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)

The present report concerns the immunocytochemistry of various peptide hormones and in particular their location in nervous structures. However, since the hormones observed in the neuroadenohypophysis and the digestive tractus have been examined elsewhere, they have been excluded from this study, except when considered outside there precise areas. The immunocytology of the following neuropeptides is presented, especially the particular details related to their demonstration: 1) The hypothalamic hypophysiotropic factor: LH-RF, SRIF, TSH-RF; derivatives from the so-called proopiocortine found by Mains and Eipper (1977), namely beta-LPH, enkephalins, endorphins, alpha-MSH- and ACTH-like antigens; 2) Prolactin and somathormone found outside the pituitary; 3) Gastro-intestinal hormones and their location outside the digestive hormones and their location outside the digestive mucosa, namely VIP, CCK, substance P; 4) Angiotensin II in nervous structures; 5) Neurotensin; 6) Thyrocalcitonin; 7) Relaxin, and the problem of its presence in the adult male genital tract. New data in invertebrate located vertebrate neuropeptides-like antigens in the nervous structures of pro-chordates (Ascidians) insects, crustaceans, annelids. These last findings underline the extensive significance of such hormonal molecules previously considered to be specific for vertebrates.
...
PMID:Immunocytochemistry of polypeptide hormones: a review. 616 60

To investigate the role of non-ACTH pituitary peptides on steroidogenesis, we studied the effects of synthetic beta-lipotropin, beta-melanotropin, and beta-endorphin on aldosterone and corticosterone stimulation using rat adrenal collagenase-dispersed capsular and decapsular cells. beta-lipotropin induced a significant aldosterone stimulation in a dose-dependent fashion (10 nM-1 muM). beta-endorphin, which is the carboxyterminal fragment of beta-lipotropin, did not stimulate aldosterone production at the doses used (3 nM-6 muM). beta-melanotropin, which is the middle fragment of beta-lipotropin, showed comparable effects on aldosterone stimulation. beta-lipotropin and beta-melanotropin did not affect corticosterone production in decapsular cells. Although ACTH(1-24) caused a significant increase in cyclic AMP production in capsular cells in a dose-dependent fashion (1 nM-1 muM), beta-lipotropin and beta-melanotropin did not induce an increase in cyclic AMP production at the doses used (1 nM-1 muM). The beta-melanotropin analogue (glycine[Gly](10)-beta-melanotropin) inhibited aldosterone production induced by beta-lipotropin or beta-melanotropin, but did not inhibit aldosterone production induced by ACTH(1-24) or angiotensin II. Corticotropin-inhibiting peptide (ACTH(7-38)) inhibited not only ACTH(1-24) action but also beta-lipotropin or beta-melanotropin action; however it did not affect angiotensin II-induced aldosterone production. (saralasin [Sar](1); alanine [Ala](8))-Angiotensin II inhibited the actions of beta-lipotropin and beta-melanotropin as well as angiotensin II. These results indicate that (a) beta-lipotropin and beta-melanotropin cause a significant stimulation of aldosterone production in capsular cells, (b) beta-lipotropin and beta-melanotropin have a preferential effect on zona glomerulosa cells, (c) beta-melanotropin contains the active peptide core necessary for aldosterone stimulation, (d) the effects of these peptides on aldosterone production may be independent of cyclic AMP, and (e) the receptors for beta-lipotropin or beta-melanotropin may be different from those for ACTH or angiotensin II.
...
PMID:Effects of beta-lipotropin and beta-lipotropin-derived peptides on aldosterone production in the rat adrenal gland. 626 63

