Search

New Zealand male rabbits were exposed in an inhalation chamber to 3,000 ppm of n-hexane 8 h/day, 5 days/week for 24 weeks, resulting in a total of 120 exposures. After a further 120 days in clean air, morphologic examination of lungs by light and transmission electron microscopy (TEM) revealed three important exposure-related lesions. These consisted of air space enlargement centered on respiratory bronchioles and alveolar ducts (centriacinar emphysema), scattered foci of pulmonary fibrosis, and papillary tumors of non-ciliated bronchiolar epithelial cells. At TEM examination these tumors were rather homogeneous and were found to consist of cells showing both small and large electron dense ovoid granules in their cytoplasmic matrix, a feature that has been described for Clara cells.

In this paper we report the serum antiprotease screening and the biochemical and functional characteristics of neutrophils in a variety of mouse strains with different susceptibilities for developing a protease-mediated injury. C57Bl/6J mice and their mutants tight-skin and pallid have a lower serum elastase inhibitory capacity (-30, -65 and -70% respectively) than other inbred strains (i.e. NMRI and Balb/c, which both have similar values). We demonstrate that these values are a consequence of a decreased concentration of the alpha 1-protease inhibitor for elastase [PI(E)], which is the major serum inhibitor of elastase and cathepsin G. In addition, neutrophil lysosomal dysfunctions characterized by abnormally high contents of elastase and cathepsin G, or defective lysosomal secretion are observed in tight-skin and pallid mice respectively. Another C57Bl/6J mutant with lysosomal abnormalities is the beige mouse. Negligible amounts of elastase and cathepsin G, as well as defective neutrophil degranulation, have been described previously in this strain. We found, however, discrete amounts of a latent form of neutrophil elastase that undergoes a spontaneous activation by a protease-dependent mechanism. We also report that neutrophil cathepsin G in this mouse is tightly bound to lysosomal membranes, but is released in near normal quantities during exocytosis. Cytosolic elastase and cathepsin G inhibitors, which were previously reported as being specific for the beige neutrophils, have also been detected in all the examined strains. Neutrophil functions, lysosomal enzyme content and serum antiprotease screening may represent key elements in the protease-antiprotease balance and may explain the different interstrain susceptibility to developing lesions in which an elastolytic activity has been implicated.

The tight-skin (Tsk) mouse is a genetic model of pulmonary emphysema. In this mouse, right ventricular hypertrophy (RVH) starts to develop at approximately 8 months of age, probably as a consequence of the emphysema. The aim of the present study was to investigate cardiac collagen synthesis, content, and types both before and during the development of RVH. Collagen synthesis, assessed by the [³H]proline incorporation method, was significantly increased in the right ventricle of 3-month-old Tsk mice. This was accompanied by a marked increase in right ventricle collagen content. Collagen typing showed no difference from controls. At 8 months of age collagen synthesis had returned to control values, right ventricular collagen content was elevated but held lower values than at 3 months, and collagen typing showed a prevalence of the more compliant type III. By 16 months of age, right ventricular collagen content had returned to control values and there was a shift in collagen types due to a relative increase of the more rigid type 1. At 24 months of age right ventricular collagen content was increased again and collagen type I continued to predominate. These results suggest a dynamic role for collagen both before and during the development of RVH secondary to emphysema. Copyright 1994, 1999 Academic Press

The rate of protein S-nitrosylation, a reversible process by whichS-nitroso thiol (RS-NO) compounds exchange the NO+moiety with protein SH groups, is essentially governed by two factors, the pKaand the accessibility of the protein sulfhydryl. A useful method of following transnitrosation kinetics of various protein and nonprotein SH compounds with GS-NO is described. When the reaction is carried out in the presence of 1-chloro-2,4-dinitrobenzene and glutathione transferases, the rate of RS-NO formation (RSH + GS-NO → RS-NO + GSH) can be monitored by spectrophotometry at 340 nm in terms of the enzymatic conversion of GSH to a GS conjugate. Unlike methods based on NO release from the S-NO bond, this procedure is rapid and accurate and requires relatively small amounts of thiols. The second order rate constants of S-nitrosylation of human and rat oxy- and deoxyhemoglobin of BSA and other thiols were calculated by this method which confirmed previous results reported in the literature.

