Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Skin allograft rejection was noticeably delayed in rats following hypophysectomy. Daily injections of hypophyseal growth hormone restored the normal reaction. Additional thymectomy had no influence on the rejection of hypophysectomized rats. In these animals growth hormone by itself had no significant influence on the graft rejection. It only restored a normal reaction when given together with thymic hormone. Corticotropin injections accelerated the allograft rejection. On this action of corticotropin thymic hormone has shown a significant inhibitory influence. The thymus was thus proved to be a synergist to growth hormone and an antagonist to corticotropin. Previous observations made with usual endocrinological test- are thus confirmed with an immunological test.
 ...
PMID:Influence of the thymus-corticothropin-growth hormone interaction on the rejection of skin allografts in the rat. 16 68

In an attempt to determine the role of protein (histone) kinases as mediators of corticotropin-induced corticosterone formation, the ability of homogenates, prepared from adrenals treated with various doses of corticotropin to catalyse the phosphorylation of calf thymus histones was measured. Although corticotropin promoted an increase in histone kinase activity, much more of the hormone was required to induce this response than to stimulate steroidogenesis maximally. In addition, a derivative, nitrophenylsulphenyl-corticotropin, which inhibits the stimulatory effect of corticotropin on cyclic AMP accumulation, stimulated corticosterone synthesis without altering histone kinase activity. Very high doses of nitrophenylsulphenyl-corticotropin were capable of stimulating histone kinase activity. In contrast, when dibutyryl cyclic AMP was used to stimulate steroidogenesis under the same conditions, any dose of the nucleotide which increased adrenal corticosteroid content also increased histone kinase activity. Assuming that histones serve as useful substrates for measurement of total adrenal protein kinase activity, the role of protein kinases as mediators of steroidogenesis is not supported by these studies.
 ...
PMID:Role of histone kinases as mediators of corticotropin-induced steroidogenesis. 18 14

Lutropin and human choriogonadotropin stimulated the endogenous chromatin-associated polymerase activity in purified chromatin prepared from nuclei of bovine corpus luteum. Chromatin was incubated in two different buffer systems: one that mainly supports the activity of polymerase I, another that supports the activity of polymerase II and is largely alpha-amanitin sensitive. The hormones lutropin and chorigonadotropin stimulated an increase in the rate of incorporation of [14C]ATP or [14C]UTP into RNA in both buffer systems. Follitropin, prolactin and beta-corticotropin had no stimulatory effect. Neither the alpha nor beta subunit of lutropin stimulated RNA synthesis. When premixed, the subunits rapidly formed the active molecule. A maximum response to RNA synthesis was achieved by a 10(-9) M concentration of human choriogonadotropin. Considerable activity was obtained at 10(-11) M human choriogonadotropin. There was no lutropin stimulation to RNA synthesis using calf thymus DNA and Escherichia coli RNA polymerase.
 ...
PMID:Lutropin stimulation of RNA synthesis in corpus luteum chromatin. 32 86

The bibliography concerning the interaction of the thymus with other endocrines is summarized. The thymus, the lymph nodes and the spleen of Sprague-Dawley rats were extracted with the method of Bezssonoff and Comsa and the extracts fractionated with the method of Bernardi and Comsa. The animals were (1) normal, (2) adrenalectomized, (3) adrenalectomized and substituted with one or several corticosteroids, (4) adrenalectomized and thymectomized, (5) thyroidectomized, (6) thyroidectomized and substituted with thyroxine, (7 and 8) castrated (males or females), (9 and 10) castrates substituted with sexual hormones, (11) castrated and adrenalectomized, (12) castrated and thyroidectomized, (13) castrated, adrenalectomized and thyroidectomized, (14) hypophysectomized, and (15) hypophysectomized and substituted with one hypophyseal hormone. In the Bernardi-Comsa preparations hormone was determined by UV-spectrophotometry. Adrenalectomy resulted in a significant decrease of the hormone content of the thymus (which was still more attenuated by cortisol) and its increase in the lymph nodes and the spleen. Corticosterone and desoxycorticosterone increased the hormone content in all three tissues, whilst aldosterone increased it in the thymus and decreased it in the lymph nodes and the spleen. Thyroidectomy resulted in a significant decrease of the hormone in the thymus and its quasi-disappearance from the lymph nodes and the spleen. This was prevented by thyroxine therapy. Castration resulted in an increase of the hormone content in all three tissues. This was prevented by sexual hormone therapy. Hypophysectomy resulted in decrease of the hormone content in all three tissues. This was prevented by injections with growth hormone, corticotropin and thyrotrophin. These results were compared with those of histological examinations of thymus, lymph nodes and spleen in the corresponding experimental groups. The consistency was found satisfactory.
 ...
PMID:Hormonal influences on the secretion of the thymus. 57 3

