Dopamine infusion into the third ventricle increases gene expression of hypothalamic vasoactive intestinal peptide and pituitary prolactin and luteinizing hormone beta subunit in the turkey

Turkey prolactin (PRL) secretion is controlled by vasoactive intestinal peptide (VIP) neurons residing in the infundibular nuclear complex (INF) of the hypothalamus. The VIPergic activity is modulated by dopamine (DA) via stimulatory D(1) DA receptors. DA (10 nmol/min for 40 min) was infused into the third ventricle of laying turkey hens to study its effect on circulating PRL, hypothalamic VIP and pituitary PRL and LHbeta subunit mRNA levels. Plasma PRL was significantly elevated after 20 min of DA infusion and remained elevated 30 min after cessation of infusion. Hypothalamic VIP mRNA content was significantly greater in the INF of DA-infused birds than it was in the INF of vehicle-infused control birds. No increase in VIP mRNA due to DA infusion was noted in the preoptic area. Pituitary PRL and LHbeta subunit mRNAs were increased in DA-infused hens as compared to vehicle-infused controls but the rate of increase was more in PRL than LHbeta subunit. This study demonstrates that exogenous DA activates hypothalamic VIP gene expression and this increased expression is limited exclusively to the avian INF. The increased VIP mRNA in the INF is correlated with increased levels of circulating PRL and PRL and LHbeta mRNAs in the anterior pituitary.     

Immunomodulatory Effects of Sex Hormones: Requirements for Pregnancy and Relevance in Melanoma

Similarities between the pathologic progression of cancer and the physiologic process of placentation (eg, proliferation, invasion, and local/systemic tolerance) have been recognized for many years. Sex hormones such as human chorionic gonadotropin, estrogens, progesterone, and others contribute to induction of immunologic tolerance at the beginning of gestation. Sex hormones have been shown to play contributory roles in the growth of cancers such as breast cancer, prostrate cancer, endometrial cancer, and ovarian cancer, but their involvement as putative mediators of the immunologic escape of cancer is still being elucidated. Herein, we compare the emerging mechanism by which sex hormones modulate systemic immunity in pregnancy and their potentially similar role in cancer. To do this, we conducted a PubMed search using combinations of the following keywords: “immune regulation,” “sex hormones,” “pregnancy,” “melanoma,” and “cancer.” We did not limit our search to specific publication dates. Mimicking the maternal immune response to pregnancy, especially in late gestation, might aid in design of better therapies to reconstitute endogenous antitumor immunity and improve survival.     

蛛网膜下腔出血患者脑脊液垂体激素含量的动态变化

目的研究蛛网膜下腔出血(SAH)患者脑脊液(CSF)促肾上腺皮质激素(ACTH)、促甲状腺激素(TSH)、卵泡刺激素(FSH)、黄体生成素(LH)、泌乳素(PRL)、生长激素(GH)含量的动态变化规律。方法对35例SAH患者发病后1～3d、7～9d、13～15d脑脊液中的ACTH、TSH、FSM、LH、PRL、GH含量进行动态观察，用TCD检测大脑中动脉血流速度(VMCA)。结果SAH患者脑脊液ACTH、TSH、FSH、LH、PRL、GH含量在发病后1～3d、7～9d明显高于对照组，尤以发病后7～9d变化最明显；脑血管痉挛(CVS)组和非CVS组也有明显差异。结论SAH患者脑脊液ACTH、TSH、FSH、LH、GH、PRL含量与病情演变、CVS程度有关，并可判断预后。     

泌乳素瘤动态功能诊断试验的临床评价

目的：评价泌乳素（ＰＲＬ）瘤动态功能诊断试验的临床意义。方法：总结了３８例垂体ＰＲＬ瘤和３７例ＮＰＲＬ瘤的高ＰＲＬ血症患者血清ＰＲＬ基值及用ＴＲＨ、ＭＣＰ和ＬＤ、Ｐａｒｌｏｄｅｌ作ＰＲＬ兴奋及抑制试验结果。计算了各种单项试验的敏感度、特异度、预测值及准确度等指标。结果与结论：ＭＣＰ试验、ＴＲＨ、ＭＣＰ平行及系列试验有统计学意义。提示这三种试验对ＰＲＬ瘤的诊断与ＮＰＲＬ瘤引起的高ＰＲＬ血症进行鉴别具有一定的临床意义     

Possible mechanism of prolactin unresponsiveness to repeated sulpiride administration in man

Summary The mechanisms of prolactin (PRL) unresponsiveness to repeated sulpiride (SUL) injections were investigated in 7 normal males. The experimental protocol consisted of two phases, separated by a 5 day interval. In both phases the administration of 1 mg/kg i. m. of SUL was followed 24 hours later, by the administration of the same dose of SUL together with either placebo (PL, 2 ml saline i. v.) or TRH (200 mcg i. v.). A control TRH test (200 mcg i. v.) was also performed. PRL showed a significant increase after the administration of SUL alone in both phases. Twenty-four hours later plasma PRL was still higher than the basal level and it was not significantly modified by administration of SUL+PL, or by SUL+TRH. The data seem to show that the lack of responsiveness of PRL to repeated administration of SUL is not due to refractoriness of dopaminergic receptors but probably to exhaustion of the hypophyseal PRL pool.     