Angiotensin II (ANG II) acts on the brain to elevate blood pressure (BP), stimulate drinking, increase the secretion of vasopressin and corticotropin (ACTH), and inhibit the secretion of renin. The present studies were designed to evaluate the possible physiological significance of these effects. The experiments were performed in conscious dogs with small catheters chronically implanted in both carotid and both vertebral arteries. ANG II was infused into both carotid or both vertebral arteries in doses of 0.1, 0.33, 1.0, and 2.5 ng.kg-1.min-1. Intravertebral ANG II produced dose-related increases in BP that were generally accompanied by increases in heart rate. Intracarotid angiotensin also increased BP but did not change heart rate. Intracarotid ANG II stimulated drinking and, at the highest dose only, increased the secretion of vasopressin, ACTH, and corticosteroids. Intravertebral and intracarotid ANG II suppressed plasma renin activity (PRA). In a parallel series of experiments, the effects of intravenous ANG II, in doses of 2, 5, 10, and 20 ng.kg-1.min-1, were studied. These infusions produced dose-related increases in BP and water intake and suppressed PRA. Only the highest dose of ANG II increased vasopressin or corticosteroid secretion. Analysis of these results in terms of calculated or measured changes in plasma ANG II concentration indicate that the central cardiovascular and dipsogenic actions of angiotensin, as well as the suppression of PRA, can be elicited by concentrations of the peptide that are within the physiological range. On the other hand high, probably supraphysiological, levels of ANG II are required to increase vasopressin or ACTH secretion.
...
PMID:Analysis of the actions of angiotensin on the central nervous system of conscious dogs. 628 22

To assess the function of the final step of the pathway for aldosterone biosynthesis, the responsiveness of plasma 18-hydroxycorticosterone and aldosterone concentrations to angiotensin II infusion was studied in 14 patients with nonazotemic diabetes mellitus as compared with 14 normal controls approximately matched for sex and age. In addition, the responses of both steroids to corticotropin injection were investigated in the diabetic patients. Under basal conditions, plasma aldosterone levels were slightly lower in the patients than in normal controls, while plasma 18-hydroxycorticosterone concentrations were similar in the two study groups. Angiotensin II induced marked and comparable increases in plasma 18-hydroxycorticosterone and aldosterone levels in normal and diabetic subjects. Plasma 18-hydroxycorticosterone and aldosterone levels before and after angiotensin II infusion were significantly interrelated; this correlation was similar in normal subjects (r = 0.61; P less than 0.001) and diabetic patients (r = 0.51; P less than 0.005). Plasma 18-hydroxycorticosterone and aldosterone were significantly increased by corticotropin in the patients. These findings indicate that the terminal step of aldosterone biosynthesis, which involves the production of 18-hydroxycorticosterone and aldosterone, is largely unaltered in patients with nonazotemic diabetes mellitus.
...
PMID:Responsiveness of plasma 18-hydroxycorticosterone and aldosterone to angiotensin II or corticotropin in nonazotemic diabetes mellitus. 629 99

The in vitro secretion of aldosterone and corticosterone by the adrenal glands of fetal (day 30), pregnant and non-pregnant rabbits was examined under basal and stimulated conditions. In general, non-pregnant animals basally secreted less aldosterone than either pregnant or fetal rabbits, whereas basal corticosterone secretion by pregnant animals exceeded that of either fetal or non-pregnant animals. At similar doses of adrenocorticotropin (ACTH), fetal and pregnant adrenal glands produced comparatively more aldosterone than non-pregnant animals, while corticosterone secretion was accelerated to a greater degree in fetal rabbits than in the other groups. Angiotensin II had its greatest effect on the aldosterone secretory rates of fetal and non-pregnant animals without affecting corticosterone secretion in any group. Elevated potassium (K+) enhanced the secretory rates of aldosterone and corticosterone in fetal animals, while increasing only aldosterone secretion in non-pregnant rabbits. Serotonin accelerated aldosterone secretion in all animals, whereas it increased corticosterone secretion only in non-pregnant animals. These results suggest that (1) in fetal rabbits, the secretory rates of both aldosterone and corticosterone are regulated primarily by ACTH and to a much lesser extent by angiotensin II and K+, (2) the corticosterone secretory rates of pregnant and non-pregnant rabbits are controlled mainly by ACTH, and (3) aldosterone secretion by non-pregnant animals is regulated primarily by angiotensin II and secondarily by ACTH and K+, while in pregnant animals ACTH may be the primary regulator of aldosterone secretion as it is in the fetus.
...
PMID:Comparative in vitro responses of fetal, pregnant and non-pregnant rabbits' adrenal glands to steroidogenic agents. 630 96