The thymosins are a family of hormone-like products of epithelial cells of the thymus which are important in maintenance and function of the immune system. Thymosin fraction 5, a partially purified extract of calf thymus, can influence pituitary hormone release. We have studied the effects of thymosin alpha 1 (T alpha 1), the first peptide isolated from thymosin fraction 5, on thyrotropin (TSH), adrenocorticotropin (ACTH), prolactin (Prl) and growth hormone (GH) release. To evaluate its effect in vivo we injected the peptide into the third ventricle of conscious male rats and measured the concentration of the pituitary hormones in plasma at different times after the injection. Following third-ventricular injection of T alpha 1, there was a significant decrease in plasma TSH and ACTH concentrations in comparison with values of control groups injected with diluent. The decrease in plasma TSH was of longer duration and was obtained with a lower dose of T alpha 1 than that of ACTH. Also, a significant decrease in plasma Prl was observed, with the same dose as for TSH. On the other hand, there were no significant changes in plasma GH. To examine if there is any direct effect of T alpha 1 at the pituitary level, we incubated hemipituitaries from male rats in vitro with different concentrations of the peptide. In this system T alpha 1 evoked a dose-dependent release of TSH and ACTH, while there was no effect on the release of Prl and GH.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of thymosin alpha-1 on pituitary hormone release. 131 3

Three patients with Cushing syndrome due to ectopic production of corticotropin underwent total thymectomy on the basis of elevated concentrations of corticotropin in selective samples from thymic veins but in the absence of a radiographically detectible thymic mass. In one patient, radiologic examination demonstrated hyperplasia of neuroendocrine cells staining positively for corticotropin throughout the thymus but no discrete mass. This patient had complete remission after total thymectomy. The other two patients had no evidence of an intrathymic source of corticotropin, and both had persistent Cushing syndrome. Elevated levels of corticotropin in thymic vein samples may reflect corticotropin production by pulmonary bronchial carcinoid tumors, mediastinal metastases, thymic carcinoids, or diffuse hyperplasia of intrathymic neuroendocrine elements. In the absence of a demonstrable intrathymic mass, corticotropin gradients in thymic veins do not reliably indicate a thymic source of corticotropin and should not necessarily be used as a basis for exploratory thoracotomy or blind thymectomy.
 ...
PMID:Corticotropin-secreting carcinoid tumors of the thymus: diagnostic unreliability of thymic venous sampling. 131 78

Male Wistar rats living in colonies of 4 males plus 4 females were compared to noncolony males, cohabitating with a female. Irreversible dominance relationships developed between one dominant male (D) and three subordinates (S). Dominants developed high basal testosterone levels and large preputial glands. Subordinates had reduced preputial glands despite normal testicle weights and normal basal testosterone levels. Basal corticosterone was elevated in both ranks, in S more so than in D, while in acute encounters both ranks showed a similar increase in the corticosterone-to-ACTH ratio. They also underwent a similar reduction in thymus weight, while an increase in adrenal weight was more pronounced in D. In D-S-I encounters, during which D simultaneously attacked S and an intruder (I) for 20 minutes, both defenders showed a 3-4 fold increase in plasma prolactin, while in the offensive dominant the level remained low. Similar, but weaker hormonal contrasts between offence and defence were found for beta-endorphin, ACTH, and corticosterone, while alpha-MSH and testosterone did not discriminate. In our view, the marked hyporesponsiveness of prolactin to acute offence may be associated with a specific offensive setting of dopaminergic inhibitory and beta-adrenergic stimulatory influences.
 ...
PMID:Hormonal reactions to fighting in rat colonies: prolactin rises during defence, not during offence. 131 90

