Endocrine Abstracts

Adrenomedullin and pro-adrenomedullin N terminal 20 peptide (PAMP) are multi-functional peptides that are cleaved from a precursor peptide named proadrenomedullin. It has been well documented that adrenomedullin has an effect on cell growth and differentiation in many cell types. However, the effects of PAMP on cell growth still remain to be elucidated.

Using the human endothelial cell line (HMEC-1) and human adrenocortical cell line (H295R), cells were plated, serum starved overnight and stimulated with a range of concentrations of human PAMP from 1pmol/l to 1umol/l. After three days, cells were trypsinised and counted with trypan blue to ensure cell viability.

PAMP caused an increase in cell numbers in a dose-dependent manner. The minimum effective concentration in H295R cells was 10pmol/l and 100pmol/l in the endothelial cell line. In both cell lines, the maximum effect was seen at 10nmol/l. PAMP was also seen to have an additive effect with adrenomedullin in both cell types.

To conclude, PAMP as well as adrenomedullin causes proliferation of both vascular and adrenocortical cells.