Published findings, in context.

Isolated human right atrial preparations: force of contraction and its pharmacological modulation

“Inotropic effects of retatrutide in isolated human atrial preparations.”

Neumann J, Ahlrep U, Hofmann B, Gergs U·Naunyn-Schmiedeberg's Archives of Pharmacology·2026·PMID 40613938 (opens PubMed in a new tab)·DOI 10.1007/s00210-025-04421-3 (opens the publisher record in a new tab)

Filed under GLP-3

Model

Right atrial preparations obtained during cardiac surgery from 29 patients (24 men and 5 women, aged 52–84); isometric force measurement under electrical stimulation in an organ bath

Sample size

29

Exposure

Retatrutide added to the isolated tissue at increasing concentrations, with and without a phosphodiesterase-3 inhibitor (cilostamide)

Comparator

Force of contraction before exposure; selective antagonists of the peptide's three receptors; propranolol, carbachol, stimulation of adenosine A1 receptors and ryanodine

Study by an academic group without affiliation to the developer. In isolated human right atrial preparations, retatrutide increased force of contraction in a concentration- and time-dependent manner; with the phosphodiesterase-3 inhibitor cilostamide present, the effect was larger and relaxation time shortened. The effect was reduced by selective antagonists of its three receptors and by carbachol, stimulation of adenosine A1 receptors and ryanodine, but not by propranolol; the authors interpret it as a cAMP-mediated action through those receptors rather than through β-adrenergic receptors. The sinus node and ventricular tissue were not examined.

Isolated rat aorta and cultured endothelial cells: vasomotor tone and Src–caveolin-1–eNOS signaling

“Modulatory effects of BPC 157 on vasomotor tone and the activation of Src-Caveolin-1-endothelial nitric oxide synthase pathway.”

Hsieh MJ, Lee CH, Chueh HY et al.·Scientific Reports·2020·PMID 33051481 (opens PubMed in a new tab)·DOI 10.1038/s41598-020-74022-y (opens the publisher record in a new tab)

Filed under BPC-157

Model

Ex vivo rat aortic rings with and without endothelium; 3D vascular smooth muscle cell model; cultured endothelial cells

Exposure

BPC-157 vs no-peptide preparations (ex vivo and in vitro)

Comparator

Preparations without peptide; L-NAME, hemoglobin, Src inhibitor

In isolated rat aorta, concentration-dependent vasodilation was observed that was attenuated in the absence of endothelium and inhibited by L-NAME or hemoglobin, indicating a nitric oxide-dependent mechanism. In endothelial cells, nitric oxide generation and phosphorylation of Src, caveolin-1 and eNOS increased and were abolished by a Src inhibitor, with less caveolin-1/eNOS association in co-immunoprecipitation assays. No direct relaxant effect on smooth muscle cells was seen in the 3D model.

Rat Achilles-derived fibroblasts: GHR gene and protein expression, proliferation and JAK2 signaling

Chang CH, Tsai WC, Hsu YH et al.·Molecules·2014·PMID 25415472 (opens PubMed in a new tab)Title on PubMed·DOI 10.3390/molecules191119066 (opens the publisher record in a new tab)

Filed under BPC-157

Model

Primary fibroblasts isolated from rat Achilles; cDNA microarray, quantitative PCR, Western blot

Exposure

BPC-157, with and without subsequent GHR-ligand stimulation, vs no-peptide culture

Comparator

Culture without peptide

Microarray analysis identified GHR among the most strongly induced genes in Achilles-derived fibroblasts exposed to the peptide; the concentration- and time-dependent increase was confirmed at the mRNA and protein levels. Subsequent stimulation of pre-exposed cells with the GHR ligand was associated with greater proliferation (MTT, PCNA) and JAK2 activation. In vitro observation whose in vivo relevance was not assessed.

Rat Achilles explants and Achilles-derived fibroblasts: outgrowth, survival, migration and FAK–paxillin signaling

Chang CH, Tsai WC, Lin MS et al.·Journal of Applied Physiology·2011·PMID 21030672 (opens PubMed in a new tab)Title on PubMed·DOI 10.1152/japplphysiol.00945.2010 (opens the publisher record in a new tab)

Filed under BPC-157

Model

Explant cultures of rat Achilles and primary rat Achilles-derived fibroblasts

Exposure

BPC-157 vs no-peptide culture

Comparator

Culture without peptide

In rat Achilles explants, cell outgrowth was faster; fibroblast proliferation (MTT) did not change, but survival under H2O2 stress, transwell migration and cell spreading increased in a concentration-dependent manner, with F-actin formation and higher FAK and paxillin phosphorylation and no change in total protein. The authors propose the FAK–paxillin pathway as a mechanistic hypothesis.