Serum prolactin levels and maintenance of progeny by prenatally-stressed female offspring.

Prenatal stress significantly reduced the number of progeny born to 47% of the female offspring and significantly increased the incidence of low birthweight young. None of these litters survived by the tenth postpartum day when serum prolactin levels were significantly reduced. Upon autopsy, these females had twice as many uterine implantation sites than the number of fetuses they bore, suggesting that a) the reduced postpartum serum prolactin most likely was the cause rather than the effect of the neonatal mortality and b) major hormonal deficiencies (possibly gonadotropic-related) were present even before giving birth.     

Influence of somatostatin on serum prolactin concentrations of cows during rest and milking

Summary Administration of somatostatin (SRIF) to lactating cows significantly increased basal, premilking serum concentrations of prolactin (PRL), and potentiated PRL release in response to milking and significantly reduced resting concentrations of growth hormone (GH).The author wishes to thank Ayerst Laboratories of Canada for donating the somatostatin for these studies.     

Influence of somatostatin on serum prolactin concentrations of cows during rest and milking

Administration of somatostatin (SRIF) to lactating cows significantly increased basal, premilking serum concentrations of prolactin (PRL), and potentiated PRL release in response to milking and significantly reduced resting concentrations of growth hormone (GH).     

Effects of thyroidectomy and thyroxine replacement on the responsiveness of the anterior pituitaries from male rats to thyrotropin-releasing hormone in vitro

Summary Thyroidectomy decreased prolactin concentrations in the anterior pituitary (AP) and serum of the male rat. The amount of basal and thyrotropin-releasing hormone (TRH)-stimulated release of prolactin by AP in vitro was lower in thyroidectomized (Tx) rats than in sham Tx rats. These results suggest that the inhibitory effects of thyroidectomy on pituitary and serum prolactin in male rats are mediated in part by the reduction of the production and spontaneous release of prolactin and the responsiveness of prolactin to TRH.     

Studies on the thyroid in transgenic mice expressing the genes for human and bovine growth hormone

The thyroid glands of transgenic mice (TM) expressing the genes for human (h) and bovine (b) growth hormone (GH) were studied. The percentages of larger follicles in hGH TM of either sex were significantly greater than in the corresponding normal littermates, and follicles ranging up to 350 microns in diameter were present in male hGH TM. In contrast, thyroid follicles were only slightly enlarged in male bGH TM, and were unchanged in female bGH TM. The serum concentrations of T4 were significantly decreased in male bGH TM and not altered in the other groups. Serum concentrations of T3 were slightly, but significantly increased in female hGH TM and female bGH TM, but were unaffected in male TM of either type. Since the principal difference between these foreign GHs in rodents is the additional lactogenic activity of human GH, these results may indicate that the effects of prolactin can influence the development of the thyroid.     

Effect of apomorphine hydrochloride administration on serum concentrations of prolactin,and growth hormone in cattle

Summary Administration of apomorphine hydrochloride to cattle significantly depressed serum prolactin (PRL) concentrations and elevated serum growth hormone (GH) concentrations in a dosimetric fashion.     

Proestrous gonadotropin levels in thyroparathyroidectomized female rats

Summary Intact and TPTx animals showed the expected afternoon increase in serum LH, FSH and prolactin levels. But the afternoon increase in serum LH levels in TPTx rats was less than that observed for intact animals (p<0.01). Neither serum prolactin nor FSH levels were altered by TPTx.The excellent technical and secretarial assistance ofS. Hemelt andD. Landman is gratefully acknowledged.     

Regulation of estrogen "receptors" in mammary tumors: action of prolactin in vivo

The effect of prolactin on estradiol receptors was determined in cytosol of estrogen-dependent mammary tumors of Sprague Dawley rats. Tumors were induced with 20 mg dimethylbenzanthracene, rats were ovariectomized, and the rats showing regression in tumor weight were given 1 mg sheep or rat prolactin for 5 days. Receptors were separated by dextran-charcoal and analyzed by sucrose gradient. Prolactin, milk proteins, serum proteins, and 1-alpha-feto-proteins were excluded immunologically. The estradiol receptors resembled uterine receptors in affinity, specificity, sedimentation, and nuclear transfer under estradiol influence. Castration diminished receptor content exponentially 170 f moles to 16 f moles/mg protein within 10 days; prolactin increased the number of receptors to 87 f moles compared with 15 in controls. Affinity, cellular location, and uterine receptor content were unaffected. Sheep and rat prolactin acted similarly. These results justify hypophysectomy as therapy for certain estrogen-dependent breast tumors.     

