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Research library — page 24

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RPEP-01376 · 2008

Novel Fluorinated Amino Acid Incorporated Into GHRP for Improved Drug Properties

A novel difluorophenylalanine analog was incorporated into GHRP, maintaining GHS-R activity while introducing fluorine-mediated metabolic stability improvements — demonstrating unnatural amino acid incorporation for enhancing GH secretagogue drug properties.

Li, Jun; Chen, Stephanie Y; Murphy, Brian J; Flynn, Neil; Seethala, Ramakrishna; Slusarchyk, Dorothy; Yan, Mujing; Sleph, Paul; Zhang, Hongjian; Humphreys, William G; Ewing, William R; Robl, Jeffrey A; Gordon, David; Tino, Joseph A · In Vitro

RPEP-01377 · 2008

Gallium-68 Labeled RGD Peptides: Imaging Tumors Without a Cyclotron

Gallium-68 labeled RGD peptides successfully imaged tumors in mice by targeting integrin αvβ3, a protein overexpressed on tumor blood vessels. Three versions were tested — single (RGD1), double (RGD2), and quadruple (RGD4) RGD peptide constructs. The dimeric version (68Ga-NOTA-RGD2) emerged as the best candidate, achieving 2.8% ID/g tumor uptake at 1 hour with favorable tumor-to-background ratios (4.4 tumor/muscle, 2.0 tumor/liver, 1.1 tumor/kidney). The quadruple version (RGD4) had the highest tumor uptake but also accumulated heavily in the kidneys, making it less suitable for clinical use. All three constructs could be labeled with 68Ga within 10 minutes, a major practical advantage since 68Ga comes from a generator (no cyclotron needed).

Li, Zi-Bo; Chen, Kai; Chen, Xiaoyuan · Animal

RPEP-01380 · 2008

Different Milk-Derived Peptides Work Better Together: Synergistic Antimicrobial Effects

Combinations of milk-derived antimicrobial peptides and proteins (lactoferricin + lysozyme, lactoferrin + alpha-lactalbumin peptides) showed synergistic antibacterial activity exceeding individual effects — the natural milk cocktail is more effective than any single component.

López-Expósito, I; Pellegrini, A; Amigo, L; Recio, I · In Vitro

RPEP-01384 · 2008

Antibody That Destroys Ghrelin Increases Metabolism and Reduces Refeeding in Mice

A ghrelin-degrading catalytic antibody (ghrelin-ase) increased metabolic rate and reduced post-fast refeeding in mice, demonstrating an immunological approach to ghrelin neutralization for obesity treatment — antibody-based appetite suppression.

Mayorov, Alexander V; Amara, Neri; Chang, Jason Y; Moss, Jason A; Hixon, Mark S; Ruiz, Diana I; Meijler, Michael M; Zorrilla, Eric P; Janda, Kim D · Animal Study

RPEP-01387 · 2008

A Cell-Penetrating Antioxidant Peptide Protects Kidneys From Obstruction Damage

Cell-permeable antioxidant peptide (SS-31 family) reduced renal tubular apoptosis, oxidative damage, and fibrosis in unilateral ureteral obstruction rats — expanding mitochondria-targeted peptide therapy to kidney protection for obstructive and other renal diseases.

Mizuguchi, Yasunori; Chen, Jie; Seshan, Surya V; Poppas, Dix P; Szeto, Hazel H; Felsen, Diane · Animal Study

RPEP-01388 · 2008

BNP Predicts 3-Year Outcomes in Chagas Disease Heart Involvement

Natriuretic peptides (BNP, NT-proBNP) predicted 3-year cardiovascular events and mortality in Chagas disease patients, establishing them as prognostic biomarkers for Chagas cardiomyopathy — a major neglected tropical disease affecting millions.

Moreira, Maria da Consolação V; Heringer-Walther, Silvia; Wessel, Niels; Moreira Ventura, Tiago; Wang, Yong; Schultheiss, Heinz-Peter; Walther, Thomas · Cohort

RPEP-01392 · 2008

MK-677 for 1 Year in Healthy Elderly: Increased Lean Mass But Also Fat and Insulin

One year of oral MK-677 in healthy older adults (n=65) increased fat-free mass (+1.1 kg), GH, and IGF-1 but also increased fat mass, fasting glucose, and insulin resistance — the most comprehensive long-term RCT showing MK-677's mixed metabolic profile in aging.

Nass, Ralf; Pezzoli, Suzan S; Oliveri, Mary Clancy; Patrie, James T; Harrell, Frank E; Clasey, Jody L; Heymsfield, Steven B; Bach, Mark A; Vance, Mary Lee; Thorner, Michael O · RCT

RPEP-01394 · 2008

BPC-157 Heals Muscle Crush Injury in Rats

BPC-157 accelerated healing of muscle crush injury in rats with improved functional recovery and histological regeneration, demonstrating efficacy for acute traumatic muscle damage — expanding its musculoskeletal healing applications beyond tendon and clean transection injuries.

Novinscak, Tomislav; Brcic, Luka; Staresinic, Mario; Jukic, Ivana; Radic, Bozo; Pevec, Danira; Mise, Sandro; Tomasovic, Sanja; Brcic, Iva; Banic, Tihomir; Jakir, Ana; Buljat, Gojko; Anic, Tomislav; Zoricic, Ivan; Romic, Zeljko; Seiwerth, Sven; Sikiric, Predrag · Animal Study

RPEP-01395 · 2008

Combining GLP-1 Drugs With Other Diabetes Medications: What Works Best

GLP-1 agonists and DPP-4 inhibitors combine synergistically with metformin (first-line), sulfonylureas, thiazolidinediones, and insulin for T2DM, with combination selection guided by patient weight, hypo risk, and HbA1c target — practical combination pharmacotherapy guidance.

Over, Rebecca K; Ratner, Robert E · Review

RPEP-01396 · 2008

How Your Body's Own Peptide LL-37 Stops Bacteria from Building Protective Biofilms

The human host defense peptide LL-37 potently inhibited Pseudomonas aeruginosa biofilm formation at a concentration of just 0.5 µg/ml — 128 times lower than the dose needed to kill bacteria outright (MIC = 64 µg/ml). This means LL-37 doesn't need to act as a direct antibiotic to fight infection; it can prevent bacteria from building the protective biofilm communities that make chronic infections so difficult to treat. LL-37 also disrupted pre-existing biofilms and worked through multiple mechanisms: reducing bacterial attachment to surfaces, stimulating twitching motility (which keeps bacteria from settling), and downregulating quorum sensing genes in the Las and Rhl systems that bacteria use to coordinate biofilm construction.

Overhage, Joerg; Campisano, Andrea; Bains, Manjeet; Torfs, Ellen C W; Rehm, Bernd H A; Hancock, Robert E W · In Vitro

RPEP-01397 · 2008

Aldosterone Levels During Heart Attack Hospitalization Predict Long-Term Survival

Plasma aldosterone levels during MI hospitalization independently predicted post-discharge survival, with higher aldosterone indicating worse prognosis — adding aldosterone to BNP and other neurohormones for comprehensive post-MI risk stratification.

Palmer, Barry R; Pilbrow, Anna P; Frampton, Christopher M; Yandle, Tim G; Skelton, Lorraine; Nicholls, M Gary; Richards, A Mark · Cohort

RPEP-01398 · 2008

PYY3-36 First Suppresses Then Stimulates Appetite: A Biphasic Response Not Seen With GLP-1

PYY3-36 injection produced biphasic appetite response: acute anorexia followed by delayed orexigenic rebound, unlike GLP-1 which showed sustained anorexia — this rebound effect may limit PYY3-36's obesity drug potential compared to GLP-1 agonists.

Parkinson, James R C; Dhillo, Waljit S; Small, Caroline J; Chaudhri, Owais B; Bewick, Gavin A; Pritchard, Iain; Moore, Stanley; Ghatei, Mohammed A; Bloom, Stephen R · Animal Study

RPEP-01399 · 2008

Korean Pine Nut Oil Triggers CCK Release and Reduces Appetite in Postmenopausal Women

Korean pine nut oil stimulated CCK-8 release and reduced appetite desire and prospective food consumption in overweight postmenopausal women (RCT), demonstrating a food-derived natural CCK secretagogue for appetite management.

Pasman, Wilrike J; Heimerikx, Jos; Rubingh, Carina M; van den Berg, Robin; O'Shea, Marianne; Gambelli, Luisa; Hendriks, Henk F J; Einerhand, Alexandra W C; Scott, Corey; Keizer, Hiskias G; Mennen, Louise I · RCT

RPEP-01400 · 2008

Both Sex and Body Weight Together Determine How Well GH Peptide Combinations Work

GHRH/GHRP-2 synergy for GH secretion was jointly determined by gonadal status (greater in women) and BMI (reduced in obesity), demonstrating that sex hormone environment AND body composition together modulate GH secretagogue combination effectiveness.

Paulo, Remberto C; Cosma, Mihaela; Soares-Welch, Cacia; Bailey, Joy N; Mielke, Kristi L; Miles, John M; Bowers, Cyril Y; Veldhuis, Johannes D · Clinical Trial

RPEP-01403 · 2008

How CRF Binds Its Receptor: The Molecular Recognition of the Stress Peptide

CRF-CRFR1 molecular recognition involves a two-step binding model: C-terminal CRF helix binds the receptor N-terminus (affinity), then N-terminal CRF contacts the receptor core (activation) — structural basis for designing CRF receptor-selective drugs.

Pioszak, Augen A; Parker, Naomi R; Suino-Powell, Kelly; Xu, H Eric · In Vitro

RPEP-01404 · 2008

GH Peptides Restore Stomach Motility in Diabetic Mice With Gastroparesis

Ghrelin and GHRP-6 restored gastric contractile activity and emptying in diabetic gastroparesis mice, with effects mediated through smooth muscle and neural pathways — confirming GH secretagogues as gastroprokinetic agents for diabetic GI dysfunction.

Qiu, Wen-Cai; Wang, Zhi-Gang; Wang, Wei-Gang; Yan, Jun; Zheng, Qi · Animal Study

RPEP-01405 · 2008

Ghrelin and GHRP-6 Improve Diabetic Gastroparesis by Restoring Stomach Emptying

Ghrelin and GHRP-6 restored gastric emptying in streptozotocin-diabetic rats with gastroparesis, improving gastric motility through GHS-R activation — validating GH secretagogues as therapeutic agents for diabetic gastroparesis, a common and debilitating complication.

Qiu, Wen-cai; Wang, Zhi-gang; Wang, Wei-gang; Yan, Jun; Zheng, Qi · Animal Study

RPEP-01412 · 2008

Natriuretic Peptide Blood Tests Detect Heart Problems in Elderly Outpatients

Plasma natriuretic peptides (ANP, BNP, NT-proBNP) correlated with echocardiographic abnormalities (LV dysfunction, LVH, diastolic dysfunction) in geriatric outpatients — supporting NP screening for subclinical cardiac disease detection in the elderly.

Rutten, Joost H W; van der Velde, Nathalie; van der Cammen, Tischa J M; ten Cate, Folkert J; Vletter, Wim B; Boomsma, Frans; van den Meiracker, Anton H · Cross Sectional

RPEP-01414 · 2008

VIP Gene Is Key to Lung Blood Vessel Remodeling and Pulmonary Inflammation

VIP gene expression was essential for normal pulmonary vascular regulation, with VIP knockout mice developing spontaneous pulmonary hypertension and vascular remodeling — establishing VIP as an endogenous protective factor against pulmonary vascular disease.

