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Gonadotropin Release Inhibitor
The hormone of gonadotropins secreted by the anterior hypophyse gland effects on the gonads and play a crucial role in the process of gonadal development and function in vertebrates. In birds and mammals, luteinizinghormone (LH) regulates sex steroid production as well as ovulation, whereas follicle stimulating hormone (FSH) promotes spermatogenesis and ovarian follicle maturation. Since the isolation of gonadotropin-releasing hormone (GnRH), a hypothalamic decapeptide, from mammalian brain in the early 1970s, several other GnRHs have been identified in the brains of other vertebrates. Based on extensive studies in vertebrates, it was generally believed that GnRH is the only hypothalamic regulator of the release of pituitary gonadotropins. Some neurochemicals A neurochemical is a small organic molecule or peptide that participates in neural activity. The science of neurochemistry studies the functions of neurochemicals. Prominent neurochemicals Neurotransmitters and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required for the correct development of animals, plants and fungi. Due to the broad definition of a hormone (as a signaling molecule that exerts its effects far from its site of production), numerous kinds of molecules can be classified as hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and brassinosteroid), amino acid derivatives (e.g. epinephrine and auxin), protein or peptides (e.g. insulin and CLE peptides), and gases (e.g. ethylene and nitric oxide). Hormones are used to communicate between organs and tissues. In vertebrates, hormones are responsible for regulating a variety of physiological processes and behavioral activities such as diges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated respon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Reproductive System
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Hormones
Peptide hormones or protein hormones are hormones whose molecules are peptide, or proteins, respectively. The latter have longer amino acid chain lengths than the former. These hormones have an effect on the endocrine system of animals, including humans. Most hormones can be classified as either amino acid–based hormones (amine, peptide, or protein) or steroid hormones. The former are water-soluble and act on the surface of target cells via second messengers; the latter, being lipid-soluble, move through the plasma membranes of target cells (both cytoplasmic and nuclear) to act within their nuclei. Like all peptides and proteins, peptide hormones and protein hormones are synthesized in cells from amino acids according to mRNA transcripts, which are synthesized from DNA templates inside the cell nucleus. Preprohormones, peptide hormone precursors, are then processed in several stages, typically in the endoplasmic reticulum, including removal of the N-terminal signal sequence an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormones Of The Hypothalamus-pituitary-gonad Axis
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required for the correct development of animals, plants and fungi. Due to the broad definition of a hormone (as a signaling molecule that exerts its effects far from its site of production), numerous kinds of molecules can be classified as hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and brassinosteroid), amino acid derivatives (e.g. epinephrine and auxin), protein or peptides (e.g. insulin and CLE peptides), and gases (e.g. ethylene and nitric oxide). Hormones are used to communicate between organs and tissues. In vertebrates, hormones are responsible for regulating a variety of physiological processes and behavioral activities such as digestion, met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonadotropin-inhibitory Hormone
Gonadotropin-inhibitory hormone (GnIH) is a RFamide-related peptide coded by the '' NPVF'' gene in mammals. Discovery GnIH was discovered in 2000. It is an RFamide peptide that significantly reduced luteinizing hormone release in Coturnix Japonica (Japanese quail). This peptide emerged as the first tropic hormone known to inhibit gonadotropin secretion in the hypothalamic-pituitary-gonadal axis of vertebrates. Subsequent research identified GnIH peptide homologs in variety of mammals, including humans. Structure GnIH is a neurohormone classified as an RFamide (RFa) or RFamide-related peptide (RFRP), coded by the NPVF gene in mammals. The complete amino acid sequence varies by species, but all RFa and RFRP peptides contain an arginine-phenylalanine-amine sequence at the C-terminal. This is seen in both Coturnix Japonica GnIH RFa (Ser-Ile-Lys-Pro-Ser-Ala-Tyr-Leu-Pro-Leu-Arg-Phe-NH2), and the human homolog, RFRP-3 (Val-Pro-Asp-Leu-Pro-Glu-Arg-Phe-NH2). Production GnIH neuron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuropeptide VF Precursor
