Actions of angiotensin peptides on the rabbit pulmonary artery

The presence of the angiotensin AT1A-like receptor subtype in the pulmonary artery and AT1B-like receptor subtype in the pulmonary trunk of the rabbit has been reported in two earlier studies. The present study further investigated these receptor subtypes using five other angiotensins (namely angiotensin II, angiotensin III, angiotensin IV, angiotensin-(1-7) and angiotensin-(4-8)). The direct action of the angiotensins on the rabbit pulmonary arterial and trunk sections and the ability of each angiotensin to further contract or relax preconstricted sections of the pulmonary artery and trunk were studied using the organ bath set-up. The effects of angiotensin III on the 3H overflow from re-uptaken [3H]noradrenaline in the electrically-contracted rabbit pulmonary arterial and trunk sections were also studied. The contractile response of the arterial and trunk section had the following rank order potency: angiotensin II > angiotensin III > angiotensin IV. The contractile response to these angiotensins was greatly reduced or absent in the pulmonary trunk. Angiotensin II further contracted the preconstricted arterial and trunk sections. In contrast, angiotensin III further contracted the preconstricted arterial section but relaxed the preconstricted trunk section. Angiotensin IV similarly relaxed the preconstricted trunk section but had minimum effect on the preconstricted arterial section. Angiotensin-(1-7) and angiotensin-(4-8) had no effect on both sections. The actions of the three angiotensins were inhibited by losartan, an AT1-selective antagonist. Indomethacin, a cyclo-oxygenase inhibitor, inhibited the relaxation caused by angiotensin III and angiotensin IV in the trunk section. The effects of angiotensin III on the electrically preconstricted sections of the pulmonary trunk and artery were not accompanied by any significant changes in 3H overflow. The differential responses produced by angiotensin II and its immediate metabolites via two positionally located and functionally opposing receptor subtypes suggest that the pulmonary trunk and artery is not a passive conduit but an important regulator of blood flow from the heart to the lung.     

Quantitative electron microscopic research on the structure of the myocytes in the atrioventricular node and perinodal myocardium of the rat interatrial septum

A quantitative electron microscopical examination of specialized conducting myocytes of types II and III in the atrioventricular node and working myocytes in perinodal region was performed. The volume fractions of myofibrils, mitochondria, nuclei, sarcoplasmic reticulum, glycogen, atrial granules and "clear" cytoplasm were measured, in addition to the diameters of conducting and working myocytes. These data were compared with those for conducting myocytes of types I, II, and III from sinoatrial region and internodal tracts of the rat heart, and with evidence for atrioventricular node of other animals. Principles of an universal classification of conducting myocytes of the heart are discussed.     

Polymorphism and inheritance of swine small intestinal receptors mediating adhesion of three serological variants of Escherichia coli-producing K88 pilus antigen

Summary. Brush borders, enterocytes, or both preparations obtained from the small intestine of 345 pedigreed pigs, carrying components of seven breeds, were tested by adhesion assay in vitro with 6–32 enteropathogenic Escherichia coli strains, each expressing one of the three K88 pilus antigens, K88ab, K88ac and K88ad. With few exceptions, all pigs were classified as belonging to one of four adhesion phenotypes: I – corresponding to K88ab(-),ac(-),ad(-); II – K88ab(-),ac(+),ad(+); III – K88ab(+),ac(+),ad(-); and IV – K88ab(+),ac(+),ad(+). The non-adhering phenotype I was found to be the most frequent among the pigs tested, with the exception of one commercial herd, and this phenotype seems to be inherited as a recessive trait. The remaining three phenotypes are adhering, or are susceptible to adherence by one K88 variant, K88ad (phenotype II), by two variants, K88ab,ac (phenotype III), or by all three K88 variants, K88ab,ac,ad (phenotype IV). Phenotype II was found to be at low frequency, whereas III and IV occurred with similar frequencies. While the prevailing phenomenon was the bacterial adhesion to all, or none, of the brush borders, some pigs exhibited both adhering and non-adhering brush borders, a mixed adherence phenotype. Preliminary segregation data, obtained from the F1 generation, seem to indicate that phenotypes III and IV correspond to two haplotypes with genes at two or three closely linked loci respectively. An alternative hypothesis is that the phenotypes [II and IV are expressions of alleles at a single locus, each allele specifying a receptor able to bind two or three different serological types of K88 E. coli.     

