Bradykinin (BK) isolated from plasma of the African lungfish, Protopterus annectens, contains four amino acid substitutions compared with BK from mammals (Arg(1)-->Tyr, Pro(2)-->Gly, Pro(7)-->Ala, Phe(8)-->Pro). Bolus intra-arterial injections of synthetic lungfish BK (1-1000 pmol/kg body wt.) into unanaesthetised, juvenile lungfish (n=5) produced a dose-dependent increase in arterial blood pressure and pulse pressure. The maximum pressor response occurred 2-3 min after injection and persisted for up to 15 min. The threshold dose producing a significant (P<0.01) rise in pressure was 50 pmol/kg and the maximum increase, following injection of 300 pmol/kg, was 9.3 +/- 2.3 mmHg. Injection of the higher doses of lungfish BK produced a significant (P<0.05) increase in heart rate (2.8 +/- 0.8 beats/min at 100 pmol/kg). In contrast, bolus intra-arterial injections of mammalian BK, in doses up to 1000 pmol/kg, produced no significant cardiovascular effects in the lungfish. The data support the existence of a functioning kallikrein-kinin system in the lungfish and demonstrate that the ligand-binding properties of the receptor(s) mediating the cardiovascular actions of lungfish BK are appreciably different from mammalian B1 and B2 receptors.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s1095-6433(01)00486-x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Type 2 vomeronasal receptor expression in the olfactory organ of African lungfish, Protopterus annectens.
Cell Tissue Res
November 2024
Laboratory of Veterinary Anatomy, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate, 020-8550, Japan.
The olfactory organ of tetrapods, with few exceptions, comprises the main and accessory organs: olfactory epithelium (OE) and vomeronasal organ (VNO). Unlike tetrapods, teleost fish lack a VNO. However, lungfish, a type of sarcopterygian fish closely related to tetrapods, possesses a lamellar OE similar to the OE of teleosts and a recess epithelium (RecE) resembling the amphibian VNO.
View Article and Find Full Text PDFThe genomes of all lungfish inform on genome expansion and tetrapod evolution.
Nature
October 2024
Department of Biology, University of Konstanz, Konstanz, Germany.
Article Synopsis
- The genomes of lungfishes, particularly the recently sequenced African and South American species, provide insights into the evolutionary transition from fish to tetrapods during the Devonian period.
- The Lepidosiren genome is the largest animal genome sequenced to date, about 91 Gb, and features significant genome expansion due to active transposable elements, growing rapidly over the past 100 million years.
- The study finds that while lungfish chromosomes retain features of their ancient tetrapod ancestors, the loss of limb-like appendages in some species is likely linked to the deletion of specific enhancers associated with limb development.
The West African lungfish secretes a living cocoon during aestivation with uncertain antimicrobial function.
bioRxiv
July 2024
Department of Integrative Biology, University of California, Berkeley, CA 94720.
One of the most exceptional adaptations to extreme drought is found in the sister group to tetrapods, the lungfishes (Dipnoi), which can aestivate inside a mucus cocoon for multiple years at reduced metabolic rates with complete cessation of ingestion and excretion. However, the function of the cocoon tissue is not fully understood. Here we developed a new more natural laboratory protocol for inducing aestivation in the West African lungfish, and investigated the structure and function of the cocoon.
View Article and Find Full Text PDFslc26a12-A novel member of the slc26 family, is located in tandem with slc26a2 in coelacanths, amphibians, reptiles, and birds.
Physiol Rep
June 2024
School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.
Solute carrier family 26 (Slc26) is a family of anion exchangers with 11 members in mammals (named Slc26a1-a11). Here, we identified a novel member of the slc26 family, slc26a12, located in tandem with slc26a2 in the genomes of several vertebrate lineages. BLAST and synteny analyses of various jawed vertebrate genome databases revealed that slc26a12 is present in coelacanths, amphibians, reptiles, and birds but not in cartilaginous fishes, lungfish, mammals, or ray-finned fishes.
View Article and Find Full Text PDFA detailed 3D MRI brain atlas of the African lungfish Protopterus annectens.
Sci Rep
April 2024
Department of Cell Biology, Faculty of Biological Sciences, Complutense University, 28040, Madrid, Spain.
The study of the brain by magnetic resonance imaging (MRI) in evolutionary analyses is still in its incipient stage, however, it is particularly useful as it allows us to analyze detailed anatomical images and compare brains of rare or otherwise inaccessible species, evolutionarily contextualizing possible differences, while at the same time being non-invasive. A good example is the lungfishes, sarcopterygians that are the closest living relatives of tetrapods and thus have an interesting phylogenetic position in the evolutionary conquest of the terrestrial environment. In the present study, we have developed a three-dimensional representation of the brain of the lungfish Protopterus annectens together with a rostrocaudal anatomical atlas.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!