The fine structure of the bronchial cilia has been studied in biopsies of eighteen patients with chronic bronchitis and six nonsmoking controls. Abnormal cilia were noted in three of the control subjects and in all the patients with chronic bronchitis. The percentage of abnormal cilia ranged from 0 to 6% in control subjects and from 8 to 28% in patients with chronic bronchitis. Some ciliary abnormalities with changes in the axonemal 9 + 2 pattern of organisation were only detected in patients with chronic bronchitis. Compound cilia with two or more complete axonemes arranged parallel to one another and giant cilia with increased amounts of cytoplasmic matrix were observed in both control and diseased subjects. The possibility that these cilia represent aspects of biological variability or abnormalities of epigenetic origin is discussed. On the basis of the reported data, it is reasonable to suggest that the presence of atypical cilia of epigenetic origin contribute to the severe impairment of mucociliary transport associated with chronic bronchitis.

The structural and elastic properties of the lung depend primarily on the concentration in connective tissue of proteins, collagen and elastin. The relationships between biochemical and morphological aspects of pulmonary damage were studied in 50 male New Zealand rabbit’s, randomly divided into two groups of 25 animals, instilled with 245 IU of pig pancreatic elastase solution or physiological saline. Animals were killed at 8, 15, 30, 60 and 90 days after treatment. The changes in pulmonary morphology and in collagen and elastin content have been studied chemically and by light microscopy. The left lungs were used for biochemical determinations of insoluble elastin and total, insoluble and salt-extractable collagens. Morphometric measurements (mean linear intercepts or Lm) and histologic evaluations were performed on right lungs. Three months after instillation, the elastase treated lungs showed a minimal degree of alveolar wall rupture, and no significant difference in Lm from the control group. Quantitative restoration of normal biochemical parameters preceded connective tissue repair. Statistical evaluations showed significative correlations among Lm, total collagen (p< 0.01) and insoluble elastin/dry weight (p< 0.01). No significant differences between Lm and insoluble elastin, salt-extractable collagen or total collagen/dry weight were found.

Furoyl saccharin, a novel heterocyclic acylating agent which has been previously found to possess a potent inhibitory capacity in vitro for elastase and other serine proteases, has been investigated in vivo in two acute animal models of emphysema. In hamsters, intratracheal (i.tr.) administration of 0.1 mg porcine pancreatic elastase resulted seven days later, in a 42% increase of the mean linear intercept (Lm). Addition of 0.3 mg to 0.3 mg furoyl saccharin to elastase exhibited a partial, not dose-related, but statistically significant inhibition of the increase of Lm. Addition of 1 mg furoyl saccharin (equivalent to a dose of 12.5 mg/kg) completely abolished the increase in Lm.In the rabbit i.tr. instillation of 3.7 mg porcine pancreatic elastase induced within seven days, a 48% increase of the Lm, a 27% decrease of the internal surface area (ISA) of the lungs and a 33% decrease of the ISA corrected to an arbitrary total lung volume of 70 ml (ISA70). Furoyl saccharin given i.tr. 15 min prior to elastase at the doses 3, 10 and 20 mg prevented significantly in a dose-related manner, the changes in Lm, ISA and ISA70. The highest furoyl saccharin dose (equivalent to a dose of 10.8 mg/kg) completely protected against the emphysematous lesion. Additionally furoyl saccharin (20 mg i.tr.) prevented in the rabbit model the depletion in lung insoluble elastin and the increase in salt soluble collagen induced by the elastase administration. These results show that furoyl saccharin also in vivo has a marked antielastase activity.

Ultrastructural abnormalities of spermatozoa and respiratory cilia have been reported in a male patient with Kartagener's syndrome and infertility.In this patient both respiratory cilia and sperm tails showed defects in radial spokes and dynein arms. Such defects are heretofore undescribed in the same subject with immotile cilia syndrome.Absence of both inner and outer dynein arms and absence of the inner dynein arms only were detected in spermatozoa and in respiratory tract cilia, respectively. Moreover, total absence of axoneme was seen in several sperm tails from this patient.The possibility that the features described are of genetic origin is discussed.

Light microscopic examination of the renal tubular epithelium of a female with a rapid progressive glomerulonephritis revealed in several areas the presence of cells bearing ciliumlike structures.At transmission electron microscopy, normal tubular cells appeared to be partially replaced by epithelial cells showing numerous 9×2 cilia and a normally developed basal apparatus. The cilia showed several ultra-structural details (i.e., outer dynein arms, spokes) such as observed in kinocilia of the respiratory epithelium. In addition, a number of poorly differentiated cells showing cilia with a 9 + 0 pattern and at the same time cilia with a 9 + 2 pattern of microtubular arrangement were also seen.The possible biologic significance of these cilia is discussed.