Hair cortisol and dehydroepiandrosterone concentrations in naturally Taenia solium infected pigs in Tanzania

Marta Montillo,Helena A Ngowi,Ernatus M Mkupasi,Alberto Prandi,Maria V Johansen,Chiara Trevisan

doi:10.1016/j.ygcen.2017.03.007

Abstract

The aim of this study was to measure hair cortisol and dehydroepiandrosterone (DHEA) concentrations in naturally Taenia solium infected and non-infected control pigs and assess the effect of an environmental change on the aforementioned parameters.Three hair patches were obtained from 13 T. solium infected and 15 non-infected controls sows, respectively corresponding to 3 time points (prior to, at and approximately two weeks after arrival at the research facility). Cortisol and DHEA were extracted using methanol and analysed by radio immune assay.Mean hair cortisol concentrations were significantly lower (p<0.001) in T. solium infected (4.7±3.0pg/mg) compared to control pigs (9.0±3.7pg/mg) prior to arrival at the research facility, however no significant difference was observed between the two groups at arrival and after approximately two weeks. Similar patterns were also observed for DHEA concentrations (infected pigs 253.9±82.3pg/mg, control pigs 387.7±116.4pg/mg) (p<0.001).Results showed that lean animals had significantly higher cortisol concentrations in both groups, infected and controls pigs, while DHEA was not significantly different between lean and normal animals.Results of this study have shown that an environmental change could have an effect on pigs’ hormonal levels suggesting an undergoing adaptation process. After the pigs were kept under the same conditions, fed and watered ad libitum, no significant differences were observed between the groups, but a drop in DHEA concentrations was observed in all the pigs. Weight however had an effect on cortisol levels as lean animals had significantly higher cortisol concentrations in both groups, compared to normal pigs.

Highlights

Cortisol and dehydroepiandrosterone (DHEA) are steroid hormones, both synthesized from pregnenelone, the master steroid hormone, which is derived from cholesterol (Fallahsharoudi et al, 2015; Payne and Hales, 2004)
After the pigs were kept under the same conditions, fed and watered ad libitum, no significant differences were observed between the groups, but a drop in DHEA concentrations was observed in all the pigs
As the sensitivity of the diagnostic method is low, non-infected pigs were purchased in villages of Morogoro rural district, Morogoro region, Tanzania where the prevalence of porcine cysticercosis is known to be low as pigs are usually kept confined and fed with commercial feed and kitchen leftovers (Makundi, 2012)

Summary

Introduction

Cortisol and dehydroepiandrosterone (DHEA) are steroid hormones, both synthesized from pregnenelone, the master steroid hormone, which is derived from cholesterol (Fallahsharoudi et al, 2015; Payne and Hales, 2004). Cortisol is a glucocorticoid produced by the adrenal cortex in response to adrenocorticotropic hormone (ACTH) secretion. DHEA is the most abundant circulating steroid hormone and is produced in the adrenal glands, the gonads and the brain (Ganong, 2005). It is a precursor for the synthesis of anabolic and sexual steroids. Studies suggest that variations in DHEA levels are associated with chronic health disorders (Abbasi et al, 1998; Tagliaferro and Ronan, 2001) Depletion of this hormone has been associated in humans with development of chronic unhealthy conditions (Tagliaferro and Ronan, 2001), experimental evidence strongly suggests that DHEA is closely linked to health maintenance (Tagliaferro and Ronan, 2001).

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