Abnormal serotonergic control of prolactin and cortisol secretion in patients with seasonal affective disorder

The effects of the serotonergic agent d,l-fenfluramine (60 mg PO) or a placebo on serum prolactin (PRL) and cortisol levels were evaluated in seven patients (five men and two women) with seasonal affective disorders (SAD) and in eight normal controls (eight men and two women). Both groups were tested in fall/winter when patients with SAD suffered depressive symptoms and in spring/summer, when patients were euthymic. Spring/summer and fall/winter tests gave similar results. PRL and cortisol patterns were similar in all subjects after placebo, whereas both hormonal responses to d,l-fenfluramine were significantly lower in patients with SAD than in normal controls. Correlation studies between the two hormonal responses revealed that on both periods the amplitudes of PRL and cortisol increments were significantly and positively correlated in patients with SAD. These data show diminished serotonergic responsiveness in SAD regardless of the actual depressive status of the patients. They are consistent with a decrease of central serotonergic activity in SAD.     

焦虑症的生化病理机制探讨

目的：从神经递质与神经内分泌角度探讨焦虑症的生化病理机制。方法：采用高效液相色谱法及放射免疫测定法，分别测定25例焦虑症患者和28例正常对照者血小板5—羟色胺(5—HT)含量及血浆催乳素(PRL)含量、地塞米松抑制实验(DST)皮质醇含量。结果：广泛性焦虑(GAD)组血小板5—HT水平高于正常对照组，惊恐障碍(PD)组与正常对照组无显著差异；GAD组与对照组血浆PRL均极显著低于PD组；GAD组与PD组血浆基础皮质醇含量均显著高于正常对照组，两组DST阳性率均为20％，正常对照组为14．3％，3组阳性率无显著性差异；汉密尔顿焦虑量表(HAMA)评分与血浆皮质醇浓度呈显著正相关。结论：焦虑症患者存在神经递质和神经内分泌功能的紊乱，但不同亚型间可能存在不同的病理机制，皮质醇浓度可能是焦虑水平的标志因子。     

Plasma cortisol, prolactin, growth hormone, and immunoreactive beta-endorphin response to fenfluramine challenge in depressed patients

The effect of a single dose (60 mg p.o.) of the serotonin agonistic agent fenfluramine (FNF) on plasma cortisol, prolactin (PRL), growth hormone (GH), and immunoreactive beta-endorphin (ir-beta-EP) levels was assessed in eight major depressed patients and eight controls. The hormones were monitored at basal level (0') and hourly during 5 h following FNF administration. The pharmacological challenge caused an elevation of 80% in PRL secretion in the healthy controls and only 42% in the depressed patients. However, the actual prolactin response (delta max) failed to discriminate depressed patients from controls. A blunted response followed by a decrease (33%) in serum cortisol levels was observed in depressed patients 5 h after drug administration while an increase of 94% was obtained in controls after 3 h. FNF provocation did not affect GH and ir-beta-EP plasma levels. The blunted cortisol responsiveness to FNF administration in depressed patients may reflect functional hypoactivity of central serotonergic system at least during the acute phase of major depression. It is not clear why the cortisol hyporesponsivity in depressed patients is not accompanied by a similar reduced PRL response to FNF challenge.     

The effects of intraventricular prolactin infusions on pituitary responsiveness to thyrotropin-releasing hormone, 5-hydroxytryptophan or morphine in rhesus monkeys

