Inclusion Criteria:

- Female volunteers in early to midpuberty (i.e., late Tanner I [estradiol level > 20
pg/mL], Tanner II, or Tanner III)

- Premenarcheal

Exclusion Criteria:

- Pregnancy

- Inability to comprehend what will be done during the study or why it will be done

- Hemoglobin less than 12 g/dl and hematocrit less than 36%

- Persistently abnormal sodium, potassium, or bicarbonate (i.e., confirmed on repeat)

- Persistently elevated creatinine, hepatic transaminases, or alkaline phosphatase
(i.e., confirmed on repeat)

- Total bilirubin > 1.5 times upper limit of normal (i.e., confirmed on repeat)

- Significant history of cardiac or pulmonary dysfunction (e.g., known or suspected
congestive heart failure; asthma requiring intermittent systemic corticosteroids;
etc.)

- Untreated hypo- or hyperthyroidism (reflected by persistently abnormal TSH values)

- Total testosterone > 200 ng/dl

- Basal (follicular) 17-OHP > 200 ng/ml (in girls without a previous diagnosis of
congenital adrenal hyperplasia)

- DHEA-S > 800 mcg/dl

- Elevation of prolactin > 2 times upper limit of normal

- Weight less than 26 kg.