Prolactin pulsatile characteristics in postmenopausal women.

Pulsatile PRL secretion undergoes diurnal variation, with maximal PRL release in the evening during sleep in both women and men. However, the impact of the menopause on PRL pulsatile dynamics are largely unknown. To characterize diurnal PRL pulsatile secretion in postmenopausal women, we performed frequent venous sampling over 24 h every 10 min for serum PRL in 7 postmenopausal women (age, 56 +/- 4 yr) and in 2 control groups, 8 men (age, 25 +/- 8 yr) and 22 cycling women (age, 28 +/- 5 yr), at 3 phases of the menstrual cycle.

The effects of estrogen administration on trabecular bone loss in young women with anorexia nervosa.

To study the effects of prolonged anorexia nervosa on bone density (BD) and to determine whether estrogen administration prevents bone loss in women with this disorder, 48 amenorrheic women with anorexia nervosa (mean age, 23.7 yr) were randomized to receive estrogen and progestin replacement (n = 22) or no replacement (n = 26). Clinical variables, biochemical indices, and spinal trabecular BD were measured every 6 months for a mean of 1.

Progressive trabecular osteopenia in women with hyperprolactinemic amenorrhea.

Reductions in cortical and trabecular bone mass have been documented in young women with hyperprolactinemic amenorrhea. It is unknown whether trabecular osteopenia is progressive or reversible with treatment of hyperprolactinemia. In addition, it is not known whether clinical or hormonal variables can predict trabecular bone density (BD) changes.

Osteopenia in women with hypothalamic amenorrhea: a prospective study.

Hypothalamic amenorrhea, a common disorder associated with abnormalities in gonadotropin pulsatility and subsequent estrogen deficiency, is usually transient, and treatment indications are unclear unless fertility is desired. To determine whether this disorder is associated with progressive bone loss, we studied 24 women with primary or secondary amenorrhea related to stress or simple weight loss, compared with 31 normal women of the same age. Amenorrheic women had significantly lower (P = .

Mechanisms of osteoporosis in adult and adolescent women with anorexia nervosa.

Osteoporosis is a known consequence of anorexia nervosa (AN) in adults, but the mechanism of bone loss is not established, and there have been no studies of bone mass in women developing AN before attaining peak bone mass. To investigate the causes of bone loss in AN and to determine the consequences of developing AN during adolescence on bone mass, we compared the effects of AN on cortical and trabecular bone in 26 women with AN (19 adults, 18-42 yr old, and 7 adolescents, 14.9-17.

Effects of prolactin and estrogen deficiency in amenorrheic bone loss.

To determine whether hyperprolactinemic women with menses are at risk for the development of osteopenia and to define the effects of PRL excess and estrogen deficiency on bone mass in amenorrheic women, spinal and radial bone densities were measured in 25 hyperprolactinemic women (13 with amenorrhea and 12 with regular menstrual periods) and 11 women with hypothalamic amenorrhea. The degree of hyperprolactinemia was comparable in the hyperprolactinemic women with and without menstrual periods [mean, 55 +/- 18 (+/- SD) and 57 +/- 16 micrograms/L, respectively]. The mean spinal bone density in the hyperprolactinemic amenorrheic women (148 +/- 26 mg/K2HPO4.

Methimazole pharmacology in man: studies using a newly developed radioimmunoassay for methimazole.

A RIA for the antithyroid drug methimazole [1-methyl-2-mercaptoimidazole (MMI)] has been developed. A MMI derivative, 5-COOH-MMI, was conjugated to porcine thyroglobulin, and antibodies to the conjugate were raised in rabbits. [35S]MMI was used as the tracer.

Methimazole pharmacology in the rat: studies using a newly developed radioimmunoassay for methimazole.

Methimazole [1-methyl-2-mercaptoimidazole (MMI)] was given to normal male rats in their drinking water in concentrations ranging from 0.0001-0.05% for either 1 week or 1 month.

Propylthiouracil (PTU) pharmacology in the rat. II. Effects of PTU on thyroid function.

Using a sensitive and specific RIA for propylthiouracil (PTU), we examined the effects of short term (1 week) and long term (1 month) PTU treatment on thyroid function in the rat, and correlated changes in thyroid function with serum and thyroid PTU levels. After 1 week, dose-dependent decreases in thyroid PBI, serum T4, and serum T3 were observed, with concomitant elevations in the serum rT3 to T4 ratio and serum TSH. Fifty percent suppression of thyroid PBI occurred at a PTU concentration in the drinking water of 0.

Propylthiouracil (PTU) pharmacology in the rat. I. Serum and thyroid PTU measurements by radioimmunoassay.

We have developed a highly sensitive and specific RIA for propylthiouracil (PTU) which uses 125I-labeled PTU as the radioactive ligand. At a final antibody dilution of 1:10,000, the detection limit for PTU was 100 pg; cross-reactivity with circulating, urinary, and intrathyroid PTU metabolites was negligible. Using this assay, serum and thyroid PTU levels were determined after short term (1 week) and long term (1 month) PTU treatment at doses of 0.

The effect of amoxapine and imipramine on serum prolactin levels.

The effect of traditional tricyclic antidepressants on serum prolactin levels is controversial. In a five-week double-blind study of depressed outpatients, imipramine hydrochloride therapy did not lead to any significant change in serum prolactin levels. In contrast, amoxapine, a new antidepressant, produced significant elevations in serum prolactin levels in female and in male patients.