The responses of the hypothalamic-pituitary-adrenal axis during chronic stress are characterized by normal or slightly elevated plasma ACTH, increased hypothalamic corticotropin-releasing hormone (CRH) and vasopressin secretion, decreased pituitary CRH receptors and hypersensitivity of the ACTH and glucocorticoid responses to a novel stress. To determine the role of CRH and vasopressin in the pituitary hyperresponsiveness to a superimposed stress, pituitary CRH receptors and plasma ACTH responses were measured in rats receiving minipump infusions of CRH or a combination of CRH and vasopressin (VP), 50 ng/min of each for 50 h. Rats were killed by decapitation with or without exposure to ether vapor for 5 min or immobilization for 15 or 30 min, and blood was collected for ACTH and corticosterone determinations. The pituitary CRH receptor concentration measured by binding 125I-Tyr-oCRH, was reduced by 45 and 80% in CRH- and CRH-plus-VP-infused rats, respectively, with no changes in receptor affinity. Acute stress by ether exposure or immobilization had no effect on pituitary CRH receptors. Adrenal weight was significantly increased, and thymus weight decreased in CRH-infused animals, indicating activation of the pituitary adrenal axis. However, in contrast to the responses following chronic stress, the increases in plasma ACTH in response to an injection of 10 micrograms/kg CRH or acute stress were significantly lower in CRH- and CRH-plus-VP-infused rats. Furthermore the content and release of ACTH from quartered pituitaries were also decreased in chronically treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Desensitization of the hypothalamic-pituitary-adrenal axis following prolonged administration of corticotropin-releasing hormone or vasopressin. 133 16

Thymosin alpha 1 (T alpha 1) is a well-characterized immunopotentiating polypeptide originally isolated from calf thymus. We have recently shown in vivo, probable hypothalamic effects of T alpha 1 to decrease the release of the pituitary hormones, TSH, PRL and ACTH from the pituitary gland. Therefore, in the present study we evaluated the effect of the peptide on the release of hypothalamic regulatory hormones: thyrotropin-releasing hormone (TRH) and corticotropin-releasing hormone (CRH), as well as somatostatin (SRIH), from medial basal hypothalamic (MBH) fragments incubated in vitro. After a preliminary time-course study indicated that a 30-min incubation period was optimal, it was used for all the other experiments. At the end of the incubation the tissue was still able to respond to a depolarizing K+ concentration for 15 min by a 4-fold increase of TRH concentration compared to control basal release during the preceding 30 min. T alpha 1 was shown to inhibit the release of TRH and CRH from MBH fragments incubated in vitro with a minimal effective dose (MED) of 10(-11) M. SRIH and CRH release was also inhibited but the MED for these peptides was 10(-9) M. The relative responsiveness to the action of T alpha 1 was TRH greater than CRH, which was greater than SRIH. This correlated with our previous in vivo results for pituitary hormone release, except in the case of SRIH since we previously did not detect any significant effect of the peptide on growth hormone release. Finally, we evaluated the possible involvement of other neurotransmitters in the effect of T alpha 1 on TRH release.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effect of thymosin alpha 1 on hypothalamic hormone release. 136 97

We evaluated the presence of anterior pituitary hormones; follicle-stimulating hormone (FSH) and its beta-subunit (beta-FSH), luteinizing hormone (LH) and its beta-subunit (beta-LH), beta-subunit of thyroid-stimulating hormone (beta-TSH), adrenocorticotropic hormone (ACTH), growth hormone (GH), and prolactin (PRL); the placental hormone human chorionic gonadotropin (hCG); and somatostatin, in paraffin and frozen sections of the human thymus. Epithelial cells in the medulla were immunoreactive for most of these hormones, in varying density and intensity of labeling. The cells labeled varied from epithelial cells surrounding Hassall's corpuscles toward solitary cells or small epithelial aggregates in the medulla. FSH immunoreactivity did occur predominantly in epithelial cells of the cortex, in apparent contrast to the predominant medullary location of cells immunolabeled for beta-FSH. The epithelial nature of FSH-immunoreactive cells was confirmed by two-color immunohistochemistry with anti-keratin antibody. In addition to FSH, some epithelial cells in subcapsule and cortex were labeled by antibodies to beta-FSH, beta-LH, beta-TSH, ACTH, GH, and PRL. Some macrophage-like cells surrounded by a rosette of lymphocytes were immunoreactive for FSH and GH. Some interdigitating reticulum-like cells were labeled by anti-beta-LH. Immunolabeling of lymphocytes was found for hCG, especially lymphocytes in the medulla. Two-color immunohistochemistry with anti-CD3 revealed a strong CD3 expression on hCG-immunoreactive cells, whereas CD3-negative cells were hCG-negative. T cells immunolabeled for hCG were also found in peripheral lymphoid organs.
 ...
PMID:The neural and neuro-endocrine component of the human thymus. II. Hormone immunoreactivity. 139


1 2 3 4 5 6 7 8 9 10 Next >>