Eur J Endocrinol
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

DOI: 10.1530/eje.0.1340379
European Journal of Endocrinology, Vol 134, Issue 3, 379-385
Copyright © 1996 by European Society of Endocrinology
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Morrissey, S. E
Right arrow Articles by Laycock, J. F
Right arrow Search for Related Content
PubMed
Right arrow Articles by Morrissey, S. E
Right arrow Articles by Laycock, J. F

Influence of oestrous cycle on the pressor recovery following haemorrhage in anaesthetized Brattleboro rats

Sinead E Morrissey, Joanna Baden-Fuller, Nirodhini Murugananthan, Saffron A whitehead and John F Laycock

Morrissey SE, Baden-Fuller J. Murugananthan N, Whitehead SA, Laycock JF. Influence of oestrous cycle on the pressor recovery following haemorrhage in anaesthetized Brattleboro rats. Eur J Endocrinol 1996;134:379–85. ISSN 0804–4643

A sexual dimorphism in the pressor responsiveness to the neurohypophysial hormone vasopressin may be associated with a peripheral interaction between ovarian steroids and the neurohypophysial hormone. Indeed, the ovarian steroids may inhibit the vasopressin-dependent component of the pressor response to haemorrhage. The present study examined the recovery of the arterial blood pressure following a single large 2%v/w) haemorrhage in anaesthetized male Long Evans (LE) rats and females of the same strain during either pro-oestrous or di-oestrous phases of the reproductive cycle. In addition the same recovery process was examined in Brattleboro rats with diabetes insipidus (BDI) lacking circulating vasopressin. All BDI rats had an impaired blood pressure recovery following haemorrhage compared with male rats of the parent LE strain, and this was irrespective of sex or stage of the oestrous cycle. While the blood pressure recovery was more impaired in both groups of BDI female rats than in the males of the same strain during the first 20 min after haemorrhage (both comparisons p < 0.001: ANOVA), there was no difference between the recoveries of the female rats in pro-oestrus or di-oestrus. In contrast a significantly impaired blood pressure recovery was observed in female LE rats at pro-oestrus, when circulating ovarian steroid concentrations are raised, compared with male (p < 0.001; ANOVA) and di-oestrous (p < 0.02; ANOVA) rats of the same strain. Heart rate responses to haemorrhage showed strain differences, with LE rats having initial decreased heart rates followed by a recovery process, while the heart rate responses of BDI rats increased immediately. The novel use of the female Brattleboro rat in this study provides evidence for the existence of an important inhibitory interaction between ovarian steroids and vasopressin during the blood pressure recovery phase following haemorrhage, and indicates a possible direct influence of gonadal steroids on the recovery process.

JF Laycock, Department of Physiology, Charing Cross & Westminster Medical School, Fulham Palace Rd, London W6 8RF, UK






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 European Society of Endocrinology.