And peripheral physiology

Hasenfratz, M., and Battig, K., Action profiles of smoking and caffeine Stroop effect, EEG, and peripheral physiology. Pharmacology, -Biochemistry-and-Behavior 42(1), 155-161, 1992. 

Serotonin mediates many central and peripheral physiological functions, including contraction of smooth muscle, vasoconstriction, food intake, sleep, pain perception, and memory, a consequence of it acting on several distinct receptor types. Although 5-HT may be metabolized by monoamine oxidase, platelets and neurons possess a high-affinity mechanism for reuptake of 5-HT. This mechanism may be inhibited by the widely prescribed antidepressant drugs termed selective serotonin re-uptake inhibitors (SSRl), e.g. fluoxetine (Prozac ), thereby increasing levels of 5-HT in the central nervous system. 

Chronic idiopathic pain syndrome is a common, disabling, and costly condition. It is believed to be of psychological origin but may involve both cerebral and peripheral physiologic mechanisms. Because it is often associated with depression, psychotropic drugs, notably the tricyclic antidepressants, may be required. 

CCK is found in the digestive tract and the central and peripheral nervous systems. In the brain, CCK coexists with DA. In the peripheral nervous system, the two principal physiological actions of CCK are stimulation of gaU. bladder contraction and pancreatic enzyme secretion. CCK also stimulates glucose and amino acid transport, protein and DNA synthesis, and pancreatic hormone secretion. In the CNS, CCK induces hypothermia, analgesia, hyperglycemia, stimulation of pituitary hormone release, and a decrease in exploratory behavior. The CCK family of neuropeptides has been impHcated in anxiety and panic disorders, psychoses, satiety, and gastric acid and pancreatic enzyme secretions. 

There is a second type of cholinesterase called butyrylcholinesterase, pseudocholinesterase, or cholinesterase. This enzyme is present in some nonneural cells in the central and peripheral nervous systems as well as in plasma and serum, the liver, and other organs. Its physiologic function is not known, but is hypothesized to be the hydrolysis of esters ingested from plants (Lefkowitz et al. 1996). Plasma cholinesterases are also inhibited by organophosphate compounds through irreversible binding this binding can act as a detoxification mechanism as it affords some protection to acetylcholinesterase in the nervous system (Parkinson 1996 Taylor 1996). 

To characterize the responses to PbTx-2, five dose rates (0, 12.5, 25, 50, and 100 ig/kg/hr in 2 ml saline) were infused into the jugular catheters of rats (four per group). Heart rates, systolic and diastolic arterial blood pressures, pulse pressures, respiratory rates, core and peripheral body temperatures, lead VI0 ECCjs, and arterial blood gases were monitored. Clinical signs and behaviors were recorded by video camera. After infusion, animals were monitored for 6 hr, by which time most had either died or recovered to near baseline physiological levels. 

The endogenous opioids are another family of peptides involved in different physiological processes including pain regulation, respiratory control, stress responses, appetite, thermoregulation, and humoral and cellular immune function (Bodnar RJ., 2008). Opioids act through their receptors, which are also members of the GPCR family, and are expressed in the central and peripheral nervous system as well as on cells of the immune system (Henriksen and Willoch 2008 Hauser... 

Since metaphit appears to specifically acylate PCP receptors, metaphit is a useful tool with which to study the physiological role of PCP receptors. When metaphit was administered ICV prior to IP administration of PCP, metaphit antagonized the ability of PCP to induce stereotyped behavior, but not its ability to induce ataxia. Thus, it appears that ataxia is mediated by both central and peripheral mechanisms. It is unlikely that the peripheral effect of PCP in induction of ataxia is mediated by PCP receptors as 20 mg/kg of metaphit administered IV only antagonized PCP -induced stereotyped behavior when PCP was also administered peripherally. 

Brindley, G. S. and E. N. Willmer (1952). The reflexion of light from the macular and peripheral fundus oculi in man. Journal of Physiology 116 350-356. 

There are important exceptions to the rule that the physiological effects of cAMP in mammals are achieved via the activation of protein kinase A. The most prominent is a class of ion channels, referred to as HCN (hyperpolarization cyclic nucleotide gated) channels, that directly bind, and are thereby gated by, cAMP. Several forms of HCN channel are widely expressed in brain and peripheral tissues and have been implicated in the regulation of many facets of cell function. 

Since OPC block ChE selectively in every cholinergic structure (bland N-cholinoreceptive systems), practically all physiological systems and organs can be involved in a pathological process. At that, changes in activity of the central and peripheral nervous systems as well as the resulting impairments in respiratory and cardiac activities have a critical influence on an outcome of the poisoning. 

Histopathological examination of tissues representative of the nervous system, including the brain, spinal cord, and peripheral nervous system Quantitative observations and manipulative test to detect neurological, behavioral, and physiological dysfuntions. These may include general appearance body posture... 

Physiologically, in both normal and hypertensive individuals, blood pressure is maintained by moment-to-moment regulation of cardiac output and peripheral vascular resistance, exerted at three anatomic sites (Figure 11-1) arterioles, postcapillary venules (capacitance vessels), and heart. A fourth anatomic control site, the kidney, contributes to maintenance of blood pressure by regulating the volume of intravascular fluid. Baroreflexes, mediated by autonomic nerves, act in combination with humoral mechanisms, including the renin-angiotensin-aldosterone system, to coordinate function at these four control sites and to maintain normal blood pressure. Finally, local release of vasoactive substances from vascular endothelium may also be involved in the regulation of vascular resistance. For example, endothelin-1 (see Chapter 17) constricts and nitric oxide (see Chapter 19) dilates blood vessels. 

The physiologic mechanism of cough is complex, and little is known about the specific mechanism of action of the opioid antitussive drugs. It appears likely that both central and peripheral effects play a role. 

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