ISSN:
1432-2013
Keywords:
Aldosterone plasma concentration
;
Corticosterone plasma concentration
;
Anaesthesia
;
Barbiturates
;
Abdominal surgery
;
Large intestine
;
Transepithelial potential difference
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The transepithelial voltage (Ψ ms) of rat rectum in vivo increases for several hours in experiments under general anaesthesia. So far this was attributed by indirect evidence to increasing aldosterone plasma levels during the course of the experiment. We performed direct measurements of aldosterone and corticosterone plasma concentrations during intestinal perfusion experiments on barbiturate anaesthetized rats. Experiments were terminated for blood sampling at 10, 75, 300, 400, 800, or 1,800 min, respectively. (i) After 75 min of anaesthesia, surgical preparation was finished and plasma levels of aldosterone and of corticosterone were found increased by the factors 5 and 3, respectively, as compared to conscious controls. (ii) During the following 12 h, aldosterone further increased to levels 10 times as high as those of controls. In contrast, during the same period corticosterone slowly decreased but still remained elevated as compared to controls. (iii) The increase of both hormones was attenuated when abdominal surgery was omitted. (iv) The use of pentobarbital (Nembutal) instead of thiobarbital (Inactin) did not influence the adrenal response. (v) In adrenalectomized rats a continous substitution with 65 ng·h−1·kg−1 BWT aldosterone resulted in plasma levels as high as in conscious intact animals. (vi) RectalΨ ms started to move to higher lumen-negative values with a time delay of 1–1 1/2 h as compared with the increase of hormone levels.Ψ ms then stayed elevated until to the end of the experiments. We conclude that in vivo experiments of several hours duration in thio- or pentobarbital anaesthetized rats take place under conditions of aldosterone and corticosterone plasma levels which are high as compared to those of conscious unstressed animals. The different time course of aldosterone and corticosterone plasma levels after the end of surgery would be in accord with a stimulatory effect of anaesthesia on both renin and ACTH, plus an additional stimulatory effect of abdominal surgery on ACTH alone.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00652747
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