The effects of intraventricular infusions of ovine prolactin (oPrl) on both endogenous prolactin levels in serum, and upon the release of prolactin and cortisol in response to treatment with either TRH, 5-HTP or morphine were studied in rhesus monkeys. A single injection of oPrl (10.8 μg) into the lateral ventricles of castrated males resulted in CSF levels of around 350 ng/ml 60 min later, but no oPrl could be detected in the blood. Endogenous (rhesus) prolactin levels in serum fell during this time to about half their initial values in oPrl-treated animals but not in the bovine serum albumin (BSA)-injected controls. Ovine prolactin was infused continuously into either the lateral or third ventricles of ovariectomized, estrogen-treated females for 6 days from an osmotic minipump (2.7 μg/h). CSF levels of oPrl were about 250 ng/ml though none was found in the serum. The release of endogenous prolactin by TRH (1 μg) was greatly reduced compared with BSA-treated controls. 5-HTP (2.5 mg/kg together with carbidopa pretreatment) also stimulated much less prolactin release in females chronically infused with oPrl and there was some evidence for a similar effect in males following a single intraventricular injection. CSF levels of 5-HTP itself, and of 5-HIAA and HVA were similar throughout this experiment in both oPrl and BSA-infused animals. Finally, prolactin released by morphine (5 mg) was highly attenuated in females receiving oPrl intraventricularly.In contrast to those on serum prolactin, the effects of these various treatments on serum cortisol were unaltered by intraventricular oPrl.These results suggest that the primate brain contains a neural system which is directly responsive to prolactin, and which can modulate this hormone's release under either basal conditions or following treatment with substances that stimulate its release by acting either directly on the pituitary or upon the neural systems regulating pituitary function. These results are compatible with the presence of increased dopamine in the portal blood, though this was not measured in these experiments.     

Increased serum cortisol and growth hormone levels in earthquake survivors with PTSD or subclinical PTSD

Alteration of neuroendocrine systems has been demonstrated to be involved in the pathology of posttraumatic stress disorder (PTSD). Three months after an earthquake in Northern China, cortisol, growth hormone (GH) and prolactin (PRL) levels were assessed in 34 earthquake survivors with PTSD (according to DSM-IV criteria), 30 earthquake survivors with subclinical PTSD and 34 normal controls. Only earthquake survivors diagnosed with PTSD had significantly higher serum GH levels. Also, we found that earthquake survivors (either with PTSD or subclinical PTSD) had significantly higher serum cortisol levels. We concluded that PTSD might be associated with an increased level of serum GH and traumatic survivors might be associated with a higher level of serum cortisol.     

Stimulation of serum cortisol and prolactin secretion in humans by MK-212, a centrally active serotonin agonist

The effects of MK-212 [6-chloro-2-(1-piperazinyl)-pyrazine] (10, 20, and 40 mg, orally), a centrally acting serotonin (5-HT) receptor agonist and placebo, on serum cortisol, prolactin, and growth hormone levels were studied in eight healthy men over 3-hr. MK-212 produced a dose-related increase in serum cortisol levels, with the 20- and 40-mg doses producing significant elevations. Serum prolactin levels were significantly elevated only by the 40-mg dose. Serum GH levels were not significantly modified by any dose of MK-212. The cortisol and prolactin responses to the 40-mg dose of MK-212 were positively correlated (rho = + 0.85, p less than 0.02). MK-212 was generally well tolerated by the subjects. Headache and nausea were observed at the higher doses, but did not appear to be related to the increase in serum cortisol and prolactin levels. MK-212 may stimulate the secretion of cortisol and prolactin in humans via a serotonin (5-HT2) receptor mechanism and may be a valuable tool with which to study 5-HT receptor sensitivity in humans.     

抑郁症的生化病理机制探讨

目的：从神经递质与神经内分泌角度探讨抑郁症的生化病理机制。方法：采用高效液相色谱法及放射免疫测定法，分别测定15例抑郁症患者和27例正常对照者血小板5-羟色胺（5-HT）含量及血浆催乳素（PRL）含量，地塞米松抑制实验（DST）皮质醇含量。结果：抑郁症组血小板5-HT水平低于正常对照组，血浆基础皮质醇及服地塞米松后皮质醇均高于正常对照组，DST阳性率高于正常对照组。结论：抑郁症患者存在神经递质和神经内分泌功能的紊乱，抑制症的5-HT能假说能解释其某些内分泌功能紊乱。     

Seasonal independence of low prolactin concentration and high spontaneous eye blink rates in unipolar and bipolar II seasonal affective disorder

