Biomaterial Database

Relationship between latency and period for 5-hydroxytryptamine-induced membrane responses in the Calliphora salivary gland. 1994

M J Berridge

Babraham Institute Laboratory of Molecular Signalling, Department of Zoology, Cambridge University, U.K.

Following stimulation with a calcium-mobilizing agonist there is often a distinct latency (L) preceding the onset of the first calcium spike. In the continued presence of the agonist, repetitive spikes appear separated by a variable period (P). The relationship between L and P has been investigated in an insect salivary gland responding to 5-hydroxytryptamine (5-HT). Both L and P were found to decrease as the concentration of 5-HT was increased over its physiological range of 1-10 nM. Lowering the concentration of external calcium from 1 x 10(-3) M to 1 x 10(-5) M increased both P and L. However, the effect on L was apparent only at low levels of 5-HT. Reducing the content of the internal stores by repeated stimulation in a calcium-free medium resulted in a progressive prolongation of L. On the other hand, the effect of L decreased when glands were stimulated repetitively in normal calcium-containing medium. All these results are consistent with a hypothesis that calcium plays a critical role in determining the kinetics of calcium release during both L and P. An important component seems to be the entry of external calcium, which sets the stage for calcium release by loading up the internal stores. As these stores fill up with calcium, the Ins(1,4,5)P3 receptors will initiate a calcium spike once they become sensitized to the ambient level of Ins(1,4,5)P3.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004175	Diptera	An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).	Flies, True,Flies,Dipteras,Fly,Fly, True,True Flies,True Fly
D005260	Female		Females
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
D012469	Salivary Glands	Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).	Gland, Salivary,Glands, Salivary,Salivary Gland
D012701	Serotonin	A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.	5-HT,5-Hydroxytryptamine,3-(2-Aminoethyl)-1H-indol-5-ol,Enteramine,Hippophaine,Hydroxytryptamine,5 Hydroxytryptamine
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor