Biomaterial Database

The molluscan cardioactive neuropeptide FMRFamide: subcellular localization in bivalve ganglia. 1981

G T Nagle

Ganglia of the mollusk Macrocallista nimbosa were pooled, homogenized, and subjected to differential centrifugation. The neuropeptide Phe-Met-Arg-Phe-NH2 (FMRFamide) was concentrated in the microsomal pellet. When the medium-speed supernatant was centrifuged in a discontinuous sucrose gradient, three separate peaks of activity were detected and identified as acetylcholine, 5-hydroxytryptamine, and FMRFamide. The relative concentration of FMRFamide in each fraction was determined by bioassay and by radioimmunoassay (RIA). Both determinations revealed a peak of peptide in the middle of the sucrose gradient. Electron micrographs of each of the gradient interfaces were analyzed. The interface containing the peak of biological FMRFamide activity was enriched in two- to fivefold in neurosecretory granules with a mean diameter of 104 nm and various electron densities. Morphologically similar vesicles were also seen in intact ganglia. These findings support the notion that FMRFamide is a neurosecretory product. But the physiological function of the peptide in bivalve ganglia remains unknown.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008974	Mollusca	A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.	Molluscs,Mollusks,Mollusc,Molluscas,Mollusk
D009490	Neurosecretory Systems	A system of NEURONS that has the specialized function to produce and secrete HORMONES, and that constitutes, in whole or in part, an ENDOCRINE SYSTEM or organ.	Neuroendocrine System,Neuroendocrine Systems,Neurosecretory System,System, Neuroendocrine,System, Neurosecretory,Systems, Neuroendocrine,Systems, Neurosecretory
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D002458	Cell Fractionation	Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.	Cell Fractionations,Fractionation, Cell,Fractionations, Cell
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D003594	Cytoplasmic Granules	Condensed areas of cellular material that may be bounded by a membrane.	Cytoplasmic Granule,Granule, Cytoplasmic,Granules, Cytoplasmic
D005724	Ganglia	Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia