The role of dopamine and serotonin in regulating bone mass and strength: studies on dopamine and serotonin transporter null mice.

Neurotransmitter regulation of bone metabolism has been a subject of increasing interest and investigation. Dopamine (DA) has been reported to have effects on calcium and phosphorus metabolism. The dopamine transporter (DAT) is believed to control the temporal and spatial activity of released DA by rapid uptake of the neurotransmitter into presynaptic terminals.

The role of strain in the response of rapidly growing young male rat bones to parathyroid hormone.

Human parathyroid hormone (hPTH 1-34) stimulates an anabolic response in human and animal skeletons; however, it is unclear if the effect is strain dependent. To determine if the anabolic response to hPTH (1-34) was dependent upon strain in rats we used 2 outbred strains (Sprague Dawley, Wistar), 2 inbred strains (Fischer 344, Wistar spontaneously hypertensive:SHR), and 2 mutant strains (Zucker obese, Zucker lean) of rats. Male rats, 5 weeks of age, from each strain were treated subcutaneously with 80 microg/kg body weight hPTH (1-34) or vehicle for 12 days.

Possible mechanisms of osteopenia in Rett syndrome: bone histomorphometric studies.

The etiology of frequently occurring osteoporosis in Rett syndrome is unknown. Five girls, ages 9.75, 11, 12, 13.

Bone histomorphometry in three females with Rett syndrome.

The frequent occurrence of osteoporosis in Rett syndrome raises questions about the etiology of this finding. It is unknown whether there is any relationship between low bone mass and the underlying genetic disorder. We recently had an opportunity to study the status of bone remodeling by quantitative bone histomorphometry in three girls ages 9.

Phenotypic characterization of mice bred for high and low peak bone mass.

In humans, peak bone mineral density (BMD) is a highly heritable trait and a strong determinant of subsequent osteoporotic fracture risk. To identify the genetic factors responsible for variation in peak BMD, investigators have turned to animal models. In this study we examined the heritability of BMD acquisition and characterized differences in skeletal geometry, histomorphometry, and biomechanical competence between two lines of mice artificially selected for extremes of peak whole body BMD.