Said, Sami I · Animal Study

RPEP-01416 · 2008

Endomorphin-2's Supraspinal Pain Relief Involves Releasing Dynorphin A Through Mu-1 Receptors

Supraspinal endomorphin-2 antinociception involved dynorphin A release mediated by mu-1 receptors in the brain, with anti-dynorphin antibodies partially blocking the effect — confirming endomorphin-2's unique dual-pathway (mu + dynorphin) analgesic mechanism.

Sakurada, Shinobu; Sawai, Toshiki; Mizoguchi, Hirokazu; Watanabe, Hiroyuki; Watanabe, Chizuko; Yonezawa, Akihiko; Morimoto, Masaya; Sato, Takumi; Komatsu, Takaaki; Sakurada, Tsukasa · Animal Study

RPEP-01418 · 2008

MK-677 Does NOT Slow Alzheimer's Disease Progression Despite Raising GH and IGF-1

MK-677 successfully increased GH/IGF-1 in AD patients but showed no clinical benefit on cognitive decline, ADAS-cog, or CDR-sb over the trial period — proving GH axis restoration alone is insufficient for treating established Alzheimer's disease.

Sevigny, J J; Ryan, J M; van Dyck, C H; Peng, Y; Lines, C R; Nessly, M L · RCT

RPEP-01421 · 2008

Combined GHRH + GHRP-6 Test Is the Best for Evaluating GH Deficiency in Clinical Settings

Combined GHRH + GHRP-6 stimulation test demonstrated the highest sensitivity and specificity for GH deficiency evaluation compared to individual agents, establishing it as the recommended clinical provocative test for GH secretory capacity assessment.

Spiliotis, Bessie E; Papadimitriou, Dimitrios T; Alexandrides, Theodore K; Karystianos, Christoforos; Nikiforidis, George; Vassilakos, Pavlos; Beratis, Nicholas G; Casanueva, Felipe F · Clinical Trial

RPEP-01423 · 2008

Are MS and ALS Caused by Autoimmunity Against the Brain's Own Neuropeptides?

Autoimmune attack on endogenous vasoactive neuropeptides (VIP, PACAP, CGRP) is proposed as a pathogenic mechanism for MS and ALS, with detection of anti-neuropeptide antibodies and correlation with disease activity — neuropeptide autoimmunity as neurodegeneration cause.

Staines, Donald R · Review

RPEP-01424 · 2008

Could Autoimmunity Against Eye Neuropeptides Cause Retinal Disease in Humans?

Autoimmune targeting of vasoactive neuropeptides (VIP, PACAP) in retinal vessels may cause retinopathy through impaired local blood flow autoregulation — proposing neuropeptide autoimmunity as a mechanism for vascular retinal diseases including diabetic retinopathy.

Staines, Donald R · Review

RPEP-01425 · 2008

A New Endomorphin-Like Peptide Discovered in the Rat Brain

A novel endomorphin-2-like immunoreactive peptide was detected in rat brain extracts with different chromatographic properties from known endomorphin-2, potentially representing a new endogenous mu-opioid peptide or modified form — expanding the endogenous opioid catalog.

Szemenyei, Erzsébet; Barna, István; Mergl, Zsuzsa; Keresztes, Attila; Darula, Zsuzsanna; Kató, Erzsébet; Tóth, Géza; Rónai, András Z · In Vitro

RPEP-01426 · 2008

Comparing Methods for Testing Antimicrobial Peptide Activity: A Lactoferricin Case Study

Comparative analysis of broth dilution, radial diffusion, and flow cytometry methods for antimicrobial peptide testing using lactoferricin derivatives showed significant method-dependent activity variations — establishing the need for standardized peptide antimicrobial testing.

