Observations on the Fine Structure of Lutein Cells

Abstract

Corpus luteum formation was induced in 26-day-old rats which were subsequently hypophysectomized and injected with mammotrophic hormone (MH, LTH). Sections of corpora lutea from these animals were examined with the electron microscope and compared with similarly prepared (Caulfield's fixed, Araldite embedded) corpora from normal pregnancy and from controls, the latter consisting of corpora prior to hypophysectomy and corpora from uninjected rats 7 to 14 days after hypophysectomy. Lutein cells from corpora lutea of injected animals and of normal pregnancy are characterized by abundant, tortuous, tubular agranular endoplasmic reticulum and by mitochondria, many of which are disc-shaped with dense matrices and both villiform and lamclliform cristae. The endoplasmic reticulum is most abundant in lutein cells from pregnant animals, in which cells it is in the form of thin, highly tortuous tubules. The form of the lipid droplets seen in cells of stimulated animals varies greatly. Marginal foldings of the lutein cells on the perivascular space were found in all instances. Lutein cells from hypophysectomized animals have a less highly developed agranular endoplasmic reticulum. The mitochondria have irregular outlines and a relatively lucid matrix. The lipid droplets in these cells show less tendency to be extracted, but are not so large or abundant as in the cells of onset controls. Granules believed to contain lipid pigments are common in the lutein cells of these control animals. It is suggested that lutein cells from corpora lutea which are actively secreting progesterone may be readily distinguished from lutein cells from non-active corpora by means of the multiple characteristics enumerated. It is further suggested that mammotrophic hormone has a general effect on the metabolism of lutein cells rather than solely affecting a specific organelle, the abundance or composition of which may be the limiting factor in the production of progesterone.In a previous paper active lutein cells from three species were studied. It was found that these lutein cells were characterized by the presence of marginal folding on the perivascular space, extensive agranular endoplasmic reticulum, and abundant mitochondria with numerous villiform cristae. It is the intention of the present study to examine the structure of inactive as well as active corpora lutea.Since the early studies on a corpus luteumstimulating factor (2, 13, 15) and the dependence of the corpus luteum of the rat on this luteotrophic factor (1,14), the function of mammotrophic

Effect of Prostaglandin F2 on the Ultrastructure and Function of Sheep Corpora Lutea

“…This is at variance with the observations of Bjersing et al (1970) who found "no, or almost no, lipid droplets" in the CL of sheep on Days 10 to 13 of the cycle. The obvious accumulation of lipids in the CL of ewes treated with PGF2(t is an involutionary change and is consistent with the ac¬ cepted view that, during the decline in the secretory activity of a steroid secretory cell, the ability to synthesize lipids is retained but the capacity to convert these lipids to steroid hormones is lost (Deane, 1958;Enders & Lyons, 1964).…”

Changes in ultrastructure of transport systems and in rates of progestin secretion in the corpus luteum during late pregnancy in the rat

“…As described in previous studies (Enders and Lyons, 1964;Enders, 1973;Dharmarajan et al, 1983Dharmarajan et al, , 1985, the CL in this study also had a n extensive interstitial space. The precise role of this space is not known, but it is possible that the fluid within it is substantially mobile and may eventually drain into adjacent blood vessels or, alternatively, into the lymphatic drainage of the ovary.…”

ORGANIZATION AND ACTIVITY IN THE PRE- AND POSTOVULATORY FOLLICLE OF NECTURUS MACULOSUS

“…The smooth-surfaced endoplasmic reticulum is characteristically a well developed cytomembrane system in known steroid-producing cells. Thus, a tubular form of smooth-surfaced endoplasmic reticulum is encountered in the corpus luteum (5,25,26,93), in the interstitial cells of the testis (17,18), and in the adrenal cortex (51,54,73). In addition, steroid-producing cells are characterized by the presence in the cytoplasm of mitochondria, Golgi complexes, lipid, and lysosomes (see 54).…”