It is known that the ion-transporting capacity and the permeability to water of amphibian skins vary greatly both between and within species. Furthermore, the extent to which different skins respond to hormonal stimulation of these parameters also shows considerable inter- and intra-specific variation. As a first step towards defining a possible morphological basis for this physiological hetero...

The mitogen-activated protein kinase (MAPK) signal transduction pathway activated by mechanical stress was investigated in the isolated perfused amphibian (Rana ridibunda) heart. High perfusion pressure induced the rapid (30 s) and prolonged (30 min) phosphorylation of a p43-extracellular regulated kinase, a response almost completely inhibited by 25 microM PD-98059. c-Jun NH2-terminal kinase (...

A tachykinin peptide was isolated from an extract of the intestine of the European green frog, Rana ridibunda, and its primary structure was established as: His-Lys-Leu-Asp-Ser-Phe-Ile-Gly-Leu-Met.CONH2. This sequence was confirmed by chemical synthesis and shows two amino acid substitutions (leucine for threonine at position 3 and isoleucine for valine at position 7) compared with neurokinin A...

Zoonotic Cryptosporidium spp., particularly C. meleagridis, C. canis, and C. felis, are enteric protozoa responsible for major public health concerns around the world. To determine the spread of this parasite in Thailand, we conducted molecular identification of Cryptosporidium spp. from animal samples around the country, by collecting and investigating the feces of seagulls (Chroicocephalus br...

ABSTRACT Despite the intensive study of endothelin (ET) in mammals, the primary structure and biological activity of the peptide is not known for any species of non-mammalian tetrapod. Extracts of the stomach and the liver of the European green frog Rana ridibunda contained ET-like immunoreactivity measured by RIA using an antiserum raised against human ET-1. The amino acid sequence of the pept...

The defensive skin secretions of many amphibians are a rich source of bradykinins and bradykinin-related peptides (BRPs). Members of this peptide group are also common components of reptile and arthropod venoms due to their multiple biological functions that include induction of pain, effects on many smooth muscle types, and lowering systemic blood pressure. While most BRPs are bradykinin recep...