| RESEARCH PAPER
|Year : 1997 | Volume
| Issue : 2 | Page : 92-98
Pharmacological activities of some synthetic peptides related to dermorphin
KM Sivanandaiah, Babu VV Suresh, SC Shankaramma, M Lakshmana
Objectives: To investigate the relationship between the structure of dermorphins (DM) and their pharmacological properties, six analogues of [Hyp6] DM and [Pro6] DM were synthesised and their biological activities were studied.
Methods: The peptides were synthesised by the solid phase method using 9-fluorenylmethoxycarbonyl amino acid trichlorophenyl esters as coupling agents and Merrifield resin as solid support. The opioid agonist activity was studied using co-axially, electrically stimulated contraction of isolated guinea pig ileum (GPI, in vitro). Their analgesic activity was assessed in mice using Eddy's hot plate method and tail-flick method. The antidiarrhoeal activity was determined by the charcoal meal test in mice.
Results: In the GPI assay, the synthetic analogues possess agonistic activity that are less pronounced than morphine. Peptides I and II (substitution of ser at position 7 and Gly at position 4 in [Hyp6] DM series respectively) possessed considerable analgesic activity but are almost inactive in the GPI assay. Peptide Ill ( [ Pro6, Sar7] DM) possess only analgesic activity. In GPI assay, peptide IV was inactive. Peptide V and VI had equipotent analgesic and antidiarrhoeal activity.
Conclusion: Peptides with various structures can possess specificities that may prove useful in biolo ical applications. Among them [Sar4, Hyp6, Tyr7] DM, [Hyp6. Pro7] DM, [Pro6, Sar ] DM and [Phg3,Pro4 ] DM exhibited a high degree of selectivity in their activities.
K M Sivanandaiah
Source of Support: None, Conflict of Interest: None