Twenty-four subjects with seasonal affective disorder (SAD: bipolar II, n = 14; unipolar, n = 10) and 20 normal controls were assessed for early follicular basal serum prolactin (PRL) concentration in winter and summer. Luteal basal PRL concentration was assessed in winter. The PRL values represented the mean of three values derived during a 45-minute period. A subset of 17 subjects with SAD and 11 controls were also assessed for spontaneous eye blinking via a polygraphic recording in winter and summer. In winter, compared with controls, subjects with SAD were characterized by significantly lower follicular (10.1 vs 4.5 micrograms/L, respectively) and luteal (14.4 vs 7.4 micrograms/L, respectively) PRL values and by significantly higher eye blink rates (30 vs 61 blinks per 3 minutes, respectively). In summer, controls and subjects with SAD showed similar significant differences in follicular PRL values (9.3 vs 3.9 micrograms/L, respectively) and eye blink rates (25 vs 67 blinks per 3 minutes, respectively). No significant differences in PRL values or eye blink rates were found between the bipolar II and unipolar forms of SAD in either season. Results were discussed in terms of dopamine functioning.     

The effects of paroxetine and tianeptine on peripheral biochemical markers in major depression

Depression is related to the alterations of the central serotonergic system and some antidepressants achieve their therapeutic effects through alteration of serotonin (5-HT) (re)uptake. Peripheral biochemical markers, platelet and serum 5-HT concentrations, platelet monoamine oxidase (MAO) activity, plasma levels of cortisol and prolactin (PRL), were investigated in patients with major depression before and after 4 weeks of treatment with paroxetine (an inhibitor of 5-HT uptake) or tianeptine (a stimulator of 5-HT uptake). Study was open, single center and included female depressed patients, 21 treated with tianeptine (37.5 mg/day) and 15 treated with paroxetine (20 mg/day), and 11 drug-free healthy women (controls). Before treatment, depressed patients as a group had significantly higher serum 5-HT and cortisol concentrations than healthy controls. There were no differences in the other biochemical markers. Response to antidepressant treatment was estimated according to the 50% fall in the initial scores of Hamilton Depression Rating Scale (HAMD) after 4 weeks of treatment. Good therapeutic response was observed in 47% and 45% patients treated with paroxetine and tianeptine, respectively. Paroxetine treatment induced significant decrease in platelet 5-HT concentrations in both responders and nonresponders, while no alterations in platelet 5-HT values were found in tianeptine-treated patients. There was a subgroup of depressed patients in paroxetine-treated group with high pretreatment platelet 5-HT concentration and later poor therapeutic response to paroxetine treatment. Serum 5-HT values, platelet MAO activity or plasma cortisol or PRL levels were unchanged after both treatments. The results suggest that pretreatment platelet 5-HT levels, but not other peripheral biochemical markers, might predict therapeutic outcome at least in paroxetine-treated patients.     

老年抑郁症患者认知功能损害与血清皮质醇的关系研究

目的探讨老年抑郁症(LLD)患者认知功能损害与血清皮质醇水平的关系。方法纳入LLD认知损害患者35例、LLD认知正常患者14例、正常对照组25例,采用汉密尔顿抑郁量表17项版(HAMD-17)和简易智能状态评价量表(MMSE)分别评定抑郁症状和总体认知功能,采用化学发光微粒子免疫法测定血清皮质醇浓度。结果 LLD认知损害患者的血清皮质醇水平高于LLD认知正常者[(11.83±4.70)ug/d Lvs.(8.21±3.64)ug/d L,P0.01]。LLD发作期伴认知损害者[(11.6±4.6)ug/d L]、LLD恢复期伴认知损害者[(12.4±5.2)ug/d L]血清皮质醇水平均高于LLD恢复期认知正常者[(8.5±3.7)ug/d L]及正常对照组[(8.6±4.3)ug/d L](P均0.05)。结论伴有认知损害的LLD患者,无论是处于发作期还是恢复期,血清皮质醇水平均升高。皮质醇水平可能是影响LLD患者认知功能的重要因素。     

Prolactin and cortisol responses to MK-212, a serotonin agonist, in obsessive-compulsive disorder

