Rapid stress-induced inhibition of plasma testosterone in free-ranging male rufous-winged sparrows, Peucaea carpalis: Characterization, time course, and recovery

Abstract

Article (refereed) -postprintDeviche, Pierre; Gao, Sisi; Davies, Scott; Sharp, Peter J.; Dawson, Alistair. 2012Rapid stress-induced inhibition of plasma testosterone in free-ranging male rufouswinged sparrows, Peucaea carpalis: characterization, time course, and recovery. Endocrinology, 177 (1). 1-8. 10.1016/j.ygcen.2012.02.022 Contact CEH NORA team at noraceh@ceh.ac.uk General and ComparativeThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. 1Rapid stress-induced inhibition of plasma testosterone in free- 25Chronic stress generally inhibits the activity of the reproductive system. Acute stress also is 26 often inhibitory, but the mechanism involved and its persistence of action once animals are no 27 longer exposed to the stressor are poorly understood. We investigated the effect of capture and 28 restraint stress on plasma testosterone (T), luteinizing hormone (LH), and corticosterone 29(CORT) in free-ranging male rufous-winged sparrows, Peucaea carpalis. Stress decreased 30 plasma T between 10 and 30 min after capture and restraint but did not influence plasma LH, 31the main hormone that controls T secretion, suggesting that stress did not decrease plasma T 32 by inhibiting LH secretion. The stress-induced decrease in plasma T was associated with 33 elevated plasma CORT, but there was no evidence that these effects were functionally related. 34Plasma stress-induced T was positively related to plasma initial T measured within 2 min of 35 capture. This relationship was, however, complex as plasma T decreased proportionally more in 36 response to stress in sparrows with high than low plasma initial T. The relative sensitivity to a 37 same stressor was, therefore, individually variable and this variation was related to initial plasma 38 T. Birds caught and restrained for 30 min, and then released on their breeding territory before 39 recapture up to 6 hours later, maintained depressed plasma T, indicating that the effect of acute 40 stress on this hormone persists after the stressor removal. These studies provide new 41 information on the effects of acute stress on plasma T in free-ranging birds. In particular, they decrease plasma T by impairing LH secretion or attenuating the testicular sensitivity to this 77 hormone [13]. Acute stress in birds typically increases plasma CORT in 5-10 min [44,33,69,13] 78 and in the rufous-winged sparrow, plasma T decreases by 30% -50% after capture and 89No study has, to our knowledge, investigated the time course of endocrine recovery from 90 mild acute stress in wild, free-ranging birds. The second objective of the present work was to 106during the study period were in breeding condition [36,12,57]. 108 Capture and blood sample collection 110Sparrows were captured in response to simulated territorial intrusion (STI: conspecific 111 song playback), while they were on their breeding territory and using a Japanese mist ...

Up to the challenge? Hormonal and behavioral responses of free-ranging male Cassin's Sparrows, Peucaea cassinii, to conspecific song playback

“…All birds were caught and observed between 0600 and 1600. A previous study on free-ranging breeding males of a conspecific species, the Rufous-winged Sparrow, Peucaea carpalis, found that plasma T does not change consistently during the course of the day (Deviche et al, 2012).…”

“…Mounting evidence indicates that plasma androgens can also rapidly and facultatively decrease, e.g., in response to acute stress (Deviche et al, 2010(Deviche et al, , 2012Lynn et al, 2010;Moore et al, 2002;Wingfield et al, 1982) .…”

“…As the above studies also show, the inhibitory effect of stress on plasma T was not associated with a decrease of plasma LH, suggesting that it did not result from impairment of pituitary gland function. The mechanism by which acute stress rapidly decreases plasma T in birds and the role of this decrease are poorly understood (Deviche et al, 2010(Deviche et al, , 2012. Nevertheless, these observations emphasize the fact that plasma T, besides being seasonally regulated, is susceptible to facultative modulation not only by stimulatory factors, but also by rapidly acting inhibitory 16 factors.…”

Steroids in house sparrows (Passer domesticus): Effects of POPs and male quality signalling

“…This was experimentally demonstrated by Veiga (1992) who suggested that the female-female aggression could be related to the avoidance of nest parasitism, or expelling a potential female in order to maintain its monogamous status. In addition, the fact that all birds were maintained in a barn for one week could have resulted in some variations of TS levels due to stress (Deviche et al, 2012). AN levels were low in both males and females (male mean = 0.092 ng/ml, female mean = 0.088 ng/ml) compared to levels reported in Japanese quail (male mean = 1.9 ng/ml, female mean = 2.4 ng/ml) (Ramenofsky, 1984), but did not differ substantially from AN levels reported for prelaying female blue-throats (Luscinia svecica), (Pärn et al, 2008).…”

Níveis plasmáticos de corticosterona, testosterona e imunocompetência em Bufonídeos

“…Additionally, house sparrows implanted with testosterone and held in short days showed no suppression of cell-mediated immune activity, indicating that testosterone is not obligatorily immunosuppressive year-round in this species . Furthermore, studies in a diversity of vertebrate species have shown that stressors typically suppress testosterone levels (T), sometimes quite rapidly (Greenberg and Wingfield, 1987;Deviche et al, 2010, Deviche et al, 2012Deviche et al, 2014). Reduction on T levels has been reported after induced acute stress in reptiles (reviewed in Tokarz and Summers, 2011), and after a restraint challenge and toe-clipping in toads (Narayan et al, 2011b;Narayan et al, 2012).…”