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

Corticotropin-Releasing Factor (CRF) activity was determined (dispersed pituitary cell assay) in rat median eminence (ME), various hypothalamic nuclei, as well as in entire median basal hypothalamus (MBH) and extra-hypothalamic areas. Highest concentrations were seen in ME, with decreased concentrations noted proceeding dorsally and cephalad from ME. Potency (NIAMDD HE-RP-1, ME reference extract, equivalent to 1.0) estimates were: ME-2.2; arcuate n.-0.88; dorsomedial n.-041; ventromedial n.-0.35; periventricular n.-0.24; hypothalamus-0.05; thalamus-0.01; cortex-0.005. Measurable, but lesser amounts, than in the above cited nuclei, were present in supraoptic and paraventricular nuclei. CRF activity was not measurable in preoptic area, septum, olfactory bulb, striatum, mesencephalon, pons, medulla or cerebellum. Complete hypothalamic deafferentation was accompanied by an increase in CRF activity/mug protein in ME and MBH, associated with decreased AM plasma ACTH and corticosterone concentrations. CRF-like activity in ME and MBH increased following hypophysectomy and after dexamethasone pretreatment. These findings indicate that CRF is mainly synthesized in the ME and surrounding area, and this source of CRF is sensitive to feedback effects and that extrahypothalamic inputs affect CRF release. Female animals had higher ME CRF content than did male animals. Homozygous and heterozygous Brattleboro rats had significantly less CRF in ME and MBH than did control animals, with significant differences also noted between homozygous and heterozygous animals.
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PMID:Corticotropin releasing factor distribution in normal and Brattleboro rat brain, and effect of deafferentation, hypophysectomy and steroid treatment in normal animals. 1 88

Intrajugular administration of LHRH (0-6 and 1-2 mug) in hypophysectomized rats which received renal grafts of anterior pituitary induced a small but significant rise in plasma GH 5 and 10 min post-treatment. LHRH, at the same dose levels, was ineffective in weight-matched intact controls. MIF, at the dose of 1-2 mug, induced a slight GH rise 5 min after treatment in hypophysectomized trasnplanted rats, while it was ineffective in intact controls. Unlike the two hypothalamic peptides, alpha-MSH (0-6 and 1-2 mug) was ineffective as a GH-releaser in both transplanted and intact rats.
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PMID:Stimulation of growth hormone release by luteinizing hormone-releasing hormone and melanocyte-stimulating hormone-release inhibiting hormone in the hypophysectomized rat bearing an ectopic pituitary. 1 96

Systematic analysis of the hydrolysis of benzyloxycarbonyl (Cbz)-dipeptides by cathepsin A [EC 3.4.12.1] purified from rat liver lysosomes showed that multiple forms of cathepsin A preferentially cleave peptide bonds with leucine, methionine, and phenylalanine. Cbz-Met-Met, -Met-Phe, -Phe-Met, and -Phe-Ala were hydrolyzed 6 to 8 times faster than the standard substrates, Cbz-Glu-Phe and Cbz-Glu-Tyr. The pH optima of the hydrolyses were 4.6 to 5.8. Hydrolysis of peptide bonds with glycine, isoleucine, and proline was very slow, but the rate depended on the nature of the adjacent amino acids. Proteins such as albumin, cytochrome c, gamma-globulin, hemoglobin, histone, myoglobin, and myosin were scarecely degraded. Peptide hormones, such as glucagon and adrenocorticotropic hormone (ACTH) were hydrolyzed markedly with optimum pH's of 4.5 and 4.6, respectively. Angiotensin I, II, bradykinin, Lys- and Met-Lysbradykinin (kallidin and Met-kallidin), and substance P were also hydrolyzed at appreciable rates. pH optima for these peptide hormones were 5.2 to 5.6. On the other hand, insulin and its A chain, luteinizing hormone-releasing hormone (LH-RH), oxytocin and vasopressin were cleaved slowly. In the hydrolyses of glucagon and other peptides, multiple forms of rat liver lysosomal cathepsin A again showed a carboxypeptidase nature, cleaving peptide bonds sequentially from the carboxyl terminal. Almost all of the amino acids were cleaved on prolonged incubation. Vaso-activites of angiotensin II and bradykinin were rapidly lost on hydrolysis by cathepsin A. Lysosomal cathepsin C [dipeptidylaminopeptidase I, EC 3.4.14.1] also activated angiotensin II, but did not inactive bradykinin. Cathepsin A, therefore, can be regarded as one of the lysosomal angiotensinases and kinases. No distinct differences were observed between the multiple forms of cathepsin A in these hydrolyses and inactivations of peptides.
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PMID:Studies on cathepsins of rat liver lysosomes. III. Hydrolysis of peptides, and inactivation of angiotensin and bradykinin by cathepsin A. 1 61

