Fifteen cats and five dogs were decerebrated at the midcollicular level and then cordotomized at the twelfth thoracic level. We observed an abrupt augmentation of respiration as a previously undefined effect within the Schiff-Sherrington phenomenon in decerebrate cats immediately upon the transection of the spinal cord, averaging a 56% increases in minute volume (P<0.005). The results are interpreted as pointing to the presence of a neuromechanism linking the increased ventilation with enhanced somatic neuromuscular effects and/or by the release of postural inhibitory reflexes in the Schiff-Sherrington phenomenon as accompanied by the release of respiratory activity, or some combination of systems.
The chick chorioallantoic membrane (CAM) assay was applied for the determination of angiogenic substances. The pseudo-peroxidase activity of erythrocytes was used as a marker of blood capillaries growing in CAM during days 6-14 of incubation. The CAM reaction induced by eye contact lenses, agarose gels, egg shell membranes, and Millipore and glass fiber filters implanted during days 6-10, 6-14, or 10-14 of incubation, was examined by light microscopy. Contact lenses, agarose gels and Millipore filters were soaked in [3H]histamine. The amount of radioactivity was determined in the supernatant of each carrier material incubated in vitro for 4 days, or in the CAM implants during days 10-14 of incubation. Formation of the capillary network in the chorionic epithelium was not complete on day 10 of incubation, but was complete on day 11. Contact lenses always caused capillary involution in the chorionic epithelium. Different carrier materials caused various types of inflammation, i.e. erosive, ulcerous or the granulomatous and ulcerous. In general, the carriers elicited a stronger inflammation when implanted during days 10-14 than during 6-10 or 6-14 of incubation. [3H]Histamine was released continuously from carrier materials during 4 days of incubation in vitro. In contrast, [3H]histamine release from implants in vivo lasted only for 1 day. We conclude that data obtained by the CAM assay are subject to certain restrictions.
In the rat hypothalamic tuberal region, the distribution of aromatic L-amino acid decarboxylase (AADC)-immunoreactive cells was compared with that of tyrosine hydroxylase (TH)-immunoreactive cells. Two types of AADC-immunoreactive cells were found in the tuberal region; strongly stained cells with distinct processes and weakly stained cells visualized only after colchicine treatment. Most of the intensely AADC-immunoreactive cells were restricted to the dorsomedial arcuate nucleus and neighbouring periventricular nucleus. The second type of AADC-immunoreactive cells was found in the ventromedial and lateral parts of the nucleus. In the ventrolateral part of the arcuate nucleus and its neighbouring periarcuate region, we identified a dense aggregate of TH-immunoreactive cells, but there were no AADC-immunoreactive cells in the homologous region.
Two enzymes capable of degrading the protein core of proteodermatan sulphate were isolated and partially purified in latent form from medium conditioned by the culture of fibroblasts from human gingiva. One of these enzymes had a pH optimum of close to 7 and the other of close to 6. The molecular weight of the latent ‘neutral’ proteinase, determined by gel-filtration chromatography, was 48,000, decreasing to 37,000 and 19,000 on activation by limited proteolysis with trypsin. For the ‘acidic’ proteinase the molecular weights for latent and active forms were 68,000 and 57,000, respectively. Both enzymes were inhibited by ethylene-diaminetetra-acetic acid and by 1,10-phenanthroline but not by N-ethylmaleimide, phenylmethanesulphonyl fluoride, leupeptin or pepstatin. They are therefore probably metalloproteinases. Limited digestion of proteodermatan sulphate with either enzyme yielded a large fragment including about 200 amino acids from the aminoterminus and the dermatan sulphate chain, together with a number of smaller fragments derived from the C-terminal portion of the core. Prolonged digestion resulted in conversion of the large fragment to small peptides.
Scatchard analysis of angiotensin II (A II) binding data revealed different effects of dithiothreitol (DTT) on high-affinity AII receptors in the bovine adrenal and ovary. Dithiothreitol predominantly inhibited 125I-A II binding capacity of adrenal membranes by decreasing the number of the high-affinity binding sites (Bmax=265±5 fmol/mg of protein without DTT; Bmax=26±5 fmol/mg of protein with 100 mM DTT) without significant change in A II binding affinity (Kd=0.49±0.02 nM vs. Kd=0.37±0.10 nM). By contrast, in the ovary the agent stimulated 125I-A II binding capacity up to 3-fold by increasing A II binding affinity of the high-affinity receptors (Kd=0.22±0.04 nM vs. Kd=0.041±0.015 nM for 0 mM and 100 mM DTT, respectively) with no change in the number of binding sites (Bmax=72±13 vs. 85±8 fmol/mg of protein). These results suggest the existence of two distinct subtypes of A II receptors between the two tissues.
