Effects of estrous cycle and steroid replacement on the expression of leptin and uncoupling proteins in adipose tissue in the rat.

Among other actions, leptin has been suggested to increase energy expenditure and to modulate the menstrual cycle. In fact, the main effect of leptin seems to be modulating the sympathetic nervous system and gonadotropin-releasing hormone pulsatility. We investigated whether changes in the plasma steroid concentrations during the estrous cycle and after ovariectomy and steroid replacement can modulate plasma leptin levels, adipose tissue leptin mRNA expression, and some of the candidates for mediating energy expenditure (uncoupling proteins (UCP) 1, 2, and 3 mRNA) in white and brown adipose tissue.

Effects of chronic celiprolol treatment on brown fat, feeding, and drinking in fa/fa Zucker rats.

Celiprolol is a novel beta-adrenoceptor blocking drug that displays clinically favorable effects on glucose and lipid metabolism. Because some other atypical beta-adrenoceptor blocking drugs have been described to act as agonists on beta(3)-adrenoceptors, we aimed to investigate the effects of celiprolol on brown fat and beta(3)-adrenoceptors. Chronic treatment of obese fa/fa Zucker rats with celiprolol (50 mg/kg/day orally for 20 days) increased GDP binding to brown fat mitochondria by 1.

Acute inhibition of oestrogen biosynthesis does not affect serum leptin levels in young men.

Objective: Leptin plays an important role in the regulation of reproduction. To explore the contribution of oestradiol to serum leptin levels in men, we measured the concentrations of serum leptin and insulin after inhibition of oestrogen biosynthesis by selective blockade of the aromatase enzyme.

Design: The study had a double-blind parallel group design.

Inverse correlation between serum testosterone and leptin in men.

Besides its role in the regulation of energy balance, leptin seems to be involved in linking energy stores to the reproductive system. A gender-dependent difference exists in plasma leptin concentration and leptin messenger ribonucleic acid expression in rodents and humans. This difference does not seem to be explained simply by differences in the amount of body fat between genders.

Correlation between circulating leptin and luteinizing hormone during the menstrual cycle in normal-weight women.

Objective: Leptin is the hormonal product of the ob gene. It is expressed in adipocytes and participates in the regulation of food intake and metabolism. Since leptin also seems to signal metabolic information to the reproductive system, we studied the association between reproductive hormones and plasma leptin in normal-weight young women.