Neuropeptide VF precursor, also known as pro-FMRFamide-related neuropeptide VF or RFamide-related peptide precursor, is a propeptide that in mammals is encoded by the ''NPVF'' (or ''RPFP'') gene. The ''NPVF'' gene, and thus the propeptide, are expressed in neurons in the mediobasal hypothalamus. The propeptide is cleaved to form three other peptides, which are: * Neuropeptide SF (NPSF) (RFRP-1) – agonist of the NPFF1 and NPFF2 receptors ( EC50 = 29 nM and 0.0011 nM, respectively) * RFRP-2 – does not bind to either of the NPFF receptors; no known biological activity * Neuropeptide VF (NPVF) (RFRP-3) – agonist of the NPFF1 receptor ( IC50 = 0.7 nM) NPSF and NPVF, originally referred to as the RFamide-related peptides RFRP-1 and RFRP-3, respectively, are the mammalian homologs of the avian neuropeptide ''gonadotropin-inhibitory hormone'' (''GnIH''). The mammalian ''NPVF'' and avian ''GnIH'' genes, along with their aforementioned peptide products, were discovered conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, rival," which is derived from ''anti-'' ("against") and ''agonizesthai'' ("to contend for a prize"). Types Heroes and villains The antagonist is commonly positioned against the protagonist and their world order. While most narratives will often portray the protagonist as a hero and the antagonist as a villain, like Harry Potter and Lord Voldemort in '' Harry Potter'', the antagonist does not always appear as the villain. In some narratives, like Light Yagami and L in '' Death Note'', the protagonist is a villain and the antagonist is an opposing hero. Antagonists are conventionally presented as making moral choices less savory than those of protagonists. This condition is often used by an author to create conflict within a story. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroids
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Hundreds of steroids are found in plants, animals and fungi. All steroids are manufactured in cells from the sterols lanosterol (opisthokonts) or cycloartenol (plants). Lanosterol and cycloartenol are derived from the cyclization of the triterpene squalene. The steroid core structure is typically composed of seventeen carbon atoms, bonded in four " fused" rings: three six-member cyclohexane rings (rings A, B and C in the first illustration) and one five-member cyclopentane ring (the D ring). Steroids vary by the functional groups attached to this four-ring core and by the oxidation state of the rings. Sterols are forms of steroids with a hydroxy group at position three and a skeleton derived from cholestane. '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurochemicals
A neurochemical is a small organic molecule or peptide that participates in neural activity. The science of neurochemistry studies the functions of neurochemicals. Prominent neurochemicals Neurotransmitters and neuromodulators *Glutamate is the most common neurotransmitter. Most neurons secrete with glutamate or GABA. Glutamate is excitatory, meaning that the release of glutamate by one cell usually causes adjacent cells to fire an action potential. (Note: Glutamate is chemically identical to the MSG commonly used to flavor food.) * GABA is an example of an inhibitory neurotransmitter. * Monoamine neurotransmitters: **Dopamine is a monoamine neurotransmitter. It plays a key role in the functioning of the limbic system, which is involved in emotional function and control. It also is involved in cognitive processes associated with movement, arousal, executive function, body temperature regulation, and pleasure and reward, and other processes. **Norepinephrine, also known as noradr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonadotropin-releasing Hormone
Gonadotropin-releasing hormone (GnRH) is a releasing hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. GnRH is a tropic peptide hormone synthesized and released from GnRH neurons within the hypothalamus. The peptide belongs to gonadotropin-releasing hormone family. It constitutes the initial step in the hypothalamic–pituitary–gonadal axis. Structure The identity of GnRH was clarified by the 1977 Nobel Laureates Roger Guillemin and Andrew V. Schally: pyroGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2 As is standard for peptide representation, the sequence is given from amino terminus to carboxyl terminus; also standard is omission of the designation of chirality, with assumption that all amino acids are in their L- form. The abbreviations are the standard abbreviations for the corresponding proteinogenic amino acids, except for ''pyroGlu'', which refers to pyroglutamic acid, a derivative of g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