A number of neuropeptides have been found to affect fluid intake when injected directly into the brain of various vertebrate species. These include: angiotensin II and its peptide precursors; the tachykinins Substance P, eledoisin and physalaemin; the opioid peptides met- and leu-enkephalin and beta-endorphin; bombesin; neurotensin; and vasopressin. Some of these stimulate drinking, some inhibit water intake, and the tachykinins have opposite effects on thirst depending on the species tested. Very little is known about the site or mechamism of action of most of these peptides or if their effects on thirst are physiological. The exception is angiotensin II, a peptide hormone that is synthesized in the blood in response to hypovalaemia or hypotension and is involved in many aspects of the regulation of blood volume and pressure. Angiotensin II injected intravenously or intracranially stimulates drinking in all reptiles, birds and mammals tested. In addition to its role as a hormone, angiotensin II may also function as a neurotransmitter or neuromodulator, since all of the enzymes and precursors necessary for its synthesis have been found in the central nervous system.
...
PMID:Neuropeptides and thirst. 658 33

Angiotensin II (AII) receptors are known to interact with two distinct guanine nucleotide binding proteins, Gq/11 and Gi, in rat adrenal glomerulosa cells to activate phospholipase C and to inhibit adenylate cyclase, respectively. However, in cultured bovine glomerulosa cells AII potentiates rather than inhibits the stimulatory effect of adrenocorticotropin (ACTH) on cAMP levels. This effect of AII was partially mimicked by phorbol 12-myristate 13-acetate (PMA) and was partially inhibited by staurosporine or depletion of protein kinase C but was unaffected by pertussis toxin treatment. No potentiation was detectable in disrupted cells or in membrane preparations. In intact glomerulosa cells, treatment with cyclosporin A or FK506 completely inhibited AII- or PMA-induced potentiation of cAMP production without affecting the response to ACTH. In COS-7 cells transfected with the rat AT1 receptor, AII caused 2-3-fold enhancement of the ACTH-induced cAMP response, an effect that was partially reproduced by PMA. These potentiating actions of AII and PMA were prevented by preincubation with cyclosporin A or FK506, and the latter effect was abolished by rapamycin. These results implicate the Ca2+- and calmodulin-dependent protein phosphatase, calcineurin, in AII-induced enhancement of adenylate cyclase activity in both adrenal glomerulosa and transfected COS-7 cells. The finding that AII enhances ACTH-stimulated production of cAMP by a second messenger-mediated mechanism that involves the participation of calcineurin reveals an additional mode of cross-talk between pathways activated by Ca(2+)-mobilizing and cAMP-generating receptors.
...
PMID:Evidence for participation of calcineurin in potentiation of agonist-stimulated cyclic AMP formation by the calcium-mobilizing hormone, angiotensin II. 792 24

In addition to increasing blood pressure, stimulating aldosterone and vasopressin secretion, and increasing water intake, angiotensin II affects the secretion of anterior pituitary hormones. Some of these effects are direct. There are angiotensin II receptors on lactotropes and corticotropes in rats, and there may be receptors on thyrotropes and other secretory cells. Circulating angiotensin II reaches these receptors, but angiotensin II is almost certainly generated locally by the pituitary renin-angiotensin system as well. There are also indirect effects produced by the effects of brain angiotensin II on the secretion of hypophyseotropic hormones. In the anterior pituitary of the rat, the gonadotropes contain renin, angiotensin II, and some angiotensin-converting enzyme. There is debate about whether these cells also contain small amounts of angiotensinogen, but most of the angiotensinogen is produced by a separate population of cells and appears to pass in a paracrine fashion to the gonadotropes. An analogous situation exists in the brain. Neurons contain angiotensin II and probably renin, but most angiotensin-converting enzyme is located elsewhere and angiotensinogen is primarily if not solely produced by astrocytes. Angiotensin II causes secretion of prolactin and adrenocorticotropic hormone (ACTH) when added to pituitary cells in vitro. Paracrine regulation of prolactin secretion by angiotensin II from the gonadotropes may occur in vitro under certain circumstances, but the effects of peripheral angiotensin II on ACTH secretion appear to be mediated via the brain and corticotropin-releasing hormone (CRH). In the brain, there is good evidence that locally generated angiotensin II causes release of norepinephrine that in turn stimulates gonadotropin-releasing hormone-secreting neurons, increasing circulating luteinizing hormone. In addition, there is evidence that angiotensin II acts in the arcuate nuclei to increase the secretion of dopamine into the portal-hypophyseal vessels, inhibiting prolactin secretion. Central as well as peripheral angiotensin II increases CRH secretion, but there is little if any evidence that angiotensin II mediates the ACTH responses to other stressful stimuli.
...
PMID:Blood, pituitary, and brain renin-angiotensin systems and regulation of secretion of anterior pituitary gland. 834 4

