Molecular determinants of energy homeostasis

Minireview: the year in review of estrogen regulation of metabolism

Gonadal steroids are critical regulators of physiology, yet we approach physiology and science with the simplest perspective/model, the male one. Female models of whole animal physiology are complex to study and, therefore, are often not used in research. Estrogens are one of the sex hormones that we know are important for both men and women. Estrogens regulate key features of metabolism such as food intake, body weight, glucose homeostasis/insulin sensitivity, body fat distribution, lipolysis/lipogenesis, inflammation, locomotor activity, energy expenditure, reproduction, and cognition. Furthermore, estrogens have multiple sites of action including some unexpected ones, which was demonstrated elegantly through a series of papers this year.

Role of hypothalamic melanocortin system in adaptation of food intake to food protein increase in mice

The hypothalamic melanocortin system—the melanocortin receptor of type 4 (MC4R) and its ligands: α-melanin-stimulating hormone (α-MSH, agonist, inducing hypophagia), and agouti-related protein (AgRP, antagonist, inducing hyperphagia)—is considered to play a central role in the control of food intake. We tested its implication in the mediation of the hunger-curbing effects of protein-enriched diets (PED) in mice. Whereas there was a 20% decrease in food intake in mice fed on the PED, compared to mice fed on an isocaloric starch-enriched diet, there was a paradoxical decrease in expression of the hypothalamic proopiomelanocortin gene, precursor of α-MSH, and increase in expression of the gene encoding AgRP. The hypophagia effect of PED took place in mice with invalidation of either MC4R or POMC, and was even strengthened in mice with ablation of the AgRP-expressing neurons. These data strongly suggest that the hypothalamic melanocortin system does not mediate the hunger-curbing effects induced by changes in the macronutrient composition of food. Rather, the role of this system might be to defend the body against the variations in food intake generated by the nutritional environment.

Long-term use of pramipexole in bipolar depression: a naturalistic retrospective chart review

A naturalistic retrospective chart review of all patients given pramipexole for bipolar depression in addition to their mood stabilizers was undertaken. Sixteen patients were followed for an average of 6.7 +/- SD 9.0 months. Half of the patients stopped the pramipexole an average of 2 months after starting it. For all patients, depressed mood, and the total profile of depressive symptoms improved significantly within 4 weeks and remained significantly improved for as long as 36 weeks. Both global function (GAF), and global impression (CGI) improved with pramipexole. Irritability and insomnia both increased slightly initially, and then subsided. There were no changes in mania ratings for up to 36 months. Long-term outcome of adjunctive pramipexole appears to be adequate, with apparent maintenance of effect for over 9 months.