Gonadectomy Reverses The Sexually Diergic Patterns Of Circadian and Stress‐Induced Hypothalamic‐Pituitary‐Adrenal Axis Activity In Male and Female Rats

Journal of Neuroendocrinology - Tập 16 Số 6 - Trang 516-524 - 2004
Helen C. Atkinson1, Susan A. Wood1, Elizabeth MacGregor1, Stafford L. Lightman1, C.D. Ingram2, David S. Jessop1, M S Harbuz1
1LINE, Dorothy Hodgkin Building, University of Bristol, Bristol, Bristol, UK.
2School of Neurosciences and Psychiatry, University of Newcastle upon Tyne, UK

Tóm tắt

AbstractEnhanced corticosterone release by female compared to male rats under basal and stress conditions is well documented. The demonstration that gonadectomy enhances stress‐induced corticosterone secretion in male rats, but reduces such levels in female rats, suggests a causal association between gonadal steroids and corticosterone release. The present study examined the corticosterone profile of sham gonadectomized and gonadectomized female and male rats under basal and stress conditions. An automated sampling system collected blood from each freely moving, unanaesthetized rat every 10 min (i) over a 24‐h period; (ii) following noise stress; and (iii) following an immune‐mediated stress (lipopolysaccharide, LPS). Plasma was analysed for corticosterone content using radioimmunoassay. Castration resulted in a significant increase in basal corticosterone release compared to the sham‐castrated male rats. Pulsar analysis revealed a significant two‐fold increase in the number of corticosterone pulses over 24 h. Corticosterone increases in response to noise stress and to LPS injection were enhanced following castration. Conversely, ovariectomy resulted in a two‐fold reduction in the number of corticosterone pulses as well as the stress response compared to sham‐ovariectomized female rats. Arginine vasopressin (AVP), corticotrophin‐releasing hormone (CRH) and glucocorticoid receptor mRNAs in the paraventricular nucleus and pro‐opiomelanocortin (POMC) mRNA in the anterior pituitary were analysed post‐LPS administration by in situ hybridization. Significantly higher values were found for AVP, CRH and POMC mRNAs examined for sham females and castrated males compared to sham males and ovariectomized females. This study confirms previous reports concerning the influence of gonadal factors in regulating HPA axis activity and stress responsiveness. The present results extend these observations to the regulation of the dynamic pattern of corticosterone release under basal conditions and suggests that this alteration in pulsatility is important for the differences in stress responsiveness when comparing males and females.

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Tài liệu tham khảo

10.1210/endo.139.2.5721

Veldhuis JB, 1989, Amplitude modulation of a burst like mode of cortisol secretion subserves the circadian glucocorticoid rhythm, Am J Physiol, 257, E6

10.1677/joe.0.1290099

Harbuz MS, 1997, Steroid Hormones and the T‐Cell Cytokine Profile.

10.1210/endo-68-5-818

Critchlow V, 1963, Sex differences in resting pituitary‐adrenal function in the rat, Am J Physiol, 205, 807, 10.1152/ajplegacy.1963.205.5.807

10.1210/endo-105-3-812

10.1523/JNEUROSCI.16-05-01866.1996

10.1016/0031-9384(94)90018-3

Viau V, 1991, Individual differences in the hypothalamic‐pituitary‐adrenal response to stress: relationship to testosterone, Soc Neurosci Abstract, 17, 542

10.1210/endo.131.3.1324155

10.1210/endo-129-5-2503

Atkinson HC, 1997, Circadian variation in basal plasma corticosterone and adrenocorticotropin in the rat: sexual dimorphism and changes across the estrous cycle, Endocrinology, 9, 3842, 10.1210/endo.138.9.5395

10.1016/S0091-3057(99)00148-3

10.1530/eje.0.1310535

Patchev VK, 1995, Implications of estrogen dependent brain organisation for gender differences in hypothalamo‐pituitary‐adrenal regulation, FASEB, 9, 419, 10.1096/fasebj.9.5.7896013

Bingaman EW, 1994, Neuroendocrinology, 228

10.1523/JNEUROSCI.19-15-06684.1999

10.1016/0169-328X(90)90025-9

10.1159/000054474

10.1677/joe.0.1220705

10.1016/0304-3940(86)90463-5

Takahashi H, 1983, POMC probe, Nucl Acid Res, 11, 6647

10.1046/j.1365-2826.2000.00449.x

10.1016/0006-8993(91)91612-5

Merriam GR, 1982, Algorhythms for the study of episodic hormone secretion, Am J Physiol, 243, E310

10.1210/en.139.10.4044

Festing MFW, 2002, The Design of Animal Experiments

10.1111/j.1749-6632.1999.tb07621.x

10.1016/S0091-6773(75)90374-0

10.1006/hbeh.1994.1044

10.1046/j.1365-2826.2001.00715.x

10.1159/000126645

10.1159/000125197

10.1177/074873049300800403

10.1677/joe.0.1530159

10.1111/j.1365-2265.1987.tb00810.x

10.1016/0304-3940(87)90056-5

10.1210/en.130.5.2991

10.1093/rheumatology/34.12.1117

10.1093/rheumatology/39.7.764

10.1016/0031-9384(88)90149-7

10.1046/j.1365-2826.1997.00587.x

10.1523/JNEUROSCI.18-14-05529.1998

10.1016/S0166-4328(98)00132-6

Buckingham JC, 1997, Stress, Stress Hormones and the Immune System

10.1111/j.1469-7793.2003.00221.x

10.1677/joe.0.1560245

10.1073/pnas.090571897

10.1159/000125638

10.1046/j.1365-2826.2001.00653.x

10.1016/0361-9230(89)90150-0

10.1210/endo-122-3-945

10.1046/j.1365-2826.1996.04735.x

10.1006/mcne.1993.1023

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Journal of Neuroendocrinology

Tập 16 Số 6

516-524

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