Atrial and brain natriuretic peptides specifically bind to primary cultures of calf adrenal glomerulosa cells. Binding of both natriuretic peptides to the same receptor has been proved by: a Dixon plot showing competitive effects for the binding of 125I-labeled brain natriuretic peptide in the presence of increasing concentrations of unlabeled atrial natriuretic peptide; a Scatchard plot showing a lower dissociation constant (Kd) for atrial natriuretic peptide than for brain natriuretic peptide binding, but the maximum binding (Bmax) values were the same; autoradiography of sodium dodecyl sulfate polyacrylamide gels after cross-linking of 125I-labeled atrial natriuretic peptide and 125I-labeled brain natriuretic peptide, showing the same molecular weights for both peptide receptors--a single 66-kD band in whole cells and a main band at 125 kD in membranes. C-Type atrial natriuretic peptide only slightly displaced atrial natriuretic peptide binding. Angiotensin II- and potassium-mediated stimulation of aldosterone production were inhibited strongly and to the same degree by atrial and brain natriuretic peptide but only slightly by C-type atrial natriuretic peptide. Stimulation of aldosterone production mediated by adrenocorticotropin was only partially inhibited by atrial and brain natriuretic peptide, while baseline aldosterone was not affected. These results suggest that atrial and brain natriuretic peptide bind to the same receptors and provoke the same effects on aldosterone production. The weak effects found with C-type atrial natriuretic peptide suggest that the primary culture of calf adrenal glomerulosa cells contain the guanylate cyclase A receptor.
...
PMID:Adrenal receptors for natriuretic peptides and inhibition of aldosterone secretion in calf zona glomerulosa cells in culture. 839 12

In untreated congestive heart failure, aldosterone plasma concentrations are elevated in proportion to the severity of the disease and are further increased by the use of diuretic treatment. Angiotensin II, plasma potassium concentration, and corticotropin are the major stimulators of aldosterone synthesis. During angiotensin converting enzyme (ACE) inhibition, the role of alternative major or minor regulatory mechanisms may become significant. This may explain why during continuous ACE inhibition, after an initial reduction, plasma aldosterone measurements may subsequently increase to pretherapeutic levels. In addition to causing sodium and water retention, aldosterone contributes to hypokalaemia and hypomagnesaemia, which may induce electrical instability and death of cardiac myocytes. Aldosterone is also one factor involved in cardiac hypertrophy and fibrosis, which, together with myocardial cell death, may underlie progressive adverse myocardial remodelling. Evidence for a direct vascular effect of aldosterone suggests that this hormone may contribute to generalized vasoconstriction. Elevated plasma aldosterone levels can also contribute to depression of baroreflex sensitivity, and they are associated with increased mortality in patients with severe heart failure. Experimental and clinical research should be further expanded to investigate the potential benefits of opposing the effects of aldosterone by use of specific antagonists or other potentially more potent pharmacological agents with favourable side-effect profiles.
...
PMID:Aldosterone and heart failure. 868 70


<< Previous 1 2 3 4 5 Next >>