To examine further the serotoninergic system in obsessive-compulsive disorder (OCD), the plasma concentrations of cortisol and prolactin and the behavioral responses after oral administration of MK-212 (6-chloro-2-[1-piperazinyl]-pyrazine), a serotonin agonist, and placebo were studied in 17 patients with OCD and nine normal controls. The two groups did not differ significantly in basal plasma prolactin or cortisol levels. Nevertheless, both the prolactin and cortisol response to oral administration of MK-212 (20 mg) were significantly blunted in the patients with OCD compared with those of the normal controls. MK-212 did not affect the intensity of OCD symptoms. However, MK-212, as compared with placebo, produced slight but statistically significant increases in self-ratings of nausea, dizziness, anxiety, feeling strange, and mixed feelings of calmness and restlessness, as well as depression and feeling high. These behavioral ratings were not significantly different in patients and normal controls. These findings are consistent with previous reports of diminished serotoninergic responsivity in OCD and raise the possibility of subsensitivity of at least some serotonin receptors in this disorder.     

Serum postdexamethasone prolactin measures in depressive patients and control subjects

Recently, some researchers noted significant positive relationships between postdexamethasone serum cortisol and prolactin levels, whilst endogenous depressives exhibited a significantly lower suppression of prolactin by dexamethasone than non-endogenous patients or normal controls. To ascertain the extent of prolactin responses to dexamethasone in severely depressed patients, we measured 8 a.m. pre- and postdexamethasone prolactin levels in 104 depressed and 42 normal subjects. Serum cortisol levels were also determined in depressed patients before and after dexamethasone administration. We found a significant suppressive effect of dexamethasone on prolactin levels. There were no significant differences either in pre- or postdexamethasone prolactin, or in actual dexamethasone-induced decrements in prolactin between normal controls, melancholics, simple major or minor depressed subjects. We have not found any significant relationships between cortisol and prolactin, either under baseline or postdexamethasone conditions.     

Growth hormone, cortisol and prolactin responses to physical exercise: higher prolactin response in depressed patients

This study was designed to compare growth hormone, cortisol and prolactin responses to physical exercise in depressed patients and healthy comparison subjects. Patients fulfilled the DSM-IV diagnostic criteria for current major depressive disorder; subjective depressive symptoms were rated with Montgomery-Asberg Depression Rating Scale (MADRS) immediately before the experiment. Growth hormone, cortisol and prolactin were measured before and immediately after physiologically stressful bicycle cardiopulmonary exercise test. After exercise, there were three additional hormone measurements, with 30-min intervals. No significant difference was found in baseline growth hormone, cortisol or prolactin levels between patients and the control group. Plasma growth hormone and cortisol levels increased significantly during physical exercise in both patients and controls and returned to baseline in 90 min. There was no significant difference in growth hormone or cortisol responses to physical exercise between the two groups. However, prolactin levels increased only in the depressed patients group during the exercise. We hypothesize that acute exercise may have a stronger effect on serotonin (5-HT) release in depressed patients, which is reflected in increased plasma prolactin concentration.     

Thyroid axis activity and serotonin function in major depressive episode.

Recent studies in depression have reported alterations in both hypothalamic-pituitary-thyroid (HPT) axis activity and serotonin (5-HT) function; however, the functional relationships between the two systems have not been well defined in patients with major depressive episode. Thyrotropin (TSH) response to 0800 and 2300 h protirelin (TRH) challenges, and adrenocorticotropic hormone (ACTH), cortisol, and prolactin (PRL) responses to D-fenfluramine (D-FEN), a specific 5-HT releasing/uptake-inhibiting agent, were examined in 60 drug-free DSM-IV major depressed inpatients and 20 hospitalized controls. Compared with controls, patients showed lower basal serum 2300 h TSH, 2300 h maximum increment in serum TSH above baseline (delta TSH) and difference between 2300 h delta TSH and 0800 h delta TSH (delta delta TSH) levels. The hormonal responses to D-FEN (i.e. delta ACTH, delta cortisol and delta PRL) were interrelated. No significant difference in basal and post-D-FEN ACTH, cortisol or PRL values were found between controls and patients. A negative relationship between hormonal responses to D-FEN and 2300 h delta TSH and delta delta TSH values was observed in the depressed group. When patients were classified on the basis of their delta TSH test status, patients with reduced delta delta TSH values (i.e. with HPT axis abnormality) had hormonal D-FEN responses comparable to those of controls. Patients with normal delta delta TSH values (i.e. without HPT axis abnormality) showed lower ACTH, cortisol and PRL responses to D-FEN than controls and patients with abnormal delta delta TSH values. These results suggest that: (1) pathophysiological mechanisms other than 5-HT dysregulation may be involved in TSH blunting in major depressed patients; (2) 5-HT function is reduced in some depressed patients, especially those without HPT axis abnormality; and (3) HPT dysregulation may be regarded as a compensatory mechanism for diminished central 5-HT activity.     

