Cutting the suspensory ligament reduced the ovarian content of norepinephrine (NE) to less than half that of controls and only a few blood vessels had perivascular fibers and an occasional nerve remained in the interstitial gland. Cutting the ovarian plexus had a less drastic, but similar effect on the ovarian content of NE and on the pattern of ovarian adrenergic nerves. Cutting both the suspensory ligament and ovarian plexus eliminated visualization of ovarian adrenergic nerves, but some ovarian NE was still measurable. Fluorescence and electron microscopic studies of the suspensory ligament revealed a large adrenergic nerve embedded in smooth muscle of the ligament. The nerve was also acetylcholinesterase-positive. Cutting the celiac plexus or incising a small nerve lateral to the plexus and medial to the origin of the suspensory ligament, had the same effect on the ovarian adrenergic nerves as cutting the suspensory ligament. It is concluded that the extrinsic adrenergic nerves to the rat ovary reach the organ by two routes: one via the nerve in the suspensory ligament (superior ovarian nerve), and one via the traditionally described ovarian plexus along the ovarian artery.

Hemiovariectomized rats were randomly assigned to 1 of 5 groups: controls, 6-hydroxydopamine (6-HD)-treated, abdominal vagotomy, 6-HD-treated plus abdominal vagotomy and pelvic parasympathectomy. 15 days later all animals were sacrificed and the amount of compensatory ovarian hypertrophy (COH) was calculated. Vagotomy and vagotomy plus 6-HD treatment interrupted estrous cycles and significantly decreased COH. Vagotomized rats with both ovaries intact had disrupted estrous cycles but ovarian weights were not affected. In a subsequent study, rats in estrus were sham-operated, unilaterally ovariectomized (ULO), vagotomized, or vagotomized + ULO, and serum levels of LH and FSH were determined at 5 and 24 h. ULO caused a significant (p < 0.05) increase in LH and FSH at 5 h. Vagotomy significantly (p < 0.05) depressed LH and FSH levels in hemiovariectomized animals at 5 h. By 24 h LH was significantly higher in ULO than in either sham-operated (p < 0.05) or vagotomy (p < 0.01) groups. Also, vagotomy significantly (p < 0.01) depressed FSH levels at 24 h. These results suggest a functional role for the vagus nerve in normal cyclic activity, COH, and gonadotrophin (Gn) secretion.

Injections of horseradish peroxidase (HRP) into the right or left ovary of the rat produced labeling of perikarya in both nodose ganglia and ipsilateral dorsal root ganglia (DRGs) from T10 to L2. The greatest concentration of labeled cells was in T13 and L1, DRGs. It is suggested that visceral afferent fibers from the ovary may mediate visceral reflexes that modulate ovarian function.

Recombinant tissue consisting of adult ductal epithelium isolated from pancreas and fetal mesenchyme was transplanted subcutaneously in the inguinal region of nude mice or epididymal fat pads of rats with a tissue chamber device for short-term (8-day) or long-term (6- to 12-wk) duration. We found that recombinant tissue underwent morphogenesis and cytodifferentiation, thereby forming islets that contained cells immunocytochemically positive for insulin and glucagon. Islet cytodifferentiation occurred in approximately 20% of the recombinants. In recombinants that developed into islets, the tissue was always in close association with an extracellular matrix, nerves, and blood vessels. Controls consisting of mesenchyme alone or duct epithelium alone showed no evidence of morphogenesis of cytodifferentiation. Pancreatic rudiments were also implanted to serve as positive controls. This is the first demonstration of islet cytodifferentiation from adult duct epithelium.

Adrenergic and acetylcholinesterase (AChE)-positive nerves were studied in the rat ovary four days after various experimental denervation procedures. Ablation of pelvic parasympathetic nerves (pelvic neurectomy [PN]) or abdominal vagotomy (AV) had no obvious affect on the adrenergic of AChE-positive nerves in the ovary. Section of the mesovarium resulted in the loss of all histochemically demonstrable adrenergic and AChE-positive nerves. Chemical sympathectomy with 6-hydroxydopamine (6-HD) resulted in the loss of all histochemically demonstrable adrenergic nerves. A few AChE-positive nerves remained in the hilar and medullary regions following chemical sympathectomy. When the presumptive parasympathectomy procedures (AV and PN) were combined with chemical sympathectomy, again no adrenergic nerves remained, however a few hilar and medullary AChE-positive fibers persisted after sympathectomy plus PN, but no AChD-positive fibers were demonstrable in the AV plus 6-HD group. These findings show that most of the AChE- in ovarian nerves is localized in adrenergic nerves. It is suggested that the few AChE-positive fibers remaining in the ovarian hilar area after 6-HD treatment of 6-HD plus PN are derived from the vagus. These few AChE-positive nerves may be postganglionic vagal parasympathetic or they may be sensory fibers.

Abdominal vagotomy of estrus or proestrus rats resulted in disruptions of the estrous cycle which was characterized by prolonged periods of diestrus (10–12 days in length). In contrast, vagotomy on metestrus or diestrus did not disrupt the estrous cycle. The induction of pseudopregnancy, in response to cervical stimulation on the morning of estrus, was also interrupted by abdominal vagotomy. The nocturnal and diurnal prolactin surges and elevations in serum progesterone, characteristic of pseudopregnancy, were prevented by vagotomy. Vagotomy, also, largely prevented the formation of deciduoma in response to traumatization of the uterus in cervically stimulated rats.

The autonomic innervation of the interstitial gland of the rat ovary was studied on days 4, 6, 10, 14 and 18 of pregnancy with the acetylcholinesterase procedure, the Falck-Hillarp technique and electron microscopy after 5-hydroxydopamine treatment. Acetylcholinesterase-positive nerves were present as perivascular plexuses at all stages studied. Adrenergic nerves were present in the interstitial gland in all stages studied. The number and intensity of interstitial fluorescent adrenergic nerves increased as pregnancy progressed. Measurement of norepinephrine with the fluorometric procedure showed a highly significant (p less than 0.05) increase in the neurotransmitter in the ovary on days 14 and 18 as compared to day 4. Fine-structural studies after administration of the false transmitter, 5-hydroxydopamine, showed that the innervation of the steroidogenic cells of the interstitial gland is adrenergic.

Following unilateral ovariectomy in the rat, the remaining ovary undergoes rapid compensatory changes including an increase in the number of antral follicles (follicular activation) and an increase in ovarian weight (compensatory ovarian hypertrophy). The ovary is innervated by the vagus nerve (Burden et al., 1983). In the present study, the effects of right and left cervical vagotomy and abdominal vagotomy on follicular activation and compensatory ovarian hypertrophy in the remaining right or left ovary were compared 15 days after unilateral ovariectomy. Neither right nor left cervical vagotomy affected compensatory ovarian hypertrophy of the right or left ovaries but abdominal vagotomy depressed compensatory ovarian hypertrophy in both the right and left ovaries. Left cervical vagotomy did not inhibit follicular activation, but right cervical vagotomy prevented follicular activation in the right but not left ovary. Also, abdominal vagotomy inhibited follicular activation in the right but not the left ovary. In animals with both ovaries which were subjected to the left or right cervical vagotomy or abdominal vagotomy follicular counts in both right and left ovaries were similar. Collectively, these data indicate that the vagus nerve participates in follicular activation after unilateral ovariectomy. The data also indicate that the right ovary is more dependent on vagal influences for follicular activation than the left ovary.