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)

Cultured cells from adult rat anterior pituitaries or intermediate lobes were treated with the proteinase inhibitor tripeptide aldehydes BOC-DPhe-Pro-Arg-H (Boc-fPRH) and DPhe-Pro-Arg-H (fPRH), ovine corticotropin-releasing factor (oCRF), and bromocriptine. One millimolar fPRH stimulated basal, and slightly enhanced oCRF-induced ACTH release by melanotrophs in short-term experiments. The basal release of alpha-MSH was also stimulated by the drug. In long-term experiments, fPRH elevated markedly both the release and the intracellular level of ACTH; BOC-fPRH caused an increased alpha-MSH release. Tritiated fPRH had no preference for POMC-producing cells and BOC-fPRH or fPRH were harmless to the cell morphology. In anterior pituitary cell cultures, fPRH diminished slightly basal and oCRF-induced ACTH release. Bromocriptine was ineffective on corticotrophs, however, in melanotrophs it inhibited ACTH release markedly with or without fPRH in the medium. The dissimilar responsiveness of the corticotrophs and melanotrophs to the peptide aldehydes may be interpreted in terms of their differing membrane receptors or intracellular mechanism of stimulus-secretion coupling.
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PMID:Dissimilar responsiveness of cultured corticotrophs and melanotrophs to tripeptide aldehydes. 301 10

We have previously demonstrated that intracerebroventricular (ICV) administration of oxytocin (OXY) enhanced grooming behaviors in male and female rats at a 1 microgram dose. In the present study female rats were injected ICV with 1 microgram OXY or equimolar doses of other peptides. At this dose arginine-vasopressin (AVP), arginine-vasotocin (AVT) and lysine-vasopressin (LVP), as well as alpha-MSH, were as effective as OXY in increasing grooming behavior. At equimolar doses, ACTH1-10, tocinoic acid (the ring structure of OXY) and Pro-Leu-Gly-NH2 (the tail structure of OXY) had no significant effect on grooming behavior. The potency of AVP and AVT was determined across a 0.05-5 microgram dose range. Grooming scores increased in an apparent linear manner across a similar OXY dose range. Both AVP and AVT, however, manifested an inverted U grooming response curve. Maximum grooming scores resulted from a 0.1 microgram dose of AVT or a 0.5 microgram AVP dose. Analyses of the aspects of grooming separately found that nonapeptides OXY, AVP and AVT all elevated body grooming, washing, and scratching. Because AVT and AVP administration resulted in grooming scores significantly higher than OXY at lower doses, we concluded that the CNS is more sensitive to the effects of AVT and AVP on grooming behavior than OXY.
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PMID:A comparison of grooming behavior potencies of neurohypophyseal nonapeptides. 301 15

We present a study of the cleavage specificity of IRCM-serine protease 1 from frozen porcine pituitary neurointermediate lobes using polypeptide substrates representing different segments of human pro-opiomelanocortin. Using 125I-labeled ACTH(11-24) and a 125I-labeled model beta-lipotropin (beta-LPH) peptide, the preference of this protease for cleavage C-terminal to the pairs of basic residues Lys-Arg and Lys-Lys was clearly seen. This study was extended to larger unlabeled natural human polypeptides including ACTH(1-39), beta-LPH(1-89), and the N-terminal glycopeptide (1-76), which are known to serve as substrates for further cleavage in vivo. In these substrates IRCM-serine protease 1 cleaved C-terminal to all pairs of basic residues known to be cleaved in vivo. In addition, the enzyme cleaved between two pairs of basic amino acids found in NT(1-76) which are also known to be cleaved in vivo. Many potential "tryptic-like" cleavage sites were not cleaved by the enzyme. However, IRCM-serine protease 1 cleaved C-terminal to Phe-Arg in the three melanocyte-stimulating hormone sequences of pro-opiomelanocortin. In order to better understand the physiological role of IRCM-serine protease 1, differential centrifugation was used to study the subcellular distribution of the enzyme from porcine pituitary anterior lobe homogenates. We present evidence that the active enzyme form, isolated from the subcellular fractions, possesses a similar molecular architecture as the enzyme isolated from frozen tissue (Mr 38,000 catalytic domain linked via disulfide bridge(s) to another polypeptide chain(s) to form an Mr 88,000 monomeric structure). The majority of IRCM-serine protease activity is found to be associated with small vesicles (150,000 X g for 5 h) of as yet undetermined nature. In addition, a latent activity was found to be associated with a 27,000 X g (15 min) pellet containing the majority of mature secretory granules. If IRCM-serine protease 1 participates in prohormone maturation in vivo, we propose a model in which this protease is present in an enzymatically active form in small vesicles, possibly within clathrin-coated structures (prosecretory granules) which are then transformed to mature secretory granules by a process which would also inactivate most of the enzyme.
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PMID:Selective cleavage of human ACTH, beta-lipotropin, and the N-terminal glycopeptide at pairs of basic residues by IRCM-serine protease 1. Subcellular localization in small and large vesicles. 301 45