To elucidate mechanisms of elevated resting fluid secretion in hypertrophied pancreas produced by the oral administration of a synthetic protease inhibitor (FOY-305) once a day for 3 weeks, the influence of the ionic environment and transport blockers was studied in the isolated perfused rat pancreas. The rate of resting fluid secretion of the perfused hypertrophied pancreas during the perfusion period of 3 h was 7 times higher than that of the control pancreas. The elevated resting fluid secretion in the hypertrophied pancreas was reduced by perfusion with K+-free, low Na+, low Cl- or HCO3--free solution. The elevated fluid secretion was reduced by perfusion with ouabain or amiloride, but was not by furosemide or SITS. The elevated fluid secretion was reduced by anoxic treatment or by perfusion with 2,4-dinitrophenol. The inhibition of the hypertrophied pancreas in various ionic environments and with various inhibitory agents was not observed in the perfused control pancreas. These results led us to conclude that the enhanced level of resting fluid secretion in the hypertrophied rat pancreas may be maintained by three major transport systems working cooperatively each other; i.e. NaK-ATPase activity, amiloridesensitive Na-H antiport system, and a unique Cl- transport system, which is insensitive to furosemide and to SITS.
The relation between gastrin-releasing peptide (GRP)-immunoreactive nerves and development of stomach ulcers was studied in rats. The ulcer was induced by exposure of animals to restraint plus water immersion or by administration of insulin, serotonin, aspirin, indomethacin or ethanol. Immunohistochemistry demonstrated a network of nerves exhibiting the immunoreactivity for GRP in the oxyntic mucosa of normal animals. A marked decrease in number of the GRP-immunoreactive nerves was seen to accompany with the ulcers induced by the restraint stress or by insulin. On the other hand, no appreciable change in number of the GRP-immunoreactive nerves was found in ulcers induced by indomethacin, serotonin, ethanol or aspirin. Vagotomy prevented not only the development of ulcers by stress or insulin, but also the decrease in the GRP-immunoreactive nerves. Electrical stimulation of the vagal nerve resulted in ulcer formation and also caused a marked decrease in number of the GRP-immunoreactive nerves in the oxyntic mucosa. The results suggest the possibility that depletion of GRP from nerves in the oxyntic mucosa may be involved in the development of stress or insulin ulcers and that such a release of GRP may be caused by hyperactivity of the vagal nerve.
Changes in the level of type IX and type II collegen mRNA were examined during the course of chick limb development in vivo using cloned cDNA probes. Substantial amounts of type IX and type II collagen mRNA were detected at stage 26, concurrently with the chondrogenic differentiation of limb mesenchyme. Subsequently, the amounts of type IX and type II collagen mRNA showed parallel and marked increases corresponding to the progressive accumulation of cartilage matrix in the limb. Type IX and type II collagen synthesis also increased coinciding with a dramatic increase in their respective mRNAs. The present study suggests that type IX and type II collagens are coordinately expressed during the course of limb cartilage differentiation, which would enable the formation of a very precise temporal and spatial arrangement of cartilage matrices.
Virus-like particles were found in the Shionogi carcinoma 115 (SC-115) cells. SC115 cells are known as an androgen-dependent mouse mammary tumor. Ultrastructural examinations of androgen-dependent growing tumor cells showed virus-like particles with outer diameters of about 83 nm, exclusively in the cisternae of the rough endoplasmic reticulum and the nuclear envelope. The particles were also observed in all of the mitotic cells examined. The number of particles in SC-115 cells increased with tumor growth after transplantation of cells into male mice. However, no virus-like particles were seen in the tumor cells transplanted into castrated male mice. A relationship is proposed between the appearance of viruslike particles and androgen-dependent oncogenesis of SC-115.
Nebulin, a high molecular weight (~700 kDa) protein of vertebrate skeletal muscle, was not detected in embryonic and adult cardiac muscles of the chicken by SDS-gel electrophoresis. No peptides reactive with anti-nebulin antiserum were found by immunoblot tests. Nebulin was detected in chicken embryonic skeletal muscles after 17 days of incubation. On the other hand, connectin, another giant protein, was present in both cardiac and skeletal muscles of the chicken embryos after 15 days of incubation.