Smooth Endoplasmic Reticulum Vesicles Research Articles

Morphological changes in the liver of rats treated with a new hypolipidemic agent, S-8527.

Electron microscopy was used to investigate the effect of a new hypolipidemic agent, 1,1-bis[4′-(1″-carboxy-1″-methylpropoxy)-phenyllcyclohexane (S-8527), on the fine structure of hepatocytes of rats, treated with oral doses of S-8527 for 2, 3 or 14 weeks, and the effect was compared with that of clofibrate. Daily doses of 150 or 300 mg/kg of S-8527 caused a qualitatively similar pattern of changes in cell organelles to that caused by clofibrate, such as increased number and size of microbodies, proliferation of tubules and vesicles of smooth endoplasmic reticulum (SER) and deformation of mitochondria. At the same dose level, S-8527 appeared to cause an equal grade of changes to those caused by clofibrate, whereas there was no marked change at dose levels of 10 mg/kg and 30 mg/kg of S-8527. S-8527 was also found to cause less increase in relative liver and a more marked hypolipidemic result than clofibrate.

Estriol levels of cord blood, maternal venous blood, and amniotic fluid at delivery at high altitude

hypoplastic Fallopian tubes and a rudimentary bicorn uterus. One gonad was removed. Microscopic examination of the gonad revealed testicular tissue composed of seminiferous tubules and numerous Leydig cells encircling them (Fig. 1) . Ultrastructurally the seminiferous tubules were lined by Sertoli cells and occasional germ c,ells. Leydig cells were adherent to the outer side of the basement membrane (Fig. 2). Besides topographic distinction these cells could be distinguished on the basis of their cytoplasmic appearance. The cytoplasm of Leydig cells was ultrastructurally most differentiated. It was replete with small vesicles of smooth endoplasmic reticulum, indicating the endocrine origin of this b cell type. In contrast to adult Leydig cells, the vesicles of endoplasmic reticulum were very small and showed no cistemal dilatations. There were also very few mitochondria and profiles of rough endoplasmic reticulum, Only occasionally were there lipid droplets of irregular sire and shape and no dense bodies (so characteristic for the adult Leydig cells) were seen. Although the interstitial cells in the testis of this patient had the basic appearance of steroid hormone-producing cells, they were quite distinct from adult, active Leydig cells. Ultrastructurally we could thus concur with the view of Teter and Boczkowskir that the low output of androgenic hormones in some patients with testicular feminization is due to immaturity of Leydig cells.

Autophagic vacuoles produced in vitro. II. Studies on the mechanism of formation of autophagic vacuoles produced by chloroquine.

Continuous phase-contrast observations have been made on macrophages following exposure to chloroquine. The initial abnormality is the appearance in the Golgi region of small vacuoles with an intermediate density between that of pinosomes and granules. Over the course of 1-2 hr these vacuoles grow larger and accumulate amorphous material or lipid. Pinosomes or granules frequently fuse with the toxic vacuoles. Chloroquine derivatives can be seen by fluorescence microscopy; the drug is rapidly taken up by macrophages and localized in small foci in the Golgi region. Chloroquine continues to produce vacuoles when pinocytosis is suppressed. Electron microscopic studies of chloroquine effects on macrophages preincubated with colloidal gold to label predominately pinosomes or granules suggest that toxic vacuoles can arise from unlabeled organelles. Later vacuoles regularly acquire gold label, apparently by fusion, from both granules and pinosomes. L cells also develop autophagic vacuoles after exposure to chloroquine. Smooth endoplasmic reticulum apparently is involved early in the autophagic process in these cells. Information now available suggests an initial action of chloroquine on Golgi or smooth endoplasmic reticulum vesicles, and on granules, with alterations in their membranes leading to fusion with one another and with pinosomes.