Platelet serotonin and plasma prolactin and cortisol in healthy, depressed and schizophrenic women

Serotonin (5-hydroxytryptamine, 5-HT) is involved in the regulation of hypothalamic-pituitary-adrenal axis (HPA) activity and prolactin (PRL) secretion. The present study examined the relationship between platelet 5-HT and plasma cortisol and PRL concentrations in 20 schizophrenic, 25 depressed, and 25 healthy women. At the time of blood sampling, the schizophrenic and depressed patients had been drug-free for at least 7 days. Platelet 5-HT, plasma cortisol and PRL concentrations were determined by spectrofluorimetric, radioimmunoassay and immunoradiometric methods, respectively. Platelet 5-HT concentration was significantly higher in schizophrenic patients than in depressed patients or in healthy controls, while it was significantly lower in depressed patients than in healthy controls or in schizophrenic patients. Plasma cortisol levels were significantly increased both in schizophrenic and in depressed patients compared with values in healthy controls. Values of plasma PRL were similar across groups. A significant correlation was found between platelet 5-HT and plasma cortisol, and platelet 5-HT and plasma PRL concentrations in healthy controls, but not in schizophrenic or depressed patients. There was no significant relationship between plasma PRL and cortisol levels in any of the groups. Our data, although obtained on peripheral biochemical markers, indicate that depression and schizophrenia are characterized by disturbed 5-HT transmission and dysregulated HPA axis activity.     

Prolactin responses in dexamethasone suppression test in patients with anorexia nervosa

In anorexia nervosa (AN), abnormalities are present in the hypothalamic-pituitary-adrenal axis, but the prolactin (PRL) response to dexamethasone suppression test (DST) has not yet been studied. In order to study the interrelationships between the various endocrine abnormalities, we investigated the responses of PRL and cortisol to DST (1 mg of dexamethasone at 2300) in AN patients. The subjects were 12 female inpatients with AN and 8 age- and sex-matched healthy controls. The percentage suppression and absolute change in PRL levels before and after dexamethasone administration were significantly different in the 2 groups. In the control group PRL levels suppressed to 36.5 +/- 3.7% of basal, while AN levels declined to 79.4 +/- 8.9% of basal. When the percentage suppression of PRL was compared between patients with and without cortisol suppression, the mean PRL level was 68.9 +/- 7.8% of the basal level for the cortisol-suppressed patients and 100.4 +/- 19.1% for the nonsuppressed patients. Hence in both groups, the percentage PRL suppression was significantly reduced compared with the control group, and indeed nonexistent in cortisol-nonsuppressed patients. The finding that there was less PRL suppression in the cortisol-suppressed patients than in the controls suggests that, in AN, there may be an abnormality in PRL secretion not related to the hypothalamic-pituitary-adrenal axis. Further work is needed to distinguish between the PRL response to stress and potential hypothalamic abnormality.     

Plasma levels of beta-endorphin, cortisol, prolactin and growth hormone in depressed patients

Basal serum cortisol, growth hormone, prolactin and immunoreactive (IR) plasma beta-endorphin levels were measured in 31 depressed patients (14 endogenous, 17 nonendogenous) undergoing the dexamethasone suppression test. The endogenously depressed patients had significantly higher (22.55 +/- 1.34 micrograms/dl) predexamethasone cortisol levels than the nonendogenous patients (16.34 +/- 1.93 micrograms/dl). The mean serum prolactin and growth hormone values of these two groups were not significantly different, while plasma IR-beta-endorphin levels of the endogenous group (40.11 +/- 3.57 pg/ml) were significantly lower than those of the nonendogenous group (120.33 +/- 27.98 pg/ml). Neither group showed a significant correlation between plasma IR-beta-endorphin and serum cortisol values. These results indicate that measurement of predexamethasone serum cortisol values and plasma IR-beta-endorphin could be valuable laboratory tests in the diagnosis of depression.     

