Feeding patterns in a small-bodied nocturnal folivore (Avahi laniger) and the influence of leaf chemistry: a preliminary study.

We present data on feeding patterns in Avahi laniger and compare these data to temporal variations in leaf chemistry. Because A. laniger is one of the smallest folivorous primates and has a monogastric stomach, we hypothesized that this lemur would display behavioural adaptations to a leaf-based diet by scheduling feeding times when leaves were of highest quality. Data were collected from May to August 2004 at the Vatoharanana site in Ranomafana National Park, Madagascar. A. laniger fed during different time periods despite leaf carbohydrate and protein concentrations exhibiting little variation throughout the night. Although tannin concentrations exhibited temporal fluctuations, they did not covary with A. laniger feeding times. We suggest that A. laniger feeding times cannot be explained entirely by variations in leaf chemistry.

Novel (2E,4E,6Z)-7-(2-alkoxy-3,5-dialkylbenzene)-3-methylocta-2,4,6-trienoic acid retinoid X receptor modulators are active in models of type 2 diabetes.

Previous data have shown that RXR-selective agonists (e.g., 3 and 4) are insulin sensitizers in rodent models of non-insulin-dependent diabetes mellitus (NIDDM). Unfortunately, they also produce dramatic increases in triglycerides and profound suppression of the thyroid hormone axis. Here we describe the design and synthesis of new RXR modulators that retain the insulin-sensitizing activity of RXR agonists but produce substantially reduced side effects. These molecules bind selectively and with high affinity to RXR and, unlike RXR agonists, do not activate RXR homodimers. To further evaluate the antidiabetic activity of these RXR modulators, we have designed a concise and systematic structure-activity relationship around the 2E,4E,6Z-7-aryl-3-methylocta-2,4,6-trienoic acid scaffold. Selected compounds have been evaluated using insulin-resistant rodents (db/db mice) to characterize effects on glucose homeostasis. Our studies demonstrate the effectiveness of RXR modulators in lowering plasma glucose in the db/db mouse model.