Comparison of the effects of oestrogen deficiency and old age on primary bladder afferent activity and voiding behaviour in the ageing female rat
Faculty of Medicine and Health Sciences
Publication type
Oxford ,
Human medicine
Source (journal)
BJU international / British Association of Urological Surgeons. - Oxford, 1999, currens
108(2011) :2b , p. E10-E16
Target language
English (eng)
Full text (Publishers DOI)
University of Antwerp
The effects of oestrogen on lower urinary tract structure and function, and on the autonomic nervous control of the region, have been examined in animal studies, often with conflicting results. To determine if a decrease in oestrogen levels increases activity in bladder afferent nerves, we investigated the effects of oestrogen loss on afferent nerve activity in rats subjected to ovariectomy. Comparisons were made with findings in ageing female rats. In conclusion, this study suggests that oestrogen deficiency caused by ovariectomy does not increase bladder afferent nerve activity in the rat. Even if it may affect storage function in the rat, it seems unlikely that oestrogen deficiency per se is the main driver of the increase in afferent activity and voiding frequency that is observed in ageing female rats. It has also been suggested that, although the prevalence of urinary incontinence increases with age, the increase may not be related directly to oestrogen deficiency in the postmenopausal female. OBJECTIVE To determine if a decrease in oestrogen (E) levels increases activity in bladder afferent nerves, by investigating the effects of E loss on afferent nerve activity in ovariectomized (OVX) rats, and making comparisons with findings in ageing female rats. MATERIALS AND METHODS Female Sprague-Dawley rats were divided into four groups: ageing; OVX+ E; OVX+ vehicle (V); and sham-operated (SHAM) + V. The E (250 µg/kg) or V (cottonseed oil) was injected s.c. once a week for 8 weeks. Frequencyvolume recordings were performed with the rats in metabolic cages, and single Aδ- or C-fibre activities from the bladder were measured. After measurements, the blood serum was collected and the estradiol (E2) level was measured. RESULTS The C-fibre activity of OVX + V rats was significantly lower than in the other groups. Aδ-fibre activity was unchanged. Despite low E2 levels, ageing rats showed high afferent activity and voiding frequency. CONCLUSION Although a low E level may affect storage function, it is unlikely that it is the main cause of the high afferent activity and voiding frequency observed in the ageing female rat.