Neuroendocrinal study of depression in male epileptic patients

Endocrine changes are reported in both epilepsy and depression. The interrelationships between mood, epilepsy, and endocrine changes are not well characterized. The authors included 40 epileptic patients (20 depressed, 20 nondepressed) and 20 healthy subjects. All patients had an electroencephalogram, and were given the Hamilton Rating Scale for Depression. All subjects were tested for serum levels of cortisol, prolactin, testosterone, and thyroid hormones. Patients were medication-free. Patients had elevated prolactin and cortisol and reduced serum testosterone relative to control subjects. Depressed patients had higher cortisol levels than nondepressed. Data suggest that the effects of epilepsy and depression on cortisol, but not other hormones, may be additive.     

强迫症患者血小板5-羟色胺、血浆催乳素及地塞米松抑制试验的研究

目的　从神经递质与神经内分泌角度探讨强迫症的生化病理机制。方法　采用高效液相色谱法及放射免疫测定法 ,分别测定 2 9例强迫症患者和 2 8名正常对照者血小板 5 羟色胺 (5 HT)含量及血浆催乳素 (PRL)含量 ,并进行地塞米松抑制试验 (DST)。结果　强迫症组血小板 5 HT水平[(0 8± 1 0 )nmol/10 9个血小板 ]低于正常对照组 [(1 4± 1 2 )nmol/10 9个血小板 ],差异有显著性 (P <0 0 5 ) ;而血浆PRL水平 [(337± 192 )nmol/L]与对照组 [(2 87± 116 )nmol/L]相比 ,差异无显著性 (P >0 0 5 ) ;强迫症组于晨 8时的血浆基础皮质醇含量 [(375± 15 2 )nmol/L]高于正常对照组 [(2 6 2± 138)nmol/L],差异有非常显著性 (P <0 0 1) ,其DST阳性率为 2 4 %～ 17% ,与正常对照组 (14 %～ 11% )相比 ,差异无显著性 (P >0 0 5 )。结论　强迫症患者存在 5 HT能低下和神经内分泌功能的紊乱 ,强迫症的 5 HT能假说能解释其某些内分泌功能紊乱。     

Characteristic changes in psychiatric symptoms, cortisol and melatonin but not prolactin in primary hyperparathyroidism

Psychiatric symptoms in primary hyperparathyroidism (PHPT) are usually characterized as depressive. In this study 13 patients with PHPT and six control patients with atoxic nodular goiter underwent psychiatric ratings with the comprehensive psychopathological rating scale (CPRS) the day before surgery. The 21 items in this scale were grouped into clusters. The ratings were repeated after successful removal of a parathyroid adenoma. Diurnal serum concentrations of cortisol, melatonin and prolactin were studied pre- and postoperatively in eight of the patients. Patients with PHPT had significantly higher CPRS total scores, 8.5 +/- 1.3, compared with goiter controls, 1.9 +/- 0.8, and showed a significant improvement of psychiatric symptoms after excision of the parathyroid adenoma, to 3.3 +/- 0.9. The preoperative diurnal and peak levels of cortisol and melatonin were higher (P less than 0.05) than after surgery. Serum melatonin fell to levels lower than those in healthy controls. Correlations were found between some clusters or items and cortisol or melatonin. Serum prolactin levels were normal and unaltered by parathyroid surgery. It is concluded that patients with PHPT show well defined psychiatric symptoms many of which are correlated to alterations in serum cortisol and melatonin accompanying PHPT. The improvement of symptoms seen after successful surgery further suggests that PHPT is associated with a specific psychiatric disorder similar to but distinguishable from major depressive disorder.