Vasoactive intestinal polypeptide stimulates prolactin release in vivo in the ring dove (Streptopelia risoria)

Summary I.v. administration of vasoactive intestinal polypeptide (VIP) to ring doves significantly elevated the plasma concentration of prolactin after 10 min in a dose-related manner. The plasma prolactin concentration of nonbreeding doves with low basal levels was increased by a similar amount as in brooding doves whose initially high concentration of plasma prolactin had been reduced by nest deprivation prior to treatment.     

Vasoactive intestinal polypeptide stimulates prolactin release in vivo in the ring dove (Streptopelia risoria)

I.v. administration of vasoactive intestinal polypeptide (VIP) to ring doves significantly elevated the plasma concentration of prolactin after 10 min in a dose-related manner. The plasma prolactin concentration of nonbreeding doves with low basal levels was increased by a similar amount as in brooding doves whose initially high concentration of plasma prolactin had been reduced by nest deprivation prior to treatment.     

Plasma steroid and protein hormone concentrations in patients with benign prostatic hypertrophy and in normal men.

Serum levels of testosterone, FSH, LH and prolactin were measured by RIA in patients with BPH (benign prostatic hypertrophy) and in control men. The testosterone concentrations in the BPH group were significantly lower than that of the control group. Serum concentrations of FSH, LH, prolactin and estradiol, did not differ significantly in the 2 groups.     

Plasma steroid and protein hormone concentrations in patients with benign prostatic hypertrophy and in normal men

Summary Serum levels of testosterone, FSH, LH and prolactin were measured by RIA in patients with BPH (benign prostatic hypertrophy) and in control men. The testosterone concentrations in the BPH group were significantly lower than that of the control group. Serum concentrations of FSH, LH, prolactin and estradiol, did not differ significantly in the 2 groups.     

Studies on the thyroid in transgenic mice expressing the genes for human and bovine growth hormone

Summary The thyroid glands of transgenic mice (TM) expressing the genes for human (h) and bovine (b) growth hormone (GH) were studied. The percentages of larger follicles inhGH TM of either sex were significantly greater than in the corresponding normal littermates, and follicles ranging up to 350 m in diameter were present in malehGH TM. In contrast, thyroid follicles were only slightly enlarged in malebGH TM, and were unchanged in femalebGH TM. The serum concentrations of T4 were significantly decreased in malebGH TM and not altered in the other groups. Serum concentrations of T3 were slightly, but significantly increased in femalehGH TM and femalebGH TM, but were unaffected in male TM of either type. Since the principal difference between these foreign GHs in rodents is the additional lactogenic activity of human GH, these results may indicate that the effects of prolactin can influence the development of the thyroid.     

Lesions in suprachiasmatic nuclei simulate effects of pinealectomy on prolactin release in ovariectomized and sulpiride-treated female rats

Previous studies indicate that the pineal gland alters prolactin secretion, and it was suggested that at least part of the effect of the pineal hormone melatonin on prolactin release may be mediated by the hypothalamic structures. In this study, pinealectomy and lesions of the suprachiasmatic nuclei were found to alter serum levels of prolactin in the same direction, an effect that was counteracted by daily afternoon melatonin administration. Melatonin, but not other pineal indoles, also prevented sulpiride-induced prolactin secretion in pinealectomized or suprachiasmatic nuclei-lesioned and ovariectomized rats, which suggested that the pineal gland can modulate prolactin secretion by acting through a dopamine mechanism independent of hypothalamic suprachiasmatic structures.     

Emblica officinalis reduces serum, aortic and hepatic cholesterol in rabbits

Emblica officinalis reduced serum cholesterol (p less than 0.001), aortic cholesterol (p less than 0.001) and hepatic cholesterol (p less than 0.001) significantly in rabbits. Emblica officinalis did not influence euglobulin clot lysis time, platelet adhesiveness or serum triglyceride levels.     

