The presence of atrial natriuretic peptide (ANP) in the striated myocytes of pulmonary veins in rat was studied by immunohistochemical methods. In general, the immunoreactivity of the pulmonary myocardium was less intense than found in the left atrium. In the inner circular layer of the pulmonary myocardium, some striated myocytes were moderately granular stained. The staining was mainly localized to the paranuclear areas, while some granules were also distributed throughout the sarcoplasm.
Mixed tumors of sweat gland in the skin were stained by the peroxidase antiperoxidase (PAP) method using antibodies to S-100 protein, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), and keratin proteins, in order to evaluate possible histogenesis of the tumors. Secretory coiled cells in normal eccrine glands were moderately positive for S-100 protein, markedly positive for NSE, and negative for GFAP, and they displayed variably intense staining with anti-keratin antibodies. In mixed tumors of the skin, the round, oval or polygonal cells located in the outer zone of tubular or duct-like structures, were usually strongly positive for S-100 protein, gave reactions of varied intensity for NSE, and were generally negative or very weakly positive for GFAP. Spindle-shaped cells were negative or very slightly positive for S-100 protein and strongly positive for NSE; but the reaction for GFAP varied. Tumor cells located on the luminal side of tubular or duct-like structures were uniformly positive for KLl (molecular weight 55-57 Kdaltons keratin) and PKKl (molecular weight 41-56 Kdaltons keratin). From the present study, it is suggested that mixed tumors of the skin may be differentiated from either transitional portion or myoepithelial cells of the eccrine glands.
Immunohistochemical localization of myoglobin (Mb) in muscles and kidneys was examined in three autopsy cases of rhabdomyolysis with acute renal failure. In the skeletal muscles, Mb immunoreactivity was lost in some degenerated fibers which was not expected by routine histological observations. In the kidneys Mb was revealed as fine granules in the epithelial cells of the distal tubules, and as casts in collecting ducts. These findings confirmed that Mb leaked from myolytic fibers was partly reabsorbed, but mostly accumulated as Mb-casts in the collecting duct of the kidney, and caused an acute renal failure. Thus, Mb immunohistochemistry is helpful in identifying the direct process of acute renal failure caused by rhabdomyolysis.
Distribution of GABA-like immunoreactive neurons in the rat locus ceruleus was investigated by applying the peroxidase-antiperoxidase method with a GABA-antiserum to the thin, consecutive frontal paraffin sections counterstained with cresyl violet. Nuclear sizes of 1155 immunoreactive neurons in and around locus ceruleus on alternate 240 sections and 313 noradrenergic neurons in both divisions were measured and analysed statistically. The density of distribution of GABA-like immunoreactive neurons was low in the dorsal division (12.5%, 354/2815) and perinuclear zone (16.4%, 539/3285), but rather high in the ventral division (55.6%, 262/470). Intrinsic GABAergic neurons could be divided into medium-sized and small ones (3.9% and 8.6% of total neurons in the dorsal division, respectively) (P<0.005). Both types of total immunoreactive neurons (Mean nuclear volume±Standard error) (169.8±5.6μm3 and 99.3±2.5μm3) within locus ceruleus were significantly smaller than noradrenergic ones (220.2±5.5μm3 and 126.9±4.5μm3). Immunoelectron microscopy showed that only 7.5% (19/253) of axo-somatic boutons on immunonegative medium-sized neurons were GABAergic. From these observations, it is suggested that the organized GABA system, different in size from a noradrenergic system, is distributed all over the locus ceruleus.
Some metabolic activities in the spinal cord of the rat during embryonic development were investigated by using cytochemical techniques for calcium-dependent adenosine triphosphatase (Ca2+-ATPase) and alkaline phosphatase (AlPase). Under light microscopy, the roof and floor plates of the primitive spinal cord at embryonic day (E) 12 clearly showed high Ca2+-ATPase activity, whereas the lateral plates, in contrast, had marked AlPase activity. In the later stages of development, the lateral walls also exhibited Ca2+-ATPase activity. Under electron microscopy, reaction products for the Ca2+-ATPase activity in the roof and floor plates were mainly localized in the lateral plasma membranes, including many cytoplasmic processes, of these plate-forming cells. These findings indicate that the roof and floor plate-forming cells are different in enzyme activity from the proliferative cells of the lateral walls during embryonic development. The possible roles of Ca2+-ATPase in the membrane activity of early differentiated neuroepithelial cells during the embryonic development of the spinal cord are discussed.
