sauvagine and dermorphin

New data on tachykinins and bombesins are displayed and the present situation of research on the novel amphibian skin peptides sauvagine and dermorphin is illustrated. The potent stimulant effect of sauvagine on ACTH and beta-endorphin release has been confirmed both in vivo and on columns of isolated and dispersed rat pituitary cells, and similarly the potent inhibitory effect on PRL and GH release, both in the rat and man. Particular emphasis is laid on the occurrence of sauvagine-like immunoreactivity in fish urophysis and in amphibian nervous structures, including the retina. It is suggested that the long-searched corticotropin releasing factor and PRL release-inhibiting factor may be a sauvagine-like peptide. Dermorphin, in its turn, has been found to cause, by intracerebroventricular injection, not only analgesia and catalepsy, but also conspicuous EEG and behavioral changes in the rabbit and chick, as well as a sharp reduction in gastric emptying time and gastric acid output in the rat, together with marked stimulation of PRL release.

Topics: Adrenocorticotropic Hormone; Amino Acid Sequence; Amphibian Proteins; Analgesia; Animals; Behavior, Animal; beta-Endorphin; Bombesin; Brain; Digestive System; Endorphins; Gastric Acid; Gastric Emptying; Hemodynamics; Histocytochemistry; Humans; Muscle Contraction; Muscle, Smooth; Oligopeptides; Opioid Peptides; Peptide Hormones; Peptides; Pituitary Hormones, Anterior; Prolactin; Protein Conformation; Skin; Substance P; Tachykinins

The effects of bombesin, sauvagine, physalaemin and dermorphin on rat CNS were observed. These peptides were administered to non-epileptic and epileptic rats: SEEG and DEEG were recorded. On the normal electrical background activity of rat brain only physalaemin had no effect. All the other peptides gave rise to slow activity with different duration. In the epileptic rat only sauvagine showed no effect whilst physalaemin reduced the epileptic activity, bombesin seemed to strengthen the action of metrazol and dermorphin blocked it at the onset. These observations will undergo FFT (Fast Fourier Transform) analysis.

Topics: Amphibian Proteins; Analgesics, Opioid; Animals; Bombesin; Brain; Electroencephalography; Epilepsy; Oligopeptides; Opioid Peptides; Peptide Hormones; Peptides; Physalaemin; Rats; Rats, Inbred Strains; Tachykinins; Vasodilator Agents

Extracts prepared from dried or fresh skins of more than 200 American amphibian species were subjected to biological screening in order to determine occurrence and contents of peptides active on smooth muscle preparations, systemic blood pressure and, subordinately, external secretions, anterior pituitary and the central nervous system. The peptide families identified in skin extracts were as follows: caruleins (caerulein, phyllocaerulein), tachykinins (physalaemin, phyllomedusin), bombesins (phyllolitorin, [Leu8]phyllolitorin, rohdeilitorin), bradykinins (phyllokinin and others), sauvagine, dermorphins (dermorphin, [Hyp6]dermorphin), tryptophyllins (numerous peptides) and, finally, miscellaneous peptides. None of the above peptide families showed a widespread distribution, but all were restricted to particular amphibian genera or stocks. The hylid frogs of the Phyllomedusinae family occupy a unique position, as their skin displayed the greatest variety and abundance of active peptides ever found in any amphibian is destined to increase because numerous other peptide molecules await isolation, elucidation of structure and definition of possible biological activities.

Topics: Amphibian Proteins; Amphibians; Animals; Bombesin; Bradykinin; Ceruletide; Neuropeptides; Oligopeptides; Opioid Peptides; Peptide Hormones; Peptides; Skin; Species Specificity; Tachykinins

A tentative approach to the systematic distribution of active peptides in the anuran cutaneous tissue is presented. Eleven peptide groups have been so far detected in the frog skin. The occurrence of seven major groups in different Archaeo-, Meso-, and Neo-batrachian amphibian stocks is briefly discussed. Tachykinins and caeruleins have been isolated from some Mesobatrachian (Xenopus) and old Neobatrachian families, even of Gondwanian ancestry, such as leptodactylids, myobatrachids, pelodryadids and ranids. A more widespread systematic distribution is reported for bradykinins and bombesins, occurring in Archaeobatrachian and Neobatrachian frogs, represented by several primitive families both of Laurasian and Gondwanian origin: among them are liopelmatids, discoglossids, myobatrachids, pelodryadids, heleophrynids and ranids. The unique position of Neotropical phyllomedusid frogs, a peculiar hylid stock with ancestral leptodactylid myobatrachid affinities is emphasized. As many as seven major peptide groups are present in these specialized climbing anurans: tachykinins, caeruleins, bombesins, bradykinins, sauvagine, dermorphins, tryptophyllins. Phyllomedusid frogs appear to display the highest adaptive level yet reached in the peptide biochemical evolution of the amphibian skin.

