Claviceps purpurea (Ergot):

Ergot (Claviceps purpurea), best known as a disease of rye and some other grasses, is probably the most widely cultivated fungus and has now become an important field crop. The main reason for its importance is the presence of ergot alkaloids, extensively used in medicine. Currently, ergot alkaloids cover a large field of therapeutic uses as drugs of high potency in the treatment of uterine atonia, postpartum bleeding, migraine, orthostatic circulatory disturbances, senile cerebral insufficiency, hypertension, hyperprolactinemia, acromegaly, and parkinsonism. Recently, new therapeutic uses have emerged, such as, e.g., against schizophrenia, applications based on newly discovered antibacterial and cytostatic effects, immunomodulatory and hypolipemic activity. Of the naturally occurring ergot alkaloids only two are used in the therapy: ergotamine and ergometrine. The rest of the therapeutically important ergot compounds are semisynthetic compounds. Ergot alkaloids are traditionally obtained by extraction of ergot sclerotia artificially cultivated on cereals. The parasitic cultures are not able to produce all alkaloids, e.g., clavine, necessary for most semisynthetic drugs. Crop fluctuations and market demand have Read more […]

DOPAMINE RECEPTOR AGONISTS

DOPAMINE RECEPTOR AGONISTS act to stimulate dopamine receptors, and these have a major neurotransmitter role in the CNS. Dopamine is also a precursor in the formation of the catecholamine monoamine neurotransmitter noradrenaline and the hormone adrenaline. The distribution of dopamine in the brain is very non-uniform. There is some in the limbic system, and a large proportion is found in the corpus striatum — a part of the extrapyramidal motor system which is concerned with the coordination of movement. Dopamine-containing nerves are found in three main pathways in the brain. The nigrostriatal pathway contains about 75% Of the dopamine in the brain, and the cell bodies lie in the substantia nigra and the nerves terminate in the corpus striatum. The second important pathway is the mesolimbic pathway, the cell bodies of which lie in the mid-brain and project to parts of the limbic system, particularly the nucleus accumbens. The third, the tubero-infundibular system, consists of short neurons that run from the arcuate nucleus of the hypothalamus to the median eminence and the pituitary gland, the secretions of which they regulate. With respect to disturbances of dopamine neurotransmitter function, the first-mentioned Read more […]