Prolactin response induced by ECT and TRH

Prolactin and TSH responses to TRH and to ECT in pre- and postmenopausal women with major depression

The patterns of prolactin and thyrotropin (TSH) release after thyrotropin-releasing hormone (TRH) (0.4 mg i.v.) and during the first session of a course of electroconvulsive treatment (ECT) were studied in women with major depression, 16 in pre- and 29 in postmenopausal status. The prolactin responses to both stimuli were lower in postmenopausal women, whereas the TSH responses were not different. The known correlation between the maximal prolactin response to ECT and the maximal response to TRH was significantly stronger in the group of premenopausal women (r = .8648, versus .4249 in the postmenopausal group, p < .02). A common underlying mechanism promoting prolactin release for both stimuli can be suggested, which diminishes after menopause, probably an influence of estradiol on the affinity of dopaminergic and serotonergic receptors. That mechanism does not interfere with the TSH release either by ECT or by TRH.

Effects of thyrotropin-releasing hormone administration on the electroconvulsive therapy induced prolactin responses and seizure time

The effects of thyrotropin-releasing hormone (TRH) administration on electroconvulsive therapy (ECT)-induced prolactin (PRL) secretion and the duration of the seizure were studied in 14 depressed women. In a balanced order crossover design the patients were given 0.4 mg TRH or placebo intravenously 20 min before ECT during the first two sessions. In the third ECT session TRH was given just prior to ECT. ECT elicited the expected PRL response when given alone and when given 20 min after TRH when PRL plasma levels were high. During the coadministration design (third ECT session) PRL levels were raised not as a sum of the two stimuli but even significantly more. TRH failed to modify the duration of the seizure induced by ECT. Therefore, if TRH is involved in seizure modulation during ECT, our findings suggest a postictal rather than ictal role for TRH.

Prolactin in patients with major depressive disorder and in healthy subjects. I. Cross-sectional study of basal and post-TRH and postdexamethasone prolactin levels

Prolactin (PRL) levels were investigated in patients with major depressive illness and in healthy subjects. Basal and postdexamethasone levels were measured in 27 patients, and levels after thyrotropin-releasing hormone (TRH) stimulation (delta PRL) were measured in 22 patients. Basal and delta PRL were also determined in 64 age- and sex-matched healthy subjects. Both basal and postdexamethasone PRL levels were normal in depressed patients, with the postdexamethasone levels in particular showing no correlation to postdexamethasone cortisol concentrations. One milligram oral dexamethasone did not influence 4:00 PM PRL levels in 15 healthy subjects. delta PRL was significantly elevated in both male and female patients. These increases were not correlated with severity of illness and are difficult to interpret owing to the complexity of the PRL regulatory system. No significant correlations were found between basal or post-TRH PRL and cortisol, thyroid-stimulating hormone (TSH), thyroid hormones, gonadotropins, or estradiol in the patients. However, surprisingly significant positive correlations between basal PRL and basal cortisol, T4 and reverse T3 occurred in healthy subjects. It is as yet unclear how this finding can be explained and what relevance it has. Women tended to have higher basal PRL concentrations than men, but the difference was not significant in either group. delta PRL was significantly higher in women than in men in both patients and controls. No significant influence of age was found.

The patterns of prolactin release by ECT and TRH compared

The patterns of prolactin release after bilateral ECT and after 0.4 mg TRH i.v. were studied in 11 female melancholic patients in a 5-min sampling protocol. Mean prolactin peaking times were 10.2 min after ECT and 20.5 min after TRH. The elimination rate coefficients were significantly lower--and the corresponding half-lives longer--for prolactin released by TRH than by ECT. A significant positive correlation of the maximal prolactin responses by the two stimuli was also found.