Male, albino rats were treated with alpha-MSH, MSH/ACTH 4-10, MIF-I or a diluent control solution and then tested on a visual discrimination problem. Immediately after acquistion of the visual task the animals were tested with a spatial extradimensional shift problem. The animals treated with the MSH/ACTH 4-10 and MIF-I acquired the discrimination nonsignificantly faster than animals treated with alpha-MSH or a placebo. A subproblem analysis of the EDS behavior indicated that the peptides significantly improved performance probably by affecting attention.
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PMID:Influence of three short-chain peptides (alpha-MSH, MSH/ACTH 4-10, MIF-I on) dimensional attention. 1 9

Previous reports have indicated that alpha-MSH release inhibiting hormone (MIF-1) increased the behavior occurring as a result of the dihydroxyphenylalanine (DOPA) potentiation test [3,7]. This study was undertaken to see whether dopamine (DA) or norepinephrine (NE) levels likewise increased in the test animals. The DOPA potentiation test was performed as follows: 2-4 hr before behavior measurement, 40 mg/kg of the monoamine oxidase inhibitor pargyline HCl was given orally. Two hr later this was followed by the intraperitoneal (IP) injection of MIF-1 at doses of 0.1, 0.3 or 1.0 mg/kg. Behavioral measurement was begun after the IP injection of 200 mg/kg of dl-DOPA 1-2 hr after the MIF-1. The parameters included social interaction, aggressiveness, fighting, ataxia, jumping, defecation, urination and salivation. The animals were beheaded while the behavior was still increased and the striatal area removed, placed in aluminum foil, and kept at -50 degrees C until assayed. In general, especially among the younger animals, a significant correlation (p=0.05 to p=0.01) was found between the increased behavioral responses to MIF-I and the rise in DA. Because of a few exceptions to this correlation the possibility is suggested that MIF-I might also affect behavior by acting directly on the postsynaptic membrane thus bypassing any change in NE or DA which is known to increase cycli AMP in the striatum.
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PMID:Possible association of increased rat behavioral effects and increased striatal dopamine and norepinephrine levels during the DOPA-potentiation test. 1 11

Subcutaneous administration of ACTH 1-24 to mice increased the incorporation of [3H]lysine into brain and liver proteins, an effect which resembled that due to footshock. Corticosterone administration did not mimic these effects. ACTH 4-10 increased the [3H]lysine incorporation into brain or liver. These results are consistent with ACTH mediating the effects of footshock. However, dexamethasone decreased the brain responses to both footshock and ACTH, but while the liver response to ACTH was blocked, the footshock response was only diminished. This suggests a neural component in the response of the liver and possibly the brain. Intraventricular administration of ACTH 1-24 or ACTH 4-10 (D-phe), but not ACTH 4-10, increased [3H]lysine incorporation into brain protein. These neurochemical responses parallelled a distinctive pattern of behavior characterized by stretching, yawning and excessive grooming. Treatment for 3 days with long-acting preparations of ACTH 4-10, ACTH 4-10 (D-phe) or ACTH 1-24 increased the conversion of [3H]tyrosine into dopamine but not norepinephrine, alpha-MSH, beta-MSH or LVP had no such effect. Similar treatment with ACTH 4-10 or ACTH 1-24 increased striatal tyrosine hydroxylase activity measured in vitro, but did not significantly alter the enzyme activity from other brain regions. We conclude that ACTH peptides can stimulate protein and dopamine metabolism in mouse brain and that LVP has no such effects.
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PMID:Neurochemical responses of mice to ACTH and lysine vasopressin. 1 13

