Suppression of oocyte release in rats by local administration of the noradrenergic neurotoxin DSP4

in Reproduction
Authors:
J. M. Goldman
Search for other papers by J. M. Goldman in
Current site
Google Scholar
PubMed
Close
,
T. E. Stoker
Search for other papers by T. E. Stoker in
Current site
Google Scholar
PubMed
Close
,
R. L. Cooper
Search for other papers by R. L. Cooper in
Current site
Google Scholar
PubMed
Close
,
W. K. McElroy
Search for other papers by W. K. McElroy in
Current site
Google Scholar
PubMed
Close
, and
M. B. Parrish
Search for other papers by M. B. Parrish in
Current site
Google Scholar
PubMed
Close
Free access

Sign up for journal news

The presence of noradrenergic neuronal innervation in the ovaries and cyclic alterations in ovarian noradrenaline suggest a role for such innervation in oocyte release. The current experiments evaluated the relationship between ovulation and alterations in ovarian concentrations of noradrenaline induced by unilateral, intrabursal administration of the specific noradrenergic neurotoxin DSP4. Intrabursal injections of DSP4 (0–10 μmoles per ovary) given at 19:00 h at pro-oestrus induced a prompt, dose-related reduction in ovarian noradrenaline on the injected and non-injected sides. Although this result suggests that injected material was reaching the contralateral ovary, ovulation was suppressed only on the injected side. This suppression was persistent, and lasted through at least the next two cycles following either unilateral or bilateral treatment. The reductions in noradrenaline could be mostly, if not entirely, attenuated by prior administration of desipramine which blocks re-uptake of noradrenaline, while the ipsilateral ovulatory effects remained unchanged. Although it has been reported that DSP4 binds the opiate receptor, intrabursal co-administration of the antagonist naloxone was ineffective in altering ovulatory suppression. These results suggest that while decreases in ovarian noradrenaline in response to local exposure to a noradrenergic neurotoxin may accompany a reduction in oocyte release or a block in ovulation, the anti-ovulatory effect of DSP4 is independent of the changes in noradrenaline concentrations and may be due to some other ovarian response.

 

  • Collapse
  • Expand