The histochemical activities of acid phosphatase and dipeptidyl peptidase II were determined quantitatively in regenerating rat soleus fibres up to five weeks after an ischaemic insult with 5-hydroxytryptamine. A measure of the total enzyme content per fibre was determined by multiplying mean fibre area by the mean absorbance of the enzyme final reaction product. Acid phosphatase content was 21% lower than control levels during the first two weeks and 18% higher in the remaining three weeks; the mean absorbance of the reaction product correlated significantly with fibre area (r=0.922). Dipeptidyl peptidase II activity was 14% lower during the first three weeks, 2% higher in the fourth week and 14% higher in the fifth week. The correlation of mean absorbance of the reaction product of this enzyme with fibre area (r=0.792) was not as good as for acid phosphatase but was significant.
Sprague-Dawley female rats were administered 10mg/Kg of Bromocriptine by intubation daily for 3 weeks from 31 to 51 days of age. Tail blood was collected for RIA of PRL from meta- and di-estrus rats at the age of 51-55 days. Sampling was not repeated in any rat. A rebound increase in serum PRL levels occurred within 3 days after the cessation of subchronic treatment. Quantitative immunoelectron microscopy using the protein A gold method was carried out in some pituitary tissues from the PRL-determined rats. Compared with the controls, excessive accumulation of higher gold-labeling mature secretory granules was found in PRL cells and also the Golgi complex was less developed in the treated rats just after the last intubation. The PRL cells exhibited more extrusion of secretory granules 2 days after the cessation when their ultrastructural features were almost completely restored. These data indicated that a rebound in serum PRL levels is accompanied by marked changes in the ultrastructural characteristics of the PRL cells.
Cryosectioning and autoradiographic techniques to estimate and compare the radioactivities in various regions of the tubular organs were established in small experimental animals after injection of RI compound. The cryosectioning involved the entire extent of a tubular organ, such as the alimentary tract and the uterine tube of mice. H-E staining of cryosections was sufficient to distinguish histological features in each region of the tubular organs under low power magnification. In mice injected with 14C-glucose or 14C-mannose, autoradiographs of alimentary tract and pregnant uterine tube gave much useful information concerning the regional differences in the distribution of radioactivity in these tubular organs.
Tissue and organ distribution of radioactive carbon from 14C-tyrosine in the mouse was studied by whole-body autoradiography and biochemical analysis. The mice injected intravenously with L-[U-14C]tyrosine were sacrificed at various intervals. Examination of autoradiographs disclosed that the injected 14C-tyrosine was rapidly taken up from the blood by the tissues. The radioactivity in the pancreas was the highest and predominant throughout the intervals after injection in this investigation. The comparative values among radioactivity in the organs estimated by a liquid scintillation counter were approximately consistent with those obtained from the whole-body autoradiographs. Radioactivity in the acid-insoluble fractions was increased with time in all organs examined. High-performance liquid chromatography of the acid-soluble fractions disclosed that the amounts of the radioactive tyrosine and its metabolites and/or their molar ratios were different among the organs.
Acid phosphatase (ACPase) activity in the sea urchin ovary, Hemicentrotus pulcherrimus, was investigated by ultracytochemistry. There were significant differences in the ACPase active structures according to the morphological changes of the ovarian cycles of the sea urchin ovary. ACPase active structures appeared mainly in the cytoplasm of the nurse cells, whereas in other cells in the ovary almost none. In the nurse cells reaction products were located in 1) spherical granules, about 1-3μm in diameter, which consists of fine granules, 2) some kinds of giant granules and 3) irregularly shaped dense bodies. The reaction products also appeared in a small number of tubules, but not in Golgi apparatus nor nucleus. In the oocytes reaction products were appeared very weakly in the yolk granules during and immediately after the breeding season. It is considered that the above three types of ACPase reactive structures are equivalent to 1) primary lysosome, 2) secondary lysosome which corresponds to the digesting relict ova that were phagocytized by nurse cells after the breeding season and 3) residual body. The morphogenesis and behavior of the giant granules are discussed.