Henning Djursing

Gonadotropin secretion before and during acute and chronic dopamine-receptor blockade in insulin-dependent diabetic patients with amenorrhea*

The dopaminergic influence on luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL) was studied in 12 diabetic patients with amenorrhea (DMAM) and in 10 normal menstruating diabetic patients (DM). DMAM patients had a reduction in LH pulsatility (P less than 0.05) and basal LH levels (P less than 0.02), compared with DM patients, whereas they had an LH and FSH response to intravenous metoclopramide (MTC) at 30, 45, and 60 minutes and at 30 minutes, respectively (P less than 0.05). Basal (P less than 0.05) and MTC-stimulated (P less than 0.05) PRL levels were lower in DMAM than in DM patients. Serum PRL and FSH increased significantly (P less than 0.02) in six DMAM patients during 10 weeks of oral MTC administration, whereas no significant (P greater than 0.05) alterations occurred in serum LH and estradiol levels. These data point toward increased dopaminergic activity in DMAM patients.

Preserved Prolactin Fluctuations and Response to Metoclopramide in Ovulatory, Infertile, Hyperprolactinemic Women

Abstract. The study included 18 infertile, hyperprolacti‐nemic women with preserved menstrual cycles. Among 13 women with consistently elevated prolactin (PRL) levels, 6 had either anovulatory cycles or luteal insufficiency, whereas 7 had apparently normal ovulatory cycles. Comparisons of these two groups showed that basal levels were similar but the PRL response to metoclopramide (MTC) and the day‐to‐day fluctuations were significantly lower in the group with altered oyulatory function. In this group the PRL response to MTC was significantly greater than in control patients with hyperprolactinemic amenorrhea (n = 12), but lower than in normal women (n = 10). The PRL response to MTC in hyperprolactinemic women with normal ovulatory function did not differ significantly from that of normal women, irrespective of whether hyperprolactinemia was sustained (n = 7) or intermittent (n = 5).

Abnormal conjugated dopamine levels in patients with normoprolactinaemic amenorrhoea and in insulin-dependent diabetic patients

We determined the circulating dopamine levels in 17 patients with insulin-dependent diabetes mellitus (IDDM), of whom eight had amenorrhoea (DM-AM) and nine were normally menstruating (DM). Seven non-diabetic women with normoprolactinaemic, normogonadotrophic secondary amenorrhoea (AM) and nine normally menstruating women (controls) were studied. In all subjects basal blood concentrations of free dopamine (f-DA), conjugated dopamine (c-DA), epinephrine (E), norepinephrine (NE), prolactin (PRL), luteinizing hormone (LH), thyroid-stimulating hormone (TSH) and oestradiol-17 beta were determined and all subjects, except for three AM patients, had a Metoclopramide test performed for measurements of f-DA, c-DA, PRL, LH and TSH. Plasma c-DA was significantly (p less than 0.05) increased in patients with amenorrhoea compared to the respective control groups. In diabetic patients c-DA levels were significantly (p less than 0.05) lower compared to controls. The ratio between basal f-DA and c-DA concentrations was significantly (p less than 0.01) higher in diabetic patients compared with non-diabetic patients. After Metoclopramide stimulation DM-AM patients showed a significant (p less than 0.05) rise in c-DA, whereas this was not seen in other groups. DM-AM patients had significantly (p less than 0.05) lower basal PRL and LH levels than DM patients and controls. In addition DM-AM patients had a significantly (p less than 0.05) lower PRL response to Metoclopramide compared with DM patients. There were no significant correlations between catecholamines and basal as well as Metoclopramide stimulated pituitary hormones. This study suggests that the abnormal pituitary hormone secretion in patients with amenorrhoea may in part be caused by an increased dopaminergic activity.(ABSTRACT TRUNCATED AT 250 WORDS)