Biomedical subjects
Publications and source records attributed to O Thorlacius-Ussing.
Selenium accumulated in the anterior pituitary of the rat after intraperitoneal injection of NA2Se03. Selenium is bound to a cation (most likely Zn++) and is ultrastructurally located in lysosomes and secretory granules.
Two histochemical methods, Timm's sulphide silver method and the selenium method reveal the presence of two pools of metal ions in the Paneth cells. Ultrastructurally one pool is located in the secretion granules, the other in the cytoplasm.
A histochemical technique has been used to reveal mercury deposits by light and electron microscopy in the anterior pituitary of adult rats. After administration of mercuric chloride either in the drinking water or by intraperitoneal injection, deposits were found within lysosomes and secretory granules in somatotrophs, thyrotrophs, follicular cells, and marginal cells. The amount of mercury deposited was proportional to the dose of mercuric chloride given. Significantly more mercury was found in rats given intraperitoneal injections compared to those intoxicated with mercuric chloride in the drinking water. Mercury was retained in the cells for at least 4 months after the last injection although the amount of deposits decreased in this period.
Metal selenide accumulations were demonstrated in the anterior pituitary of the rat by a histochemical technique at light and electron microscopic levels. After administration of sodium selenite either by drinking water (2.5 to 15 ppm) or by ip injection (5 to 20 mg/kg body wt), intracellular accumulations were found in secretory granules and lysosomes of the somatotrophs, thyrotrophs, corticotrophs, and the gonadotrophs. The amount of countable deposits increased with increasing doses, whether selenite was given in drinking water or by ip injection. Localization of deposits was independent of route of administration. Following a single ip injection of 5 mg sodium selenite/kg, a steadily increasing amount of visible deposits was seen throughout the first week. After this peak the deposits started to decrease but could still be found after 2 weeks. Selenium may possibly create bonds to endogenous zinc in the anterior pituitary as has been suggested for the brain.
The localization of gold in normal, stimulated and activated mouse peritoneal cells exposed in vivo to sodium aurothiomalate was examined by a new histochemical technique based on physical development. Activated macrophages from mice infected with herpes simplex virus type II showed the greatest amount of gold localized within lysosomes. Mast cells contained gold in their granules. Polymorphonuclear leucocytes and lymphocytes, on the other hand, were devoid of gold. Pinocytosis is discussed as the mechanism by which gold is taken up into the cells.
Silver accumulations in the anterior pituitary of argyric rats were demonstrated using a histochemical method that visualizes minute traces of the metal. Silver was localized intra- and extracellularly throughout the anterior pituitary. Intracellular deposits were found within the lysosomes of somatotrophs and gonadotrophs. Extracellularly, the grains were located in basal laminae of portal veins and sinusoidal capillaries and in the membrane separating the anterior pituitary and part intermedia. The amount of deposited silver was dependent upon the dose of silver administered. Increasing the dose of silver lactate from 10 to 30 mg resulted in increased deposition, whereas a further increase to 60 mg did not alter the amount of silver deposited.
The ultrastructural localization of gold in the anterior pituitary of rats injected intraperitoneally with sodium aurothiomalate has been demonstrated using a histochemical technique that visualizes minute traces of gold. Gold was located intracellularly within lysosome-like bodies of marginal layer cells, follicular cells, and thyrotrophs. Gold was not seen within secretion granules. The possible mechanism by which gold is taken up into the cells is discussed.
This paper describes a modification of a cytochemical method for the demonstration of heavy metals. The well localized precipitate in the mast cell granules, which is also present in granules that have been separated from the cell, suggest that the metals are localized in the granules. It is demonstrated that "mast cell" grown cultures do not contain precipitate. The chelating and histamine inhibiting agent 8-hydroxyquinoline produced no changes in the histochemical pattern of the mast cell granules before nor after treatment with the histamine liberator 48/80 which provokes a release of granules from the cells. These observations suggest either that the metal (zinc) is bound to the granules in such a manner that the chelating agent cannot chemically, or based on the configuration of the metal-containing molecule, reach the metal and thereby prevent its transformation to a metal suphide.
A histochemical technique which permits the simultaneous visualization of heavy metals and acid phosphatase at the ultrastructural level is described. The technique was applied to the anterior pituitary gland, the spinal cord and the liver. In all of the tested organs, both mercury and silver were found to accumulate primarily in the lysosomes, although small amounts of both metals could be observed in other organelles including endocytotic vesicles. In the anterior pituitary, few mercury deposits were found in the secretory granules.
In order to investigate the selenite metabolism in the anterior pituitary and compare it with other endocrine organs, rats were injected intraperitoneally with 75Se sodium selenite (5 mg/kg). The rats were whole body counted shortly after injection and recounted just before sacrifice, which was performed 2, 24, 48 h, and 4, 10, 20, 30, 40, 60, and 80 d after injection. Besides the anterior pituitary, the selenium content was also estimated in the thyroid gland, testis, adrenals, liver, kidney, and blood. The maximum selenium content was observed in all organs 2 h after injection, at which time the anterior pituitary contained 2.9 micrograms/g wet wt, compared to 13.5 micrograms/g wet wt in liver and .6 micrograms/mg wet wt in testis. The excretion of selenite from the anterior pituitary resembled that seen in most other organs investigated, i.e., an initial rapid excretion and a slower secondary phase resembling a first order reaction. Practically all selenium was excreted by 60 d after injection. The selenium content in pituitaries from untreated rats was estimated by PIXE analysis to be 2.2 +/- .1 micrograms dry wt and .48 +/- .03 micrograms/g wet wt. From the present study it can be concluded that selenium in the form of selenite accumulates in the anterior pituitary after a single intraperitoneal injection; selenite is excreted from the gland in a biphasic manner; practically all selenium is excreted within 60 d; and pituitaries from normal rats contain .48 micrograms selenium/g wet wt.