The intracarotid artery quick injection technique of Oldendorf was utilized to determine the Brain Uptake Index (BUI) of radio-labeled peptides in comparison with 3H2O or 14C-antipyrine as counterlabels. The normalized BUI values for 3H-MIF-I, 3H-alpha-MSH and 14C-AVP were 13.7, 9.6 and 13.0 respectively at 15 sec after injection consistent with their having readily penetrated the blood-brain barrier. The BUI values were similar, though somewhat increased, at 10 min postinjection consistent with their ready exit across the blood-brain barrier. At 15 sec after injection 0.5+/-0.1%/g brain of the originally injected peptide label was recovered; and 0.1+/-0.2%/g brain was recovered after 10 min. The label was distributed uniformly in the major brain regions at both times. However, the percentage of the originally injected label/g of pineal and pituitary gland tissue was 10-20 X increased as compared with the major brain regions as would be expected by their location outside the blood-brain barrier. The in vitro uptake of the radio-labeled peptides by synaptosomes prepared from the whole brain and the major brain regions was passive; it was not temperature dependent, nor was it Na+ dependent. However, the binding of the three peptides by the synaptosomes varied considerably: AVP greater than MSH greater MIF: 50 greater than 5 greater 1. The penetratin of the blood-brain barrier by the three peptides is consistent with their having CNS effects.
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PMID:Peptides readily penetrate the blood-brain barrier: uptake of peptides by synaptosomes is passive. 1 14

This paper reviews recent evidence that a number of small peptides found in the brain are active in the central nervous system and behaviorally. Attention is focused on MSH/ACTH 4-10, alpha- and beta-MSH, and the prohormone beta-LPH, as they produce a syndrome of yawning and stretching. Studies with substance P and mainly with MIF-I are also reviewed. It is shown that substance P is an excitatory transmitter or modulator in the dorsal spinal cord with that MIF-I has antiparkinson properties. It is concluded that many polypeptides have direct actions on the central nervous system independent of their neuroendocrine properties.
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PMID:Neurologically active peptides. 1 15

In 15 patients with congenital adrenal hyperplasia, the corticotrophic and melanotrophic functions were evaluated by plasma ACTH and beta-MSH radioimmunoassay. Evaluation of the corticotrophic and melanotrophic functions was also performed in 3 subjects after provocative tests (insulin-induced hypoglycaemia, metyrapone) and in 5 subjects after infusion of synthetic MIF (MSH-release inhibiting factor). The results indicate a significant increase in plasma ACTH and beta-MSH in CAH. In addition, we found that although in most cases there was a significant positive correlation between the plasma ACTH and beta-MSH levels, in some only the plasma ACTH values were high and beta-MSH values normal. No other anomalies of the corticotrophic and melanotrophic functions occurred in CAH as shown by the results of the provcative tests. Lastly, it must be emphasized that no modifications of plasma beta-MSH after synthetic MIF infusion were found in subject with normal or high plasma beta-MSH. These findings induce us to consider it unlikely that synthetic MIF is active in man.
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PMID:Corticotrophic and melanotrophic functions in congenital adrenal hyperplasia. 1 24

Intermediate lobes from Rana esculenta pituitary glands were continuously superfused for 7 hrs at 28 degrees C with amphibian culture medium. alpha-MSH release was measured by use of a sensitive double antibody radio-immunoassay system. alpha-MSH secretion was inhibited by low temperatures. A large increase in alpha-MSH release was observed when Thyrotropin Releasing Hormone (TRH) at doses ranging from 10(-9) to 10(-7) molar was added to the superfusion medium. Since large amounts of TRH are to be found in the hypothalamus of amphibians but have no effect over pituitary TSH secretion, the action of TRH over alpha-MSH release may have a physiological significance.
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PMID:[Control of pituitary secretion of melanotropin in an anuran amphibian by thyrotropin releasing factor (TRH). Study in vitro]. 1 4


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