Detection of dermorphin-like immunoreactivity in immune tissues

Summary Site-directed antibodies against synthetic related dermorphin peptides have previously been produced and characterized. One of them, specifically recognizing the crucial ‘opioid message’ (the N-terminal part of the molecule Tyr-D-Ala-Phe-Gly), was used in the present study in order to detect and localize endogenous dermorphin-like molecules in immune tissues. Dermorphin-like peptides were found to be present in spleen and thymus of rat and mouse. The HPLC profile of the immunoreactive material showed a major peak at a retention time of 32±1 min. Purification of immune cells by panning procedures showed that both B and T cells contained this immunoreactive material. Biochemical characterization of the dermorphin-like immunoreactivity indicated that this material is a peptide resistant to aminopeptidase hydrolysis, suggesting the presence of a putative D-amino acid residue or a residue conferring resistance to a proteolytic process.     

Identification of hemorphins in a cathepsin D bovine hemoglobin hydrolysate by radioimmunoassay and photodiode array detections

Morphinomimetic peptides have been purified fromhemoglobin enzymatic hydrolysates and a significantamount of evidence has been accumulated indicatingthat the generation of these peptides (hemorphins)might occur in vivo. In order to investigatetheir putative physiological role and processing fromhemoglobin in vivo, two methods were developed:a specific radioimmunoassay and a UV spectracomparison analysis. These methods were applied to acathepsin D bovine hemoglobin hydrolysate and allowedthe detection of two hemorphin-7 peptides. Thisobservation supports the putative implication ofcathepsin D in the in vivo release ofhemorphins. Among the two methods used in this study,the immunological approach exhibits highersensitivity and represents a useful method toinvestigate the in vivo role and physiologicalprocessing of hemorphins.     

Chromatographic analysis of the enkephalin immunoreactivity in the nucleus locus coeruleus of the cat after local colchicine administration

Cell bodies immunoreactive for methionine- and leucine-enkephalin are found in the area of the locus coeruleus (dorsolateral pons) of the cat after injection of colchicine in the ascending projections of the nucleus. Using radioimmunoassay procedures, it is shown that colchicine induces a significant increase in methionine- and leucine-enkephalin-immunoreactive material in this area of the brain. High pressure liquid chromatography analysis demonstrated that the immunoreactive materials were authentic methionine- and leucine-enkephalin. The methionine- and leucine-enkephalin patterns were identical in the colchicine injected and non-injected sides of the dorsolateral pons. It is suggested that, in this area of the brain, colchicine (i) does not significantly modify the processing of proenkephalin to form the pentapeptides methionine- and leucine-enkephalin, and (ii) does not induce the appearance of new substances reactive to the enkephalin antisera employed.     

Detection of dermorphin-like immunoreactivity in immune tissues

Site-directed antibodies against synthetic relateddermorphin peptides have previously been produced andcharacterized. One of them, specifically recognizingthe crucial opioid message (the N-terminal part ofthe molecule Tyr-D-Ala-Phe-Gly), was used in the presentstudy in order to detect and localize endogenousdermorphin-like molecules in immune tissues.Dermorphin-like peptides were found to be present inspleen and thymus of rat and mouse. The HPLCprofile of the immunoreactive material showeda major peak at a retention time of 32±1 min.Purification of immune cells by panning proceduresshowed that both B and T cells contained thisimmunoreactive material. Biochemical characterizationof the dermorphin-like immunoreactivity indicated thatthis material is a peptide resistant toaminopeptidase hydrolysis, suggesting the presence ofa putative D-amino acid residue or a residueconferring resistance to a proteolytic process.     

Identification of hemorphins in a cathepsin D bovine hemoglobin hydrolysate by radioimmunoassay and photodiode array detections

Summary Morphinomimetic peptides have been purified from hemoglobin enzymatic hydrolysates and a significant amount of evidence has been accumulated indicating that the generation of these peptides (hemorphins) might occur in vivo. In order to investigate their putative physiological role and processing from hemoglobin in vivo, two methods were developed: a specific radioimmunoassay and a UV spectra comparison analysis. These methods were applied to a cathepsin D bovine hemoglobin hydrolysate and allowed the detection of two hemorphin-7 peptides. This observation supports the putative implication of cathepsin D in the in vivo release of hemorphins. Among the two methods used in this study, the immunological approach exhibits higher sensitivity and represents a useful method to investigate the in vivo role and physiological processing of hemorphins.