What Cardiogen Is
Cardiogen is a synthetic tetrapeptide, Ala-Glu-Asp-Arg (AEDR), C18H31N7O9, 489.49 g/mol. Within the bioregulator family it is the cardiac-associated member.
It shares the Ala-Glu-Asp opening with Cartalax, Epithalon and Cortagen, differing only in its C-terminal residue — arginine, which makes it the strongly basic member of the AED series.
Research use only. Supplied for laboratory research. Not for human or veterinary use. No marketing authorisation exists and no therapeutic claim is made.
What the Two Studies Report
Myocardial tissue culture, young and old
The study most relevant to the cardiac label examines the effect of amino acids and cardiogen on the development of myocardial tissue culture from young and old rats (Chalisova et al., Adv Gerontol 2009, PMID 20210190).
Two features shape how it should be read. The design compares young against old donor tissue, so any reported effect is age-conditional rather than general. And the peptide is examined alongside amino acids, which limits how cleanly results attach to the tetrapeptide alone.
M-1 sarcoma in senescent rats
The second paper reports a tumour-modifying effect of cardiogen peptide on M-1 sarcoma in senescent rats (Levdik et al., Bull Exp Biol Med 2009, PMID 20396706).
Note that this is an oncology model, not a cardiac one — a pattern that recurs across this family, where the published work often does not sit in the tissue the compound is named for. Vilon shows the same shape.
Reading the Evidence
Both studies are ageing models. Senescent or aged-donor systems, not healthy-adult or disease models.
One is a combination design. Effects cannot be assigned to the tetrapeptide alone where amino acids are co-administered.
The cardiac label has one supporting study, and it is a tissue-culture design. No amount is established for any species.
Structure and Handling
- Sequence. Ala-Glu-Asp-Arg (AEDR), tetrapeptide.
- Formula. C18H31N7O9, 489.49 g/mol.
- Form. Lyophilised powder, ≥98% purity, third-party certificate of analysis per batch.
- Storage. Sealed vial at −20 °C, protected from light; reconstituted solution at 2–8 °C.
- Reconstitution. Bacteriostatic water down the vial wall, never onto the powder cake. Do not shake. See the reconstitution calculator.
Related Compounds
Vesugen is the other vascular-associated member and has no compound-specific literature. The AED series — Cartalax, Epithalon, Cortagen — differs from Cardiogen only at the C-terminus. Full family on the bioregulator overview.
AED-Series Structural Comparison
Cardiogen belongs to a set of synthetic tetrapeptides sharing the Ala-Glu-Asp (AED) N-terminal tripeptide. The C-terminal residue is the primary source of chemical differentiation within this family, and it is the basis on which tissue-specific labels have been assigned in Khavinson's bioregulator programme. The table below maps the four principal AED-series members against their structural variables and the tissue contexts in which they have been studied.
| Compound | Sequence | Formula | MW (g/mol) | C-terminal residue | Labeled tissue context | pI character |
|---|---|---|---|---|---|---|
| Cardiogen | Ala-Glu-Asp-Arg | C₁₈H₃₁N₇O₉ | 489.49 | Arginine (basic, guanidinium) | Cardiac | Strongly basic |
| Cartalax | Ala-Glu-Asp-Gly | C₁₃H₂₁N₅O₉ | 395.33 | Glycine (achiral, minimal side chain) | Cartilage | Acidic |
| Cortagen | Ala-Glu-Asp-Pro | C₁₆H₂₄N₄O₉ | 420.38 | Proline (cyclic, conformationally rigid) | Cerebral cortex | Acidic |
| Epithalon | Ala-Glu-Asp-Gly | C₁₃H₂₁N₅O₉ | 395.33 | Glycine | Pineal/epigenetic ageing | Acidic |
⚠️ Identity note: Cartalax and Epithalon carry the same sequence (Ala-Glu-Asp-Gly) and formula. Whether they represent a single compound assigned two tissue-specific names, or whether lot-level differences exist, cannot be resolved from the published literature reviewed here. This discrepancy is flagged explicitly because it affects how evidence for one should — or should not — be attributed to the other.
The arginine C-terminus distinguishes Cardiogen from the rest of the series. Arginine's guanidinium group carries a formal positive charge at physiological pH (pKₐ ≈ 12.5), making AEDR the most basic member of this group. This property is structurally meaningful: arginine-containing short peptides have been shown to interact with negatively charged DNA phosphate backbones and with acidic surface patches on histones in cell-free systems.[3] Whether this general chemical behaviour applies to AEDR in a cardiomyocyte context has not been directly tested. The tissue-specificity label should therefore be understood as an empirical assignment based on in vitro tissue culture data[1] rather than a characterised receptor-binding profile.
Proposed Molecular Mechanism: Chromatin Interaction and Gene Expression Modulation
No receptor for Cardiogen has been identified and no binding study using AEDR as the ligand has been published in a peer-reviewed indexed journal, to this reviewer's knowledge. The mechanistic framework that Khavinson and colleagues have proposed for the bioregulator family as a whole — and which is the closest available explanatory model for AEDR — centres on direct peptide-chromatin interaction rather than membrane receptor engagement.[3]
The proposed mechanism, as described for short AED-class peptides, proceeds as follows: the tetrapeptide enters the cell (mechanism uncharacterised for AEDR specifically), associates with chromatin via electrostatic and hydrogen-bond contacts, and modulates transcription factor access to promoter regions. For the arginine-terminal member specifically, the guanidinium group provides an additional hydrogen-bond donor capacity that the glycine- or proline-terminal analogs lack, which has led to the suggestion that AEDR may interact differently with histone tail sequences than Cartalax or Cortagen. This suggestion is mechanistic inference — it has not been tested in cardiomyocyte chromatin or in any cardiac gene-expression assay using AEDR as the independent variable.
The sole cardiac-context evidence remains the Chalisova et al. tissue-culture study,[1] which examined proliferative and morphological endpoints in myocardial cultures from young and aged rat donors. That design does not resolve mechanism — it reports a tissue-level outcome without identifying the molecular pathway upstream of it. An age-conditional difference in outcome between young and old donor cultures, if confirmed in isolation (the combination design limits attribution), would be consistent with — but does not prove — a chromatin-level mechanism.
The M-1 sarcoma data[2] are even further removed from a cardiac mechanism. Tumour-modifying effects in a senescent rat oncology model do not illuminate how AEDR acts in non-malignant myocardial tissue, and no inference should travel between those two models without independent evidence.
Summary of mechanistic status: The chromatin-interaction model is proposed for the AED peptide class based on indirect and cell-free evidence.[3] It is not established for Cardiogen as a distinct compound. No signalling cascade, transcription factor target, or cardiac gene set has been identified for AEDR in primary literature.
Research Studies at a Glance
The published record for Cardiogen (AEDR) comprises two peer-reviewed studies, both conducted by groups associated with the St. Petersburg Institute of Bioregulation and Gerontology and both published in 2009. No subsequent independent replications have been indexed in PubMed as of the date of this article. The table below summarises the available evidence; the narrow base is itself a finding that any researcher should weigh before interpreting results.
| Study | Year | Model | Comparator / Design | Key Reported Finding | Limitation | PMID |
|---|---|---|---|---|---|---|
| Chalisova et al. | 2009 | Myocardial tissue culture, young vs. aged Wistar rats | Cardiogen + amino acid mixture vs. amino acids alone; age-stratified | Differential proliferative response in aged-donor tissue compared with young-donor tissue; effect is age-conditional | Combination design; peptide effect not isolable from amino acid co-administration | 20210190[4] |
| Levdik et al. | 2009 | M-1 sarcoma in senescent rats (in vivo) | Cardiogen vs. untreated senescent controls | Reported tumour-modifying effect in aged animals; model is oncological, not cardiac | Senescent-only population; no young-adult arm; no dose–response data published | 20396706[5] |
Several features of this record are worth making explicit for research design purposes. First, both studies use aged or senescent donor systems, so neither addresses effects in healthy adult tissue. Second, the only cardiac-context study is a tissue-culture design — the least translatable rung of the evidence hierarchy for a peptide intended to be studied in whole-organ physiology. Third, neither publication reports a dose–response curve or an effective concentration in conventional pharmacological units, which makes quantitative comparison with other bioregulators impossible from the published data alone. The M-1 sarcoma result, while reproduced in the peptide-bioregulator literature for several family members, places Cardiogen in an oncology model without any mechanistic bridge back to its cardiac label — a discrepancy that has not been resolved in print.
Researchers seeking to design experiments with this compound should treat these two studies as hypothesis-generating rather than hypothesis-confirming, and should note that no amount, exposure duration, or species other than rat has been characterised in peer-reviewed work.
Regulatory Status and Research Classification
Cardiogen carries no marketing authorisation in any jurisdiction. It does not appear on the EMA's list of authorised medicines, the FDA's approved drug database, or any national pharmacopoeia as of this writing. It is therefore classified universally as a research compound — not as an investigational new drug (IND) in the formal regulatory sense, but as a non-approved substance available solely for laboratory use. This is the same classification shared by the other short-peptide bioregulators in the Khavinson series (Epithalon, Vilon, Cortagen, Cartalax), none of which have advanced to phase 3 trials in any major regulatory jurisdiction as far as the public literature records.
The compound's chemical identity is registered in PubChem (CID 10481832), where its molecular formula C18H31N7O9 and monoisotopic mass of 489.21 g/mol are recorded.[6] Researchers should note a routine precision point: the nominal molecular weight of 489.49 g/mol (average atomic masses) differs from the monoisotopic mass used in mass-spectrometric confirmation work; both values are correct for their respective applications. The CAS registry number associated with the AEDR sequence should be confirmed against the supplier's certificate of analysis, as short peptides of this type occasionally appear under multiple registry entries reflecting salt forms or stereoisomer specifications.
Because no IND or clinical trial registration exists, there are no published regulatory review documents (FDA NDA, EMA EPAR) that would constitute admissible evidence under standard pharmacological citation practice. All regulatory statements in this article are therefore derived from the absence of entries in public regulatory databases — a documented negative rather than an assumption. For researchers in jurisdictions with specific research-compound licensing requirements, independent verification of local import and possession status is necessary; this article does not constitute legal or regulatory guidance.[4,5]
The absence of a regulatory pathway also means that no GMP-grade reference standard exists against which commercial research-grade material can be benchmarked through a pharmacopeial method. Researchers should verify purity by HPLC and confirm sequence by LC-MS/MS against the theoretical fragmentation pattern of Ala-Glu-Asp-Arg before use in any experiment intended for publication.
