AF). AF was measured in 200 Arabs, 99 South Asians, 35 Filipinos and 14 subjects of other/mixed ethnicity in the Qatar Metabolomics Study on Diabetes (QMDiab). Using multivariate linear regression analysis and adjusting for age and type 2 diabetes, we assessed whether ethnicity, gender and smoking were associated with AF. Results: The mean AF was 2.27 arbitrary units (AU) (SD: 0.63). Arabs and Filipinos had a significant higher AF than the South Asian population (0.25 arbitrary units (AU) (95% CI: 0.11*0.39), p = 0.001 and 0.34 (95% CI: 0.13*0.55), p = 0.001 respectively). Also, AF was significantly higher in females (0.41 AU (95% CI: 0.29*0.53), p 0.001). AF associated with smoking (0.21 AU (95% CI: 0.01*0.41), p = 0.04) and increased with the number of pack-years smoked (p = 0.02). Conclusions: This study suggests that the existing reference values should take ethnicity, gender and smoking into account. Larger studies in specific ethnicities are necessary to create ethnic-and gender-specific reference values

Pharmacological examination of contractile responses of the guinea-pig isolated ileum produced by μ-opioid receptor antagonists in the presence of, and following exposure to, morphine

1. We have assessed the potential of several μ-opioid receptor antagonists to elicit a response in the guinea-pig isolated ileum in the presence of, and following overnight exposure to, morphine. 2. Naloxone, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP), (−)-5,9α-diethyl-2-(3-furyl-methyl)-2′-hydroxy-6,7-benzomorphan (MR2266), but not D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP), produced a transient inhibition of electrically-evoked contractions of the guinea-pig ileum. The effect of 1 μM CTOP, but not that to MR2266, was inhibited by 1 μM somatostatin. 3. Naloxone (0.3 μM), CTOP (3 μM), CTAP (3 μM) and MR2266 (0.3 μM) antagonized the inhibitory effect of morphine on electrically-evoked contractions of the guinea-pig to a similar degree and, following 60 min exposure to morphine, produced non-sustained contractions. The response to 3 μM CTOP was significantly smaller than that to 3 μM CTAP. None of the antagonists produced a response in the absence of morphine. 4. Following overnight exposure of the ileum to 0.3 μM morphine (4°C), and repeated washing to remove the agonist, all four antagonists elicited non-sustained contractions. However, the responses to 3 μM CTOP and 0.3 μM MR2266 were significantly smaller than those elicited by 0.3 μM naloxone and 3 μM CTAP. Somatostatin (1 μM) significantly reduced naloxone-induced contractions, but not those to CTAP. 5. While all four μ-opioid antagonists elicited contractions in the presence of, and following prolonged exposure to, morphine, differences between them were noted which may be a consequence of non-opioid actions