Ultrastructure of rat ovarian interstitial gland cells during pregnancy

Abstract

The fine structure of the interstitial gland of the rat ovary was studied at estrus and on Days 4, 6, 10, 14 and 18 of pregnancy. At estrus, ovarian interstitial cells have small nuceli with dense irregular clumps of heterochromatin. Mitochondria are small and rod-shaped and have predominantely lamellar cristae. Numerous osmiophilic lipid droplets are present. At Days 4 and 6, nuclear heterochromatin is reduced, and nucleoli are larger and complex. Mitochondria are enlarged and often bizarre-shaped and have tubular cristae. Golgi and smooth endoplasmic reticulum are more conspicuous. At Day 10, prominent ultrastructural features include nuclei with conspicuous heterochromatin, smaller mitochondria with both lamellar and tubular cristae, numerous ribosomes and lipid droplets with decreased osmiophilia. At Days 14 and 18, nuclei have increased heterochromatin, mitochondria are small and have lamellated cristae and an increase in the size and number of lipid droplets occurs. These observations suggest that steroidogenic activity of interstitial cells is highest during the first half of pregnancy and regresses during the last half. It is suggested that the interstitial gland is an important ovarian source of pregnancy hormone(s) during the first half of gestation and that LH may modulate steroidogenic activity is this ovarian component.

Ultrastructural features of ovarian interstitial tissue in a wild mouse, Apodemus flavicollis, at various reproductive stages, with a note on its histochemistry at the onset of the breeding period

“…This appearance of the interstitial tissue in the visibly pregnant A . jiavicollis agrees well with that of the rat observed by Lawrence et al (1977) during the second half of the gestation period. Interstitial cells in the rat are well differentiated throughout the first half of pregnancy; thus the period of steroid secretion is longer in the rat than in A .…”

“…Cilia have also been found in the interstitial tissue of the guinea pig (Quattropani 1977) and rat (Lawrence, et al 1977).…”

“…The ultrastructure of ovarian interstitial tissue in the rat during pregnancy has been studied by Lawrence et al (1977), who suggested that the steroidogenic activity of interstitial cells was highest during the first half of pregnancy, and that ovarian interstitial tissue is an important source of pregnancy hormone(s) .…”

Morphological and Endocrine Study of the Ovarian Interstitial Tissue of Viscacha (Lagostomus maximus maximus)

“…They observed that the number and intensity of interstitial fluorescent adrenergic nerves increased as pregnancy progressed. Subsequently, Lawrence et al (1977) analyzed the fine structure of rat interstitial cells during the same reproductive condition. This time, they observed ultrastructural features that suggest higher steroidogenic activity during the first half of pregnancy and regressive activity during the second half.…”

“…Some authors have observed morphological characteristics that suggest steroidogenic activity during pregnancy in the interstitial tissue (Lawrence et al, 1977; Garcia et al, 1984). Furthermore, there is evidence that the gonadotrophins, principally the luteinizing hormone (LH), may modulate the development and steroidogenic activity of this ovarian compartment (Carithers and Green, 1972; Capps et al, 1978; Clarke and Brook, 2001).…”