The Sympathetic Innervation of the Mammalian Ovary. A Review of Pharmacological and Histological Studies

Abstract

The a i m of this article is to review the literature concerning the nature and function of the sympathetic innervation of the mammalian ovary. We focus our attention upon evidence relating to suggestions that ovarian smooth muscle participates in ovulatory events, and that such participation may be modulated by the local neural supply. Guttmacher & Guttmacher (1921) mentioned that this possibility was first suggested nearly 70 years before they observed smooth muscle-like cells in the follicular walls of sow ovaries and found that isolated follicular walls were contracted by physostigmine and relaxed by adrenaline. However, Claessen (1 947), using polarisation microscopy, was unable to confirm the presence of smooth muscle in the apices of follicles from a number of species, and interest in the Guttmachers' findings temporarily lapsed.In 1967, Jacobowitz & Wallach reported the findings of a histological study of ovaries from cats, monkeys and humans in which they observed catecholamine fluorescence associated with smooth muscle-like cells in the stroma. In 1969, Rocereto, Jacobowitz & Wallach demonstrated that the cat isolated ovary exhibited spontaneous mechanical activity and was reactive to catecholamines. These investigations together with those of Owman & Sjoberg (1966) and Sjoberg (1967) initiated a resurgence of interest in the possibility that the adrenergic innervation of the ovary may play a functional role in ovarian processes; in particular that it might affect the contractility of smooth muscle and so participate in ovulation.With the development of techniques such as electron microscopy and fluorescence histochemistry, together with greater sophistication of pharmacodynamic analysis, an increasing number of publications concerned with the role of smooth muscle and adrenergic innervation in the ovary has appeared in the recent literature.Reference to some of this work is found in the reviews of Marshall (1972, 1973) t and Bell (1972). A comprehensive review devoted specifically to the roles of catecholamines and nerves in ovulation was published by Bahr, Kao & Nalbandov in 1974. Their review described the sympathetic innervation of avian as well as of mammalian ovaries and the possible function of such innervation. They considered evidence relating to several possible roles, including modification of contraction of ovarian smooth muscle, participation in ovulation, and/or control of the ovarian vasculature, and concluded that nerves play some role in ovulation, but that it is not clear how this effect is mediated.

Ovulation after sympathetic denervation of the rat ovary produced by freezing its nerve supply

“…It has not been clearly established whether the ovarian sympathetic nerves play any role in the process of ovulation (Bahr, Kao & Nalbandov, 1974; Mohsin & Pennefather, 1979). Early studies involving abdominal sympathectomy (Sweet & Thorp, 1929;Brooks, 1935) suggested that the ovarian sympathetic nerves were not required for ovulation but results from more recent studies seem inconsistent with these findings.…”

Oocytes are a source of catecholamines in the primate ovary: Evidence for a cell–cell regulatory loop

“…It is commonly assumed that catecholamines reach the ovary exclusively via its extrinsic sympathetic innervation (12). However, ovarian denervation reduces, but does not eliminate, the content of NE in the gland (13), implying the existence of an additional source of catecholamine synthesis.…”

In Vitro Study of the Contractility of the Wall of the Preovulatory Follicle in the Japanese Quail1

“…In vitro contractile experiments have been carried out in various vertebrate species, mainly in eutherian mammals [1][2][3][4]. Most of these experiments have been used to investigate the effects of different metabolic and pharmacological compounds on the contractility of the follicular wall.…”

“…The muscular apparatus of the ovary, mainly of the preovulatory follicle, has been investigated more thoroughly in eutherian mammals than in any other group of vertebrates [1][2][3][4]. Possible functions of the contractile apparatus of mammalian ovarian follicles include aid in follicular rupture [5], collapse of the follicular wall and corpus luteum formation [6], and compaction of the follicle during atresia [7].…”