Age-dependent changes in 24-hour rhythms of catecholamine content and turnover in hypothalamus, corpus striatum and pituitary gland of rats injected with Freunds adjuvantReport as inadecuate




Age-dependent changes in 24-hour rhythms of catecholamine content and turnover in hypothalamus, corpus striatum and pituitary gland of rats injected with Freunds adjuvant - Download this document for free, or read online. Document in PDF available to download.

BMC Physiology

, 1:14

First Online: 28 November 2001Received: 07 August 2001Accepted: 28 November 2001

Abstract

BackgroundLittle information is available on the circadian sequela of an immune challenge in the brain of aged rats. To assess them, we studied 24-hour rhythms in hypothalamic and striatal norepinephrine NE content, hypothalamic and striatal dopamine DA turnover and hypophysial NE and DA content, in young 2 months and aged 18–20 months rats killed at 6 different time intervals, on day 18 after Freund-s adjuvant or adjuvant-s vehicle administration.

ResultsAging decreased anterior and medial hypothalamic NE content, medial and posterior hypothalamic DA turnover, and striatal NE concentration and DA turnover. Aging also decreased NE and DA content in pituitary neurointermediate lobe and augmented DA content in the anterior pituitary lobe. Immunization by Freund-s adjuvant injection caused: i reduction of DA turnover in anterior hypothalamus and corpus striatum; ii acrophase delay of medial hypothalamic DA turnover in old rats, and of striatal NE content in young rats; iii abolition of 24-h rhythm in NE and DA content of neurointermediate pituitary lobe, and in DA content of anterior lobe, of old rats.

ConclusionsThe decline in catecholamine neurotransmission with aging could contribute to the decrease of gonadotropin and increase of prolactin release reported in similar groups of rats. Some circadian responses to immunization, e.g. suppression of 24-h rhythms of neurointermediate lobe NE and DA and of anterior lobe DA were seen only in aged rats.

Electronic supplementary materialThe online version of this article doi:10.1186-1472-6793-1-14 contains supplementary material, which is available to authorized users.

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Author: Pilar Cano - Daniel P Cardinali - Fernando Chacon - Patricia O Castrillón - Carlos A Reyes Toso - Ana I Esquifino

Source: https://link.springer.com/



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