摘要:

Distribution of vitamin D-dependent calcium-binding proteins (CaBPs) were studied in four mammalian species using monospecific antibodies raised against chick duodenal CaBP (D-CaBP), human cerebellar CaBP (L-CaBP), and rat duodenal CaBP (S-CaBP). The immunoperoxidase technique of unlabelled antibodies was employed. The distribution of D-CaBP/L-CaBP was identical in all the species studied except for the monkey, in the rat, pig, and human nephrons, D-CaBP/L-CaBP was seen in the cytoplasm of the cells of the distal convoluted tubules, initial segments of the collecting ducts and interspersed cells of the collecting ducts. Proximal convoluted tubules, glomeruli and maculae densae were negative. In the monkey, in addition to the cells of the distal convoluted tubules, the cells along the entire length of the collecting ducts were also strongly positive. S-CaBP was found to be species-specific, and hence positive results were obtained only in the rat nephron. The strongest positive reaction for S-CaBP was seen in the cells of the distal convoluted tubules. These same cells were also positive for D-CaBP/L-CaBP. S-CaBP was also detected in the cells of the thick ascending limb of the loop of Henle, along the entire length of the collecting ducts and in smaller amounts in cells of the macula densa. Intracellularly the S-CaBP was present only in the apical cytoplasm of positive cells. D-CaBP/L-CaBP stained the entire cytoplasm but the staining in the apical cytoplasm was denser.

ISSN:1422-6405    

DOI:10.1159/000145765

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The structure of parenchymal components of rat submandibular glands observed with scanning electron microscopy is presented. The glands were fixed, submerged in liquid nitrogen, cryofractured, dehydrated and critical-point-dried. The fracture surface displayed the acini, granular ducts and striated ducts. Acini exhibit a typical sponge-like pattern of irregular and empty cavities. Granular ducts are lined by bulging cells laden with numerous secretory granules. Their diameter ranged from 0.2 to 3.2 μm, with a mean value of 1.240.4 μm. Measurement of the actual granules was rendered possible by direct observation. Striated ducts exhibited a cribiform pattern near the basal cell region which corresponds to infoldings of the basal cell membran

ISSN:1422-6405    

DOI:10.1159/000145766

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The ultrastructural and histological characteristics of the filiform papillae of the cow tongue are described. These large, conical papillae display a fully keratinized external projection, which demonstrates a dominant hard keratin core partially ensheathed by soft keratin. This biostructure differentiates from a dominant posterior cell line, leading to the hard keratin core, and a thinner anterior cell line which, with contributions from an inter-papillary cell line, appears responsible for an attenuating sheath of soft keratin around the hard keratin core. The hard keratin cell line differentiates from cells devoid of keratohyalin granules (KHG), which are rich in thick bundles of tonofilaments. The soft keratin cell line differentiates from cells containing both eosinophil and basophil KHG and dispersed tonofilaments. The bovine filiform papilla also appears similiar in biostructure to the mammalian hair shaft and the ‘filiform hairs’ of the rat pe

ISSN:1422-6405    

DOI:10.1159/000145767

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

To study the in vivo effects on bone formation in standardized bone growth and remodelling systems, a moderate supplement of vitamin D metabolites was given adolescent rats on a standard diet. Comparison with other hormones previously shown to stimulate the bone formation in these systems is thereby facilitated. Female rats (10 animals per group) were given one daily subcutaneous injection of 1.5 µg/ kg 25-OHD3 or 0.04 µg/kg 1,25-(OH)2D3 for 20 days (75–94 days of age). Controls were given 0.5 ml solvent. Tetracycline was used as intravital marker to determine the longitudinal bone growth of proximal tibia as well as the apposition and resorption of cortical bone in the femur diaphysis. The osteoclasts were counted in the metaphysis and diaphysis of the ribs. Vitamin 1,25-(OH)2D3 resulted in retardation (p$0.05) of the accumulated longitudinal bone growth. A similar but insignificant tendency was found for 25-OHD3. The body weight and the periosteal and endosteal bone formation at various levels along the femoral shaft were unchanged compared to the controls. The total cortical width was somewhat lower in the distal femur for 1,25-(OH)2D3. In the proximal femur 25-OHD3 resulted in a somewhat thicker cortical bone. Most levels along the femur, however, showed no differences. The osteoclast count showed an increased number (p $ 0.05) in the cortex of the rib in the rats given 1,25-(OH)2D3. Compared to growth hormone, which is the major bone growth stimulating agent, the influences on bone formation of the vitamin D metabolites were minor and predominantly negat

ISSN:1422-6405    

DOI:10.1159/000145768

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The goitrogen methylthiouracil was administered orally to pregnant ewes of known gestational ages to induce hypothyroidism in both mother and fetus. Developing pituitary thyrotrophic cells were studied using electron microscopy to detect the earliest gestational age at which morphological changes occurred in response to lowered plasma thyroid hormone concentrations. At 50 days of gestation, the pituitaries of fetuses exposed to the goitrogen were indistinguishable from untreated control glands. However, at 58 days and subsequent ages, ‘thyroidectomy’ cells were observed in pituitaries of all hypothyroid fetuses. These findings indicate that fetal sheep pituitary thyrotrophs are sensitive to lowered thyroid hormone concentrations by 58 days of gestation, suggesting that thyroid-thyrotroph interaction exists at this early stage of developm

ISSN:1422-6405    

DOI:10.1159/000145769

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

A comparison has been made of the vertebral muscle fiber characteristics between human and rhesus monkey. The main purpose of the experiment was to asses the value of the monkey as an animal model for the study of idiopathic scoliosis involving vertebral muscle influence. Vertebral muscle samples were collected from both clearly defined superficial and deep sites on both sides of the column in the midlumbar region. The material was subjected to routine histological and histochemical techniques. The results show considerable similarities between the deep muscle samples of the two species, but the superficial muscles are significantly different on most of the measurements made.

ISSN:1422-6405    

DOI:10.1159/000145770

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The cholinergic innervation of the pulmonary circulation was studied in man. Both extra- and intrapulmonary branches of the pulmonary artery and vein are provided with a cholinergic of the vein. In the main branches of the pulmonary vessels, the existence of two nerve plexuses, a superficial and a deep one, was observed. The superficial plexus is localized in the outer adventitial layer while the deeper plexus is localized in the adventitial-medial transitional zone. In smaller arteries and veins, the existence of a single plexus (adventitial-medial) was observed. In some specimens, the presence of diffuse masses of acetylcholinesterase (AChE)-positive material or elbow-shaped AChE-positive formations was observed. The nature of these formations as well as the possible functional role of a cholinergic system in the pulmonary circulation are discussed.

ISSN:1422-6405    

DOI:10.1159/000145771

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The histology and histochemistry of the parotid, submandibular and sublingual glands were studied. The submandibular gland contained only serous acini as in the guinea pig, but unlike in many other mammals. The parotid gland contained only serous acini while the sublingual gland was mixed, mucous acini being the predominant secretory tissue interspersed by a few serous acini. Serous demilunes also commonly formed caps on the mucous acini. The ducts of the gland contributed over 30% of the volume of the submandibular gland, while those of the parotid and sublingual glands formed about 12 and 10% of the gland, respectively. The secretions of the parotid gland, as judged by histochemical methods, contained neutral mucins and some sialomucins. Neutral mucins, sulphomucins and sialomucins were detected in both the submandibular gland and sublingual gland.

ISSN:1422-6405    

DOI:10.1159/000145772

出版商:S. Karger AG    

年代:1983

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000145773

出版商:S. Karger AG    

年代:1983

数据来源: Karger