In vitro enzymological analysis of the recombinant soluble form of SEP demonstrated that it hydrolyzes a variety of vasoactive peptides, including endothelin-1, atrial natriuretic peptide, and angiotensin I. This activity of SEP was inhibited by phosphoramidon and the neutral endopeptidase 24.11 specific inhibitor thiorphan, but it was only partially inhibited by the endothelin-converting enzyme specific inhibitor FR901533. These findings suggest that SEP is a novel metalloprotease that possesses a broad substrate specificity and that it may be involved in the metabolism of biologically active peptides intracellulary as well as extracellularly.

Endothelin-converting enzyme-1 (ECE-1) is a type II membrane protein that catalyzes the proteolytic activation of big endothelin-1 to endothelin-1 (ET-1). The subcellular distribution of ECE-1, and hence the exact site of physiological activation of big ET-1, remains controversial. Here, we demonstrate with several complementary methods that the two alternatively spliced bovine ECE-1 isoforms, ECE-1a and ECE-1b, differing only in the first 30 amino acids of their N-terminal cytoplasmic tails, exhibit strikingly distinct intracellular sorting patterns. Bovine ECE-1a, which is responsible for the intracellular cleavage of big ET-1 in endothelial cells, is constitutively recruited into the lysosome, where it is rapidly degraded. In contrast, bovine ECE-1b, the isoform found in cultured smooth muscle cells, is transported to the plasma membrane by a default pathway and functions as an ectoenzyme. Mutational analyses reveal that the N-terminal tip of the cytoplasmic domain of bovine ECE-1a contains novel proline-containing signals that mediate constitutive lysosomal targeting. Analyses of chimeric ECE-1/transferrin receptors demonstrate that the cytoplasmic tail of bovine ECE-1a is sufficient for the lysosomal delivery and rapid degradation. Our results suggest that the distinct intracellular targeting of bovine ECE-1 isoforms may provide new insights into functional aspect of the endothelin system and that the cell permeability of ECE inhibitor compounds should be carefully considered during their pharmacological development.The endothelins are a family of 21-amino acid peptides consisting of three closely related isoforms termed endothelin-1 (ET-1), 1 ET-2, and ET-3 (1, 2). They act on two molecularly distinct subtypes of seven membrane-spanning G protein-coupled receptors, the endothelin A (ET A ) and endothelin B (ET B ) receptors, to mediate a wide variety of biological activities (3, 4). Recent studies with specific endothelin receptor antagonists have illustrated important roles of endothelins in a number of pathological conditions in humans including congestive heart failure, vascular restenosis, and essential hypertension (5-9). Further, recent genetic studies in mice demonstrated that the endothelin system is also required for development of specific neural crest-derived tissues (10 -13).Biologically active endothelins are produced from prepropolypeptides through two steps of proteolytic processing. The approximately 200-residue preproendothelins are first processed by a furin-like processing protease(s) into biologically inactive intermediates termed big endothelins (big ETs). These are then proteolytically cleaved between Trp 21 and Val/Ile 22 to produce active endothelins. This proteolytic conversion is catalyzed by specific endothelin-converting enzymes (ECEs). Two isozymes of ECE, ECE-1 and ECE-2, have been molecularly identified (14 -16). Both ECEs are type II membrane proteins with highly conserved Zn 2ϩ metalloprotease motifs and cleave big ET-1 to produce ET-1 in vitro as well as in transfected cel...

It is our hypothesis that as a consequence of increased oxidative stress, rats develop lung injury with increased cholesterol-derived hydroperoxides and oxysterols in lung after consecutive exposure of the rats to paraquat. To test this we administered 10 mg/kg of paraquat i.p. once or seven times (once a day) to Wistar rats. Rats were killed, and lung tissue was collected 24 h after the last paraquat injection. We found that in response to consecutive paraquat doses, there were significant increases in 7alpha- and 7beta-hydroperoxycholest-5-en-3beta-ol (7alpha-OOH and 7beta-OOH; P=0.01) as well as 7alpha- and 7beta-hydroxycholesterol (7alpha-OH and 7beta-OH; P=0.01), and 7-ketocholesterol (7-keto; P=0.03). In addition, pulmonary hemorrhage, thickening of alveolar septum, and inflammatory cell infiltration of macrophages were observed. This is the first report showing enhanced cholesterol peroxidation and lung injury of rats due to consecutive doses of paraquat.

An accidental atypical hanging with the collar of a sweater is reported. A 67-year-old man was found dead in the sitting position with the collar of his sweater hanging off the brake handle of a motorcycle. Autopsy findings revealed a ligature mark on the surface of the neck; hemorrhages in the sternohyoid muscles; submucosal hemorrhages in the left greater horn of the hyoid bone; a large degree of submucosal petechial hemorrhages in the larynx, oral mucosa, and palpebral conjunctivae; and dark-red liquid blood with little clotting in the heart cavities. The alcohol levels in the blood and urine were 2.84 mg/ml and 3.52 mg/ml, respectively. It was concluded that the man had died from hanging by the sweater, and it was speculated that when he became inebriated, he might have lost consciousness and then fell with the collar of his sweater hanging from the brake handle of the motorcycle.

Hazard identification, risk assesment and risk control and the application of risk mapping at Hospital of the Animal Prof. Soeparwi Universitas Gadjah Mada Purpose: This research was held to analyze the work accident using HIRARC method and the applied of Risk Mapping at the hospital of the animal of Prof. Soeparwi Gadjah Mada University, Yogyakarta.Method: This research used descriptive qualitative research method. The qualitative method used to describe the condition, assess, and to recognize the work accident analysis. The data used was grabbed from Hazard Identification Risk Assessment and Risk Control (HIRARC) method and questionnaire.Results: Hazard identification used HIRARC method at the hospital of the animal of Prof. Soeparwi Gadjah Mada University was about 198. The work hazard commonly includes physical hazard, chemistry, biologist, ergonomics, and psychosocial. The risk assessment which held denoted that there were 61 low risks, 108 medium risks, and 15 high risks. The recommendations of risk restraint that can be given were technician control, administrative, and the use of personal protective equipment (PPE).Conclusion: HIRARC method had been applied at the hospital of animal of Prof. Soeparwi with the result to that grooming unit was high risk work place, assessed with risk mapping. The risk was from animal contact phisically.