Unilateral or bilateral vagotomy performed on prepubertal rats at puberty onset of female rat deregulates ovarian function

Abstract

Background Injecting a neurotoxin virus into ovary of adult rats has provided morphologic evidence of a multisynaptic neural pathway between ovary and central nervous system (CNS). Vagus nerve is one of the pathways used by CNS to send and receive information to and from the ovary. Methods The present study analyzed whether or not vagal innervation of ovaries in prepubertal rats modulated, in a stimulatory fashion, functions of the ovary and whether the modulating function of these nerves was asymmetric. Results Animals vagotomized at 24 and 28 days of age showed delay in age of onset of puberty. Unilateral or bilateral vagotomy performed at 24 days of age did not modify ovulation rates or number of ova shed. In turn, bilateral vagotomy performed at 28 days of age resulted in a significant increase in number of ova shed by ovulating animals. Unilateral and bilateral vagotomy performed on day 24 or 28 resulted in a decrease in estradiol serum levels. Unilateral vagotomy performed on 24-day-old rats did not modify progesterone levels, while bilateral vagotomy on the same age group resulted in a significant increase of progesterone levels. In turn, unilateral and bilateral vagotomy performed on rats aged 28 days resulted in lower progesterone levels. Conclusions Present results confirmed results of previous studies, indicating that interrupting ovarian innervation had an effect on regulation of ovarian functions by CNS and that these effects varied according to age at which denervation was performed.