Metabolic rate maximum

Kinetic constants of pentachloroethane metabolism have been determined in male Fischer 344 rats exposed to the vapour phase at a concentration of 2895 mg/ni for 6 h and then placed in exhaled breath chambers. The maximum metabolic rate was... 

Figure 2.5. Metabolic scope for activity (defined as the difference between maximum metabolic rate and the SMR) and the metabolic scope for survival (defined as the difference between the SMR and maximally suppressed metabolic rates). Hummingbird estimates shown for normothermic conditions and for torpor metabolic rates (the latter gives the full biological scope for activity). Suppressed metabolic rates for the aquatic organisms assume temperatures of about 20°C (except for the pumpkinseed, where suppressed metabolism occurs during overwintering hibernation at about 4°C). (Modified from Hochachka (1990.)...

Figure 2.10. Relationship between fuels, pathways, and maximum metabolic rates. (Modified from Hochachka and Somero, 1984, and McGilvery, 1973.)...

Darveau et al. (2002, 2003) propose that the relationship between body mass and metabolic rate reflects the contribution of multiple factors - ATP-utilization processes in parallel, supply processes in series - that each have different power functions. This hierarchical layering results in an allometric cascade that has different scaling implications for different measures of metabolism. They contend that only a multiple-factor account, and not West s (or any) single-cause account, can explain the scaling difference between basal and maximum metabolic rate (Bishop, 1999). However, the mathematical formulation of their model has been severely criticized (Banavar etal., 2003 West etal., 2003), and in any case it does not provide an account of why individual processes scale as power functions of mass or why the causal cascade results in a whole-organism metabolism that approximates the 3/4 rule (Bokma, 2004 West et al., 2003 West and Brown, 2004). 

Parameter Tissue/blood partition (unitless) Diffusion limitation (1 h- kg- =) Maximum metabolic rate (pg kg ° ) Michaelis-Menten affinity (pg T ) other... 

Brain maximum metabolic rate AChE reactivation rate BuChE reactivation rate / AChE degradation rate ... 

For most species maximum metabolic rate is about 10 times basal [33, p. 212]. However, some very athletic animals have much higher ratios of maximal to basal rates pronghorn antelopes can achieve ratios of 65, and alligators can reach 40. A very informative discussion of diet, metabolic rates, and temperature control is provided in Chapter 14 of Reference 32. 

A number of parameters such as, e.g., renal clearance, basal oxygen consumption (metabolic rate), area under the curve (AUC), maximum metabolic velocity, or cardiac output correlate to the body weight to the power of 0.75 Further support for the power of 0.75 comes from a more... 

Nonetheless, there is considerable cause for concern about the use of psychotropic medication in preschool-age children during a period of continued rapid neural maturation (including synaptic remodeling and construction). The cortical synaptic density reaches its maximum at the age of 3 years and is substantially modified by the pruning process during the next 7 years (Huttenlocher, 1990). At the same time, the cerebral metabolic rate peaks between 3 and 4 years of... 

A correlation was also presented between life-span and (Cu,Zn)- plus (Mn)-SOD activities of two strains of Drosophila melanogaster. The short-living vestigial strain had an activity of 72% on the average of the wild strain With 2 rodent and 12 primate species there was a good correlation between the ratio of SOD activity to specific metabolic rate and the maximum life-span potential for the brain, heart, and liver... 

Most T-2 users reported an increase in metabolic rate and activity proportionate to dosages as listed. This supplement has been noted as exceptionally beneficial for individuals who have a slower metabolic rate naturally that results in above normal fat storage and poor post-training recovery at a dosage of 50 MG, 4 times daily. Others had found the higher listed dosages necessary for rapid fat loss at maximum rates. Most reported improved rate of recovery, improved lean mass to fat ratio, and often an increase in libido. (No Joke)... 

Once a chemical enters the body of an animal (based on the route of entry), the chemical is subjected to metabolism by a variety of mechanisms. The toxicity of many chemicals is dependent on the metabolic rate and pattern of the system. Many tissues are capable of metabolizing substances. However, the maximum activities have been found to occur in the liver, followed by the lung, the intestine, the skin, and the kidneys. The nature of the chemical interactions, biochemical interactions, and metabolic transformations help to determine the toxicity of the chemical. A number of authors have written reviews about the biotransformation of many substances.19,25 28... 

Fuel/Pathway Maximum Sustainable Metabolic Rate jimol ATP/g/min 100 ... 

---