Topics: Amphibian Proteins; Amphibians; Animals; Biological Evolution; Bombesin; Bradykinin; Ceruletide; Oligopeptides; Opioid Peptides; Peptide Hormones; Peptides; Skin Physiological Phenomena

The skin of the neotropical hylid frogs belonging to the subfamily. Phyllomedusinae is a formidable factory and store-house of a variety of active peptides belonging to seven distinct families: the caeruleins (represented by phyllocaerulein), the bradykinins (phyllokinin), the tachykinins (phyllomedusin), the bombesins (phyllolitorin, [Leu8]phyllolitorin, rohdei-litorin), sauvagine, the dermorphins (dermorphin, [Hyp6]dermorphin) and finally the tryptophyllins (a set of 8-11 members). Another linear peptide and three diketopiperazines should be added to the list. The biochemical and pharmacological positions of the Phyllomedusa peptides within their families is briefly discussed, dwelling upon some recent and controversial data.

Topics: Amino Acid Sequence; Amphibian Proteins; Animals; Anura; Bombesin; Bradykinin; Ceruletide; Nerve Tissue Proteins; Neuropeptides; Oligopeptides; Opioid Peptides; Peptide Hormones; Peptides; Skin Physiological Phenomena; Tachykinins

The effect of dermorphin and sauvagine, two new peptides originally isolated from amphibian skin, on the release of gonadotropins and prolactin was studied "in vivo" and "in vitro." The intraventricular administration of dermorphin to castrated male rats induces a significant decrease in serum LH, but not FSH, levels. Subcutaneous, as well as intraventricular, injections of dermorphin to normal male rats induce a statistically significant increase in serum prolactin levels, which is counteracted by naloxone. In the isolated and dispersed rat pituitary cell preparation, the addition of dermorphin to the media does not induce any alteration in prolactin output. Intraventricular administrations of sauvagine are ineffective in influencing the secretion of both LH and FSH. This peptide is also unable to modify it when tested "in vitro". On the contrary, subcutaneous injections of sauvagine to either normal male or lactating rats decrease serum prolactin levels. This prolactin inhibitory effect is also present "in vitro." These results suggest that dermorphin and sauvagine modulate the secretory activity of the anterior pituitary gland. However, the mechanism of control is different: dermorphin needs the mediation of brain structures, while sauvagine acts directly at the pituitary level.

Topics: Amphibian Proteins; Animals; Dopamine; Follicle Stimulating Hormone; Injections, Intraventricular; Luteinizing Hormone; Male; Naloxone; Oligopeptides; Opioid Peptides; Orchiectomy; Peptide Hormones; Peptides; Pituitary Gland; Prolactin; Rats

Histochemistry has been the springboard for the identification in molluscan tissues (hypobranchial body and salivary glands) and amphibian skin of a number of biogenic amines, choline esters and active peptides. Among the biogenic amines 5-HT and related indolealkylamines, octopamine, tyramine and several histamines are to be listed; among the choline esters murexine, dihydromurexine, senecioylcholine and acryloylcholine; among the peptides an array of compounds belonging to at least ten different peptide families. 5-HT, octopamine, tyramine and histamine are present, together with representatives of some peptide families in the posterior salivary glands of octopods, the hypobranchial body of prosobranchiate molluscs and the amphibian skin. This points to the possible occurrence in the above structures of cells belonging to the Pearse's APUD series, intended in its broadest sense. Immunocytochemical studies and even ultrastructural studies on amine and peptide storing cells in molluscan tissues and amphibian skin are virtually lacking. This is certainly a gap that deserves to be filled, considering that these studies may help in elucidating problems of general relevance in invertebrates and vertebrates.

Topics: Amphibian Proteins; Amphibians; Animals; Biogenic Amines; Chemical Phenomena; Chemistry; Gills; Histocytochemistry; Octopodiformes; Oligopeptides; Opioid Peptides; Peptide Hormones; Peptides; Salivary Glands; Skin