The effects of peripheral injection of arginine vasopressin (AVP), oxytocin (OT), arginine vasotocin (AVT), adrenocorticotrophic hormone (ACTH4-10) and alpha-melanocyte-stimulating hormone (alpha-MSH) were studied, using pigeon subjects and a pair comparison task, with and without intervening delays between stimuli presentation. The highest dose (20 micrograms/kg) of AVT impaired performance by disrupting input, but not storage. General cognitive ability was unimpaired, as were perceptual mechanisms. None of the other peptides affected recognition memory, in that forgetting curves were unchanged when compared with control. The results are discussed in terms of species-specific roles for these peptides.
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PMID:Effects of peripherally injected pituitary peptides on recognition memory in pigeons. 301 46

The occurrence of intermediates from the processing of ACTH-(1-39) [adrenocorticotropic hormone-(1-39)] to alpha-melanocyte-stimulating hormone was investigated in normal pig pituitaries by the use of sensitive and specific radioimmunoassays for ACTH-(1-13), ACTH-(1-14), ACTH-(1-13)-NH2 and ACTH-(1-39). Fractionation by reverse-phase h.p.l.c. revealed ACTH(1-17) and their acetylated analogues. The intermediate lobe contained NO-diacetyl-ACTH-(1-13)-NH2, N-acetyl-ACTH-(1-13)-NH2 and ACTH-(1-13)-NH2. In addition, the corresponding ACTH-(1-14) peptides (the glycine-extended precursor of the amidated peptides) were detected in lower amounts in both the intermediate lobe and the anterior lobe. ACTH-(1-17), ACTH-(1-13) and their acetylated analogues could not be detected in the anterior lobe or the intermediate lobe. The results suggest that an endopeptidase initially cleaves ACTH-(1-39) at the Lys-16-Arg-17 bond. ACTH-(1-16) is then processed by a pituitary carboxypeptidase to ACTH-(1-14) and ACTH-(17-39) by the aminopeptidase to ACTH-(18-39).
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PMID:alpha-Melanocyte-stimulating-hormone precursors in the pig pituitary. 301 6

The neuropeptides arginine vasopressin and oxytocin are generated from their prohormones in the hypothalamoneurohypophysial system by enzymatic cleavages at paired basic residues (i.e. Lys-Arg). This study describes the purification of an enzyme from bovine neural lobe secretory vesicles, the putative site of this processing, which is capable of cleaving several prohormones at paired basic residues. The enzyme is a glycoprotein of Mr approximately 70,000 and has an acidic pH maximum. It processes the heterologous precursors pro-opiomelanocortin and insulin at paired basic residues in a manner similar to a pro-opiomelanocortin-converting enzyme derived from bovine intermediate lobe secretory vesicles which has been described previously. In addition, the neural lobe-derived converting enzyme cleaves the human vasopressin prohormone in vitro to yield arginine vasopressin-Gly10-Lys11-Arg12 as the major vasopressin cleavage product. This indicates that the enzymatic cleavage in the vasopressin precursor occurred primarily on the carboxyl side of the arginine in the pair of Lys-Arg basic residues separating the vasopressin peptide from the neurophysin moiety in the precursor. The properties of the neural and intermediate lobe-derived enzymes are virtually identical, raising the possibility that a family of similar enzymes may be responsible for cleaving a number of prohormones at paired basic residues in different tissues.
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PMID:Purification and characterization of a paired basic residue-specific prohormone-converting enzyme from bovine pituitary neural lobe secretory vesicles. 302 39

IRCM-Serine Protease 1 (IRCM-SP1) has recently been isolated and characterized from porcine pituitary anterior and neurointermediate lobes (Cromlish et al., 1986a, J. Biol. Chem. 261:10850-10858; Cromlish et al., 1986b, J. Biol. Chem. 261:10859-10870). This pituitary serine protease was shown to selectively cleave human pro-opiomelanocortin (POMC)-derived peptides at both pairs of basic residues and C-terminal to specific Arg residues, all known to be cleaved in vivo. Here, a similar enzyme was isolated from rat heart atria and ventricles. Rat IRCM-SP1 was shown to be highly specific for the same cleavage sites in POMC, as the porcine pituitary homologue. Furthermore, the rat and the porcine enzymes cleave rat pro-Atrial Natriuretic Factor (pro-ANF 1-126) to yield ANF 103-126, 102-126 and 99-126 in that order of preference. This suggests that in vitro the cleavage sites preferred in pro-ANF resemble those found in brain and hypothalamus. The enzyme is nine times more abundant in atria versus ventricles/mg protein. It is concluded that IRCM-SP1, could well represent a common pro-hormone maturation enzyme for POMC and Pro-ANF and possibly many other pro-hormones.
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PMID:Homologous IRCM-serine protease 1 from pituitary, heart atrium and ventricle: a common pro-hormone maturation enzyme? 302 26

Opiates stimulate the growth hormone and prolactin responses to stimuli in non-obese humans. Obese patients, however, show lowered growth hormone and prolactin responses and raised beta-endorphin levels. We therefore investigated the effect of the opiate antagonist naloxone on the stimulated growth hormone and prolactin secretions in a controlled double-blind study in obese patients. All patients received 200 micrograms TRH and 0.5 g/kg b.w. arginine together with 2 mg of naloxone or placebo i.v. in a randomized sequence. The TRH- and arginine-induced increases in prolactin and growth hormone were significantly greater after administration of naloxone (p less than 0.05). Naloxone also produced a significant increase in ACTH, cortisol and beta-endorphin when compared with placebo. TSH, triiodothyronine, thyroxine, insulin, glucagon and blood glucose showed no significant differences between both days of the trial. The effect of naloxone on growth hormone and prolactin secretions in obese humans can thus be regarded as a partial normalization. We therefore conclude that the hypothalamic regulatory disturbance of growth hormone and prolactin secretions in the obese could be caused by raised opiate levels.
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PMID:Naloxone increases the response of growth hormone and prolactin to stimuli in obese humans. 303 2

The secretion of Corticotropin-Releasing Factor (CRF) and Arginine Vasopressin (AVP) into sheep hypothalamo-hypophysial portal blood was investigated in conscious, unrestrained castrated rams. One to two hours after the onset of the collection, peripheral ACTH and cortisol levels were within the basal range in all the animals and portal CRF and AVP concentrations were low ranging between 5 and 90 pg/ml. After acute hemorrhage, a sharp increase in portal CRF and AVP was observed, inducing a sustained elevation of peripheral ACTH and cortisol. These data show that measurements of CRF and AVP in the portal blood of conscious sheep provide a good methodology to study the regulation of basal and stress-induced ACTH secretion.
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PMID:Secretion of corticotropin releasing factor (CRF) and vasopressin (AVP) into the hypophysial portal blood of conscious, unrestrained rams. 304 63

In search of early pregnancy factors, we detected by radioimmunoassay the presence of enkephalin in bovine and human corpus luteum. In vitro met-enkephalin release by bovine corpus luteum is about 0.5 to 1 pmole/mg of fresh tissue/24 hrs. The content of the fresh tissue is between 0.7 and 1.9 pmoles per gram of human tissue, and 0.9 pmoles for bovine tissue. Furthermore, we determined the presence of leu-enkephalin and met-enkephalin Arg-Gly-Leu to. The ratios observed confirm a pro-enkephalin A expression in the ovary. Opiates or opioid-like peptides are present in the female genitalia at the time of early embryo development. The roles of these opioid peptides is discussed in term of ovum transport, granulosa cell physiology and early pregnancy factors.
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PMID:[Production of enkephalins by the human and bovine corpus luteum]. 310 27


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