Biomaterial Database

CRF-like effects of sauvagine and urotensin I on synaptosomal tyrosine hydroxylase activity of mouse striatum. 1990

P Onali, and M C Olianas

Department of Neurosciences, University of Cagliari, Italy.

In the present study we have investigated whether sauvagine (SVG) and urotensin I (UT), two peptides displaying sequence homology with corticotropin-releasing factor (CRF), could affect synaptosomal tyrosine hydroxylase (TH) activity of mouse striatum in a manner similar to CRF. The enzyme activity was assayed in supernatants obtained following sonication and centrifugation of homogenates preincubated with the peptides. SVG and UT produced a concentration-dependent increase of TH activity with a half-maximal effect obtained at 5 and 10 nM, respectively. SVG and UT were as effective as CRF with maximal stimulations corresponding to 52-58% increase of basal enzyme activity, whereas the rank order of potency was SVG greater than UT = CRF. Kinetic analysis of TH activity versus low concentrations of the pterin co-factor (0.05-0.4 mM) indicated that the stimulations elicited by CRF, SVG and UT were associated with an increase in the Vmax of the enzyme form with high affinity for the co-factor. The CRF receptor antagonist alpha-helical CRF9-41 inhibited the effects of all 3 peptides. Moreover, the combined addition of CRF with either SVG or UT did not produce additive effects on TH activity. The stimulatory effects of CRF, SVG and UT were dependent on the concentration of extracellular free Ca2+, being minimal in a Ca2(+)-free medium and maximal at about 0.5 mM extracellular free Ca2+. These results indicate that SVG and UT can mimic the effect of CRF on synaptosomal TH by acting on a common receptor site associated with a Ca2(+)-dependent mechanism.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D003342	Corpus Striatum	Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.	Lenticular Nucleus,Lentiform Nucleus,Lentiform Nuclei,Nucleus Lentiformis,Lentiformis, Nucleus,Nuclei, Lentiform,Nucleus, Lenticular,Nucleus, Lentiform,Striatum, Corpus
D003346	Corticotropin-Releasing Hormone	A peptide of about 41 amino acids that stimulates the release of ADRENOCORTICOTROPIC HORMONE. CRH is synthesized by neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, CRH stimulates the release of ACTH from the PITUITARY GLAND. CRH can also be synthesized in other tissues, such as PLACENTA; ADRENAL MEDULLA; and TESTIS.	ACTH-Releasing Hormone,CRF-41,Corticotropin-Releasing Factor,Corticotropin-Releasing Hormone-41,ACTH-Releasing Factor,CRF (ACTH),Corticoliberin,Corticotropin-Releasing Factor-41,ACTH Releasing Factor,ACTH Releasing Hormone,Corticotropin Releasing Factor,Corticotropin Releasing Factor 41,Corticotropin Releasing Hormone,Corticotropin Releasing Hormone 41
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP
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
D012689	Sequence Homology, Nucleic Acid	The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.	Base Sequence Homology,Homologous Sequences, Nucleic Acid,Homologs, Nucleic Acid Sequence,Homology, Base Sequence,Homology, Nucleic Acid Sequence,Nucleic Acid Sequence Homologs,Nucleic Acid Sequence Homology,Sequence Homology, Base,Base Sequence Homologies,Homologies, Base Sequence,Sequence Homologies, Base
D013574	Synaptosomes	Pinched-off nerve endings and their contents of vesicles and cytoplasm together with the attached subsynaptic area of the membrane of the post-synaptic cell. They are largely artificial structures produced by fractionation after selective centrifugation of nervous tissue homogenates.	Synaptosome
D014446	Tyrosine 3-Monooxygenase	An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.	Tyrosine Hydroxylase,3-Monooxygenase, Tyrosine,Hydroxylase, Tyrosine,Tyrosine 3 Monooxygenase