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Pharmacotherapy of Neurochemical Imbalances
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Rupali Patil, Aman Upaganlawar, Suvarna Ingale
Enkephalins are the natural opiate peptides recognized first in pig’s brain. Derived from the precursor proenkephalin, these peptides are present in the nerve endings in many parts of forebrain, substantia gelatinosa of brainstem, spinal cord, and GIT. Two types of enkephalins are known, leucine-enkephalin (YGGFL) and methionine enkephalin (YGGFM) (Sharma and Sharma, 2017).
Postulated Physiological and Pathophysiological Roles on Motility
Published in Edwin E. Daniel, Neuropeptide Function in the Gastrointestinal Tract, 2019
Hans-Dieter Allescher, Sultan Ahmad
Opium derivatives have been used almost since the third century B.C. as an antidiarrheal remedy because of their well-known constipating effect. The mode of action of exogenous opiates from various plants was clarified by the discovery of endogenous substances with opiate-like action in the pig brain by Hughes et al.411 and the isolation of “endorphins”.412 Endogenous opioid peptides are characterized by the typical N-terminal structure of enkephalins:
The Thymus and Immunotherapy, Reconstructive Vs. Stimulatory or Suppressive Conceptions
Published in Marek P. Dabrowski, Barbara K. Dabrowska-Bernstein, Immunoregulatory Role of Thymus, 2019
Marek P. Dabrowski, Barbara K. Dabrowska-Bernstein
Enkephalins are small peptides composed of five amino acids and originate from much larger precursor proenkephalin A composed of 236 amino acids. Endorphins originate from proopiomelanocortin (264 amino acids) and usually represent sequence of 16 to 31 amino acids. The enkephalins can also be synthesized chemically. The methionine-enkephalin (Met-Enk) represents structure of Tyr-Gly-Gly-Phe-Met with molecular weight of 573.65, and when obtained sterilely as a lyophilized powder (Union Chemique Belge, UCB Bioproduct, Brussels, Belgium) can easily be reconstituted with saline for clinical purposes. Physiologically, enkephalins are destroyed within 90 s by serum enkephalinase and aminopeptidase. The specific action of Naloxane on the cellular opioid receptors antagonize the effects of enkephalings. Earlier studies revealed that the functions of enkephalins are involved in the perception of pain and are influencing some behavioral activities, including mood, feeding, and drinking desire and memory learning.132,133
Urine N-terminal pro-B-type natriuretic peptide and plasma proenkephalin are promising biomarkers for early diagnosis of cardiorenal syndrome type 1 in acute decompensated heart failure: a prospective, double-center, observational study in real-world
Published in Renal Failure, 2022
Hong-Liang Zhao, Hai-Juan Hu, Xiu-Jie Zhao, Wei-Wei Chi, De-Min Liu, Qian Wang, Wei Cui
Amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is a well-known biomarker for the diagnosis and prognosis of ADHF, which has been linked to the occurrence and prognosis of CRS-1 [11–13]. However, most studies focused on blood NT-proBNP and none of them discussed urine NT-proBNP (uNT-proBNP) as a predictor of CRS-1 in ADHF patients. Enkephalin is an endogenous opioid peptide that regulates a variety of pathophysiological processes. Nevertheless, enkephalin is unstable and difficult to measure in plasma. As a precursor and surrogate marker of enkephalin, proenkephalin (PENK) is stable and simple to measure in plasma [14]. In recent years, PENK has gradually come into people’s awareness as a new biomarker for predicting the kidney dysfunction and prognosis in patients with ADHF [15,16]. However, it is still unknown whether PENK can early predict the occurrence of CRS-1. Therefore, this study first analyzes the uNT-proBNP and plasma PENK (pPENK) levels in ADHF patients on admission, explores whether they can early predict the occurrence of CRS-1, and finally evaluates the vulnerable-phase prognostic value of uNT-proBNP, pPENK, and CRS-1 for ADHF patients.
Pro-Enkephalin and its association with renal function in Middle Eastern immigrants and native Swedes
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2021
Christopher Nilsson, Anders Christensson, Peter M. Nilsson, Olle Melander, Louise Bennet
At present, numerous biomarkers have been identified in relationship to renal function as well as blood pressure. One in particular is Pro-Enkephalin (PENK), a precursor to enkephalin which is an opioid peptide that in 1975 was the first discovered endogenous peptide [8]. There are several different enkephalins, all of them are encoded by the PENK gene on chromosome 8 [9]. The biosynthesis of enkephalins involves several steps, among those, is the cleavage of the precursor PENK, which is produced throughout the human body in neuronal and in non-neuronal cells [10]. The physiological role of enkephalins is however unclear [11]. Previous studies have implicated a relation to renal function, as high plasma concentrations of PENK is associated with lower eGFR in various patient populations [12], although most thoroughly researched in subjects with acute myocardial infarction and sepsis [13–15].
Role of preovulatory concentrations of estradiol on timing of conception and regulation of the uterine environment in beef cattle
Published in Systems Biology in Reproductive Medicine, 2020
George A. Perry, Robert A. Cushman, Brandi L. Perry, Amanda K. Schiefelbein, Emmalee J. Northrop, Jerica J.J. Rich, Stephanie D. Perkins
Proenkephalin-A is the precursor of several individual enkephalins (Marx 1983). Transcript abundance of proenkephalin-A has been reported to increase fourfold during pregnancy in the rat uterus (Jin et al. 1988), and was increased by exposure to progesterone and decreased by exposure to RU486 (Cheon et al. 2002). Similarly, Jin and co-workers (1988) reported that expression in the rat uterus was greatest at metestrus and diestrus. In the current study, proenkephalin-A mRNA was not detected on Day 0 and was not different between treatments. However, expression increased from Day 5 to Day 10, then decreased to Day 16 of the cycle. This again supports the hypothesis that the uterus in the non-estrus animals may not be functioning properly to support proper embryo development and survival, even among proteins that are regulated by progesterone.