Gastrointestinal system research

One of the surprising findings of recent brain and central nervous system research is that chemical substances previously considered to be exclusive to ihe province of the brain have been found in organs outside the nervous system (e.g., somatostatin, neurotensin, and enkephalins have been found in the gut), and conversely, that other substances active in other organs, but not previously associated with the central nervous system, have been found in the latter (e.g.. gastrin, vasoactive intestinal polypeptide (VIP), and choiecystokinin. traditionally associated with the gastrointestinal tract, but now found in the central nervous system). 

Kinter LB (2003) Safety pharmacology of the renal and gastrointestinal systems. In Williams PD, Bass AS (eds) Safety pharmacology A practical guide. Therlmmune Research, Gaithersburg, MD, pp 99-116... 

Psychoactive plants have been used by humans for recreational, spiritual, and therapeutic purposes for millennia (6). It is evident from the African plants that have received the most attention, such as T. iboga and Catha edulis that research has been focused on those plants most commonly used for spiritual or recreational purposes. This is understandable as these plants are often more obvious because of their cultural importance and consequently more noticeable, in particular hallucinogens. The more subtle, often more therapeutically important plants, such as mild stimulants, sedatives, those used to treat convulsions and epilepsy have been sadly overlooked. The CNS-related mode of action of many plants may not immediately be obvious, for example nausea and vomiting are associated with the gastrointestinal system but is often treated via the CNS with scopolamine. The hunger-suppressant (anorectic) activities of South African succulent plants of the species Hoodia (7) are another example. 

The allocation of an active ingredient in a matrix that is able to protect it from the adverse conditions of the surroundings, as well as to modulate its release in the gastrointestinal system, on the skin or in other sites have been created hnge interest in researchers, in the industry and in the academy. In this context, the encapsniation technology by spray chilling has become promising. 

Stirred tank models have been widely used in pharmaceutical research. They form the basis of the compartmental models of traditional and physiological pharmacokinetics and have also been used to describe drug bioconversion in the liver [1,2], drug absorption from the gastrointestinal tract [3], and the production of recombinant proteins in continuous flow fermenters [4], In this book, a more detailed development of stirred tank models can be found in Chapter 3, in which pharmacokinetic models are discussed by Dr. James Gallo. The conceptual and mathematical simplicity of stirred tank models ensures their continued use in pharmacokinetics and in other systems of pharmaceutical interest in which spatially uniform concentrations exist or can be assumed. 

This chapter reports the progress made in the development of probiotic, prebiotic and other preventative treatments for gastrointestinal diseases, which have potential for use in organic and low input monogastric livestock production systems. Most of the results discussed focus on research with pigs, but most results should be transferable to other monogastric animals including poultry. 

Generally speaking, fentanyl acts on the central nervous system and the gastrointestinal tract. Because of this, most of the effects of the drug are physical. It also causes many of the same effects as heroin, including euphoria and drowsiness. However, some research shows that the effects of heroin are more euphoric, and fentanyl is more analgesic. 

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