ISSN:
1573-9686
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Technology
Notes:
Abstract To define the static gain and dynamic characteristics of the adrenal cortical response to its input hormone, ACTH, and the properties of elements that distribute, bind, and dispose of ACTH after it has entered the blood stream, we introduced graded pulses or graded, constant infusions of ACTH intravenously to unanesthetized dogs, previously prepared for the painless collection of adrenal vein blood. Our data demonstrate that the static gain of the cascaded elements under study is higher than previously described by others using anesthetized dogs. Furthermore, we found faster responses (a wider band-width), and a new response pattern, compared to prior work. The new output pattern, following pulse or step inputs, was defined by application of a linear mean-squared estimator designed as a feature extractor. The new output pattern is not predicted by current models of this system. The linear estimator was effective both as a filter and as an interpolator, and with it we were able to identify a cortisol secretory pattern that otherwise would have been lost in noise. The intra-dog variability was as high as the inter-dog variability in the system components under study. Ten physiological conclusions based on the use of the estimator are presented.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00000005
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