Sánchez-Gómez, Susana; Lamata, Marta; Leiva, José; Blondelle, Sylvie E; Jerala, Roman; Andrä, Jörg; Brandenburg, Klaus; Lohner, Karl; Moriyón, Ignacio; Martínez-de-Tejada, Guillermo · In Vitro

RPEP-01427 · 2008

Prolactin-Releasing Peptide Naturally Reduces Food Intake in Rodents

PrRP-deficient mice showed increased food intake and body weight, while PrRP administration reduced feeding, establishing endogenous prolactin-releasing peptide as a novel satiety signal acting through hypothalamic and brainstem appetite circuits.

Takayanagi, Yuki; Matsumoto, Hirokazu; Nakata, Masanori; Mera, Takashi; Fukusumi, Shoji; Hinuma, Shuji; Ueta, Yoichi; Yada, Toshihiko; Leng, Gareth; Onaka, Tatsushi · Animal Study

RPEP-01428 · 2008

Oxidative Stress Reduces Adiponectin in Heart Failure: Another Piece of the Metabolic Puzzle

Plasma oxidative stress markers inversely correlated with adiponectin levels in CHF patients, with low adiponectin associated with worse outcomes — oxidative stress suppresses the protective adipokine adiponectin, adding metabolic dysfunction to heart failure pathophysiology.

Tanaka, Toshinari; Tsutamoto, Takayoshi; Nishiyama, Keizo; Sakai, Hiroshi; Fujii, Masanori; Yamamoto, Takashi; Horie, Minoru · Cross Sectional

RPEP-01429 · 2008

An Arachidonic Acid Metabolite Kills Pain by Releasing Beta-Endorphin and Met-Enkephalin

14,15-Epoxyeicosatrienoic acid (EET) produced antinociception mediated by beta-endorphin and met-enkephalin release (confirmed by antisera blocking), establishing a lipid mediator → endogenous opioid peptide → pain relief signaling cascade.

Terashvili, Maia; Tseng, Leon F; Wu, Hsiang-En; Narayanan, Jayashree; Hart, Lucas M; Falck, John R; Pratt, Phillip F; Harder, David R · Animal Study

RPEP-01431 · 2008

GH Secretagogues Control the Shape and Size of Growth Hormone Pulses in Men

GHRP-2/GHRH combination precisely controlled GH secretory burst waveform (amplitude, duration, mass) in healthy men, with short-term hypogonadism reducing burst mass — demonstrating testosterone and secretagogues jointly regulate GH pulse quality.

Veldhuis, Johannes D; Keenan, Daniel M · Clinical Trial

RPEP-01433 · 2008

Predicting How Lactoferricin Binds Bacterial Membranes Using Computer Simulations

Binding free energy predictions for lactoferricin B-POPC membrane interaction using MD simulations correlated with experimental data, validating computational methods for predicting antimicrobial peptide-membrane interactions — rational design without extensive synthesis.

Vivcharuk, Victor; Tomberli, Bruno; Tolokh, Igor S; Gray, C G · In Vitro

RPEP-01435 · 2008

T-Cell Activation and Environment Control How Sensitive T-Cells Are to VIP Anti-Inflammatory Peptide

CD4 T-cell VPAC-1 receptor expression was regulated by TCR activation strength and cytokine milieu (IL-2, IL-7, IL-15), determining VIP immunomodulatory sensitivity — explaining context-dependent neuropeptide-immune regulation at the T-cell level.

Vomhof-DeKrey, Emilie E; Hermann, Rebecca J; Palmer, Megan F; Benton, Keith D; Sandy, Ashley R; Dorsam, Sheri T; Dorsam, Glenn Paul · In Vitro

RPEP-01436 · 2008

Self-Assembling Peptide Hydrogels Support 3D Liver Cell Culture for Drug Testing

Primary hepatocytes in RADA16 self-assembling peptide hydrogels maintained liver-specific functions (albumin secretion, urea synthesis, CYP450 activity) for extended culture — a functional 3D liver model for pharmaceutical drug metabolism and toxicity testing.

Wang, Sihong; Nagrath, Deepak; Chen, Pohun C; Berthiaume, François; Yarmush, Martin L · In Vitro