Reduction of body fat stores by inhibition of prolactin secretion

Reductions of prolactin secretion by bromocriptine treatment for 24 days reduced fat stores (abdominal and epididymal fat depots) in hamsters by 25-49% compared with control animals. However, body weights and food consumption were not affected. These results further substantiate an important role for prolactin in regulation of fat metabolism and indicate that bromocriptine might be used to decrease fat stores.     

Reduction of body fat stores by inhibition of prolactin secretion

Summary Reductions of prolactin secretion by bromocriptine treatment for 24 days reduced fat stores (abdominal and epididymal fat depots) in hamsters by 25–49% compared with control animals. However, body weights and food consumption were not affected. These results further substantiate an important role for prolactin in regulation of fat metabolism and indicate that bromocriptine might be used to decrease fat stores.     

Diltiazem prevents the damage to cultured aortic smooth muscle cells induced by hyperlipidemic serum

Diltiazem, a calcium antagonist, significantly reduced the increased 45Ca uptake and the number of dead cells in cultured aortic smooth muscle cells induced by hyperlipidemic serum.     

连续性血液净化治疗对重症急性胰腺炎患者内皮细胞通透性的影响

目的探讨连续性血液净化治疗对重症急性胰腺炎(severeacutepancreatitis,SAP)患者内皮细胞的作用.方法人脐静脉内皮细胞(HumanUmbilicalVeinEndothelialCells,HUVEC)按实验分组分别用16例健康对照组血清,38例 SAP患者连续性血液净化(ContinuousBloodPurificantion,CBP)治疗前、治疗6h、治疗20h血清体外干预脐静脉内皮细胞5h.transwell小室观察内皮细胞通透性变化,激光共聚焦显微镜观察 F actin应力微丝的表达及分布.结果 SAP患者 CBP治疗前内皮细胞通透性较健康对照组明显增高(P<0.01),CBP治疗6h、治疗20h后通透性均降低(P<0.05),但治疗20h组与治疗6h组相比,差异无显著性(P>0.05).激光共聚焦结果显示,与健康对照组相比,CBP治疗前 SAP患者内皮细胞 F actin应力微丝的数量及密度均明显增加,CBP治疗6h后,F actin应力微丝形成减少,治疗20h后减少更加显著.结论重症急性胰腺炎患者内皮细胞通透性明显增加,CBP治疗可以显著降低 SAP患者内皮细胞通透性,其机制可能与调节 F actin应力微丝形成与分布有关     

Effects of Freund's complete adjuvant on the dirunal rhythms of neuroendocrine processes and ornithine decarboxylase activity in various tissues of male rats

The aim of this study was to investigate the effects of Freund's complete adjuvant (FCA) on the diurnal rhythms of hormonal parameters in serum and ornithine decarboxylase (ODC) activity in various tissues of male rats. On days 1–2 after FCA, increase of ODC activity (used to evaluate the level of activation) was observed in the hypothalamus, pituitary gland, adrenal medulla, adrenal cortex, liver and lymphoid tissues, while the ODC activity in the kidney was reduced. This was accompanied by an increase in serum corticosterone. On days 3–4 after FCA, ODC activity remained elevated in the pituitary gland, liver and lymphoid tissues, while the ODC activity in the testes and panceas was reduced; kidney ODC activity returned to baseline. This was associated with increased serum levels of prolactin (Prl) and luteinizing hormone, but decreased growth hormone, testosterone and insulin. The increase in ODC activity in the thymus, as well as the reduced ODC activity in the testes and kidney, can be obtained with paraffin. Furthermore, bromocryptine microcapsules (CBLA) reduced the FCA-induced increase of ODC activity in the pituitary gland, liver and lymphoid tissues (days 3–4) but did not affect the changes in other tissues. The increase in ODC activity in the pituitary gland, liver and lymphoid tissues is specific for FCA. A role for Prl in the induction of ODC in liver and lymphoid tissues is suggested by the fact that CBLA suppresses this enhancement.