Characterization of adenohypophysial polypeptides by two-dimensional gel electrophoresis: II. Sulfated and glycosylated polypeptides

Adenohypophysial sulfated and glycosylated polypeptides were studied by high-resolution two-dimensional polyacrylamide-gel electrophoresis followed by fluorography. The preparations analyzed were the following: (a) homogenates from cow and rat anterior pituitary slices labeled in vitro either with [³⁵S]sulfate or d-[6-³H]glucosamine; (b) materials released from bovine adenohypophysis slices pulse labeled with [³⁵S] sulfate; and (c) purified fractions of bovine prolactin granules stripped by detergent treatment of their limiting membrane. A heterogeneous family of sulfated components, almost all glycosylated, differing in their peptide moieties as well as in their isoelectric points, was revealed in the glandular tissue. The major of these components (apparent M_r ~ 70 000; pI ~ 4.8), which was also highly labeled by l-[³H]-leucine (Zanini, A., and Rosa, P. (1981) Mol. Cell. Endocrinol. 24, ???-???), might be a secretory protein because it accumulates in the medium during chase incubation of bovine pituitary slices in vitro. This sulfated component, which was more concentrated in the bovine than in the rat gland, was present in purified bovine prolactin granules stripped of their limiting membrane. However, the available evidence suggests that this might not be the only subcellular location of the sulfated polypeptide in the pituitary tissue.     

溢乳的诊断与治疗

溢乳的定义是非哺乳期乳汁分泌。妇女在非妊娠、非哺乳时泌乳素水平高于20μg/L视为异常。溢乳的病因有某些药物、刺激乳头乳房、甲状腺功能减退、肾脏疾病、丘脑下部功能失调、Forbes-Albright综合征等。泌乳素水平正常,无原因可查时称为“特发性溢乳”。治疗根据溢乳的病因而不同。溴隐亭经口服或阴道放置是治疗垂体微腺瘤或无垂体微腺瘤的高泌乳素血症和溢乳的最新、最有效的首选药物。     

Plasma prolactin and severe premenstrual tension

It has been suggested that elevated luteal phase prolactin (PRL) levels may have an important role in causing some of the symptoms of the premenstrual tension syndrome (PMTS). Thirty-seven women suffering from severe premenstrual dysphoria were selected for this study. Single morning and afternoon serum PRL evaluations were performed during the follicular (day 9) and late luteal (day 26) phases of the menstrual cycle. PRL was measured by an established double antibody radioimmunoassay technique. All mean PRL values were within the normal range. Only afternoon mean PRL levels showed a tendency for a premenstrual increase. The significance of this statistical finding is unclear, since one-third of the subjects showed a decrease in premenstrual PRL levels. Twenty-four hour PRL secretory profiles recorded on days 9 and 26 in two women with extremely severe PMTS and in two asymptomatic matched control subjects also failed to show a significant correlation between PRL levels and PMTS. Thirty subjects participated in a treatment trial using bromocriptine. A marked rebound hyperprolactinemia was observed in a subgroup of women nine days after cessation of bromocriptine. This was associated with no detectable effect on mood, behavior, or menstrual regularity. Thus, our data fail to show any specific relationship between PRL and PMTS.     

Hormone Profiles at High Altitude in Man

Altitude induced alterations in circulatory levels of PRL, LH, FSH and testosterone were studied in seven eugonadal men at sea level (SL), during their stay at high altitude (HA, 3500 m) and a week after return to SL. The mean plasma PRL level at SL was 5.83 +/- 1.7 SE ng/ml. On day one and seven of arrival at HA, the PRL values of 7.81 +/- 1.81 and 9.21 +/- 1.64 ng/ml respectively were not significantly different (p greater than 0.05) than the initial SL values. However, on day 18 of stay at HA, PRL levels were significantly increased (p less than 0.01) to 17.68 +/- 1.82 ng/ml and returned to initial SL values within seven days of return to SL. A significant decrease (p less than 0.01) in LH and testosterone was observed on seventh day of stay at HA and the decreased levels were maintained till day 18 of observations. Plasma testosterone returned to the initial SL values within a week of return to SL, whereas LH levels remained significantly lower (p less than 0.01). The FSH levels did not show any significant change during their stay at HA or after return to SL. These observations suggest that exposure to altitude is associated with hyperprolactenemia and an impaired pituitary gonadal function. The decreased levels of LH and testosterone at HA could either be due to hypoxic stress per se or secondary to altitude induced hyperprolactenemia.     

Hormonal changes induced by a partial opiate antagonist,nalorphine. Evaluation of PRL,GH, TSH,LH, FSH and cortisol secretion

Summary The effects of nalorphine 5 mg i. m., a partial opiate antagonist, on circulating levels of PRL, GH, TSH, LH, FSH and cortisol were studied in six healthy men. Nalorphine produced a prompt and sharp increase in serum PRL and a small, delayed rise in serum GH. Serum LH and cortisol decreased after drug administration and no change in serum FSH and TSH was observed. These findings are discussed and a possible site of action of nalorphine is suggested.