Fine structure of the elasmobranch renal tubule: neck and proximal segments of the little skate

This is the first in a series of studies that examines the renal tubular ultrastructure of elasmobranch fish. Each subdivision of the neck segment and proximal segment of the renal tubule of the little skate (Raja erinacea) has been investigated using electron microscopy of thin sections and freeze-fracture replicas. Flagellar cells, characterized by long, wavy, flagellar ribbons, were observed in both nephron segments. They were found predominantly in the first subdivision of the neck segment, which suggests that propulsion of the glomerular filtrate is a primary function of this part of the renal tubule. In the non-flagellar cells of the neck segment (subdivisions I and II), there were bundles of microfilaments, a few apical cell projections, and, in subdivision II, numerous autophagosomes. In the proximal segment, the non-flagellar cells varied in size, being low in subdivision I, cuboidal in II, tall columnar in III, and again low in IV. Apical cell projections were low and scattered in subdivisions I and IV and were highest in III where the basolateral plasma membrane was extremely amplified by cytoplasmic projections. Furthermore, in these cells the mitochondria were numerous with an extensive matrix and short cristae. A network of tubules of the endoplasmic reticulum characterized the apical region of the non-flagellar cells in subdivisions I, II, and IV. In the late part of subdivision II and the early part of III, the cells were characterized by numerous coated pits and vesicles, large subluminal vacuoles, and basally located dense bodies, all of which are structures involved in receptor-mediated endocytosis. Freeze-fracture replicas revealed gap junctions restricted to the cells of the first three subdivisions of the proximal segment. The zonulae occludentes were not different in the neck and proximal segments, being composed of several strands, suggesting a moderately leaky paracellular pathway.     

Effect of the time of theophylline administration on the intensity of diuresis and natriuresis in the rat]

The present study originates in two experimental data: circadian variations evidence of water, electrolytes and solutes urinary excretion and theophylline diuretic and salidiuretic effects knowledge; we purpose to evidence theophylline-induced water and sodium renal excretion in rats as modified by the time of drug administration. Theophylline single dose is injected in 100 animals (20 lots of 5 rats) at 8 h, 14 h, 20 h or 2 h and urines are collected during a consecutive to injection hours long period: 8 h-14 h (I), 14 h-20 h (II), 20 h-2 h (III) or 2 h-8 h (IV). Diuresis increases in + 40,4 p. cent (I), in + 123,7 p. cent (II), in + 123,3 p. cent (III) in + 65,4 p. cent (IV). So, natriuresis increases in 39,6 p. cent (I), in 223,2 p. cent (II), in 114,3 p cent (III) and in 109,6 p. cent (IV). These results evidence that theophylline diuretic and natriuretic effects change strongly with injection time, being largest if it is injected at 14 h and slightest if injected at 8 h. Such observations prompt to study if the other pharmacological properties of theophylline, especially at pulmonary level, response also with a time-dependant intensity.     

Polymorphism and inheritance of swine small intestinal receptors mediating adhesion of three serological variants of Escherichia coli-producing K88 pilus antigen

Brush borders, enterocytes, or both preparations obtained from the small intestine of 345 pedigreed pigs, carrying components of seven breeds, were tested by adhesion assay in vitro with 6-32 enteropathogenic Escherichia coli strains, each expressing one of the three K88 pilus antigens, K88ab, K88ac and K88ad. With few exceptions, all pigs were classified as belonging to one of four adhesion phenotypes: I I--corresponding to K88ab(-),ac(-),ad(-); II--K88ab(-),ac(-),ad(+); III--K88ab(+),ac(+),ad(-); and IV--K88ab(+),ac(+),ad(+). The non-adhering phenotype I was found to be the most frequent among the pigs tested, with the exception of one commercial herd, and this phenotype seems to be inherited as a recessive trait. The remaining three phenotypes are adhering, or are susceptible to adherence by one K88 variant, K88ad (phenotype II), by two variants, K88ab, ac (phenotype III), or by all three K88 variants, K88ab,ac,ad (phenotype IV). Phenotype II was found to be at low frequency, whereas III and IV occurred with similar frequencies. While the prevailing phenomenon was the bacterial adhesion to all, or none, of the brush borders, some pigs exhibited both adhering and non-adhering brush borders, a mixed adherence phenotype. Preliminary segregation data, obtained from the F1 generation, seem to indicate that phenotypes III and IV correspond to two haplotypes with genes at two or three closely linked loci respectively. An alternative hypothesis is that the phenotypes III and IV are expressions of alleles at a single locus, each allele specifying a receptor able to bind two or three different serological types of K88 E. coli.     

Morphology and structural organization of Haller's organ during postembryonic development ofArgas (Persicargas) walkerae (Ixodoidea: Argasidae)

Scanning-electron-microscopic investigations of Haller's organ in larvae, nymphs I, II, III and IV, and male and female adultArgas (Persicargas) walkerae ticks showed that morphology and structural organization change during postembryonic development. Stage-dependent differences existed regarding setal numbers of the anterior pit as well as formation and reticulation of cuticular projections in the capsule cavity. The anterior pit increased in size in the course of postembryonic development. It contained only seven setae in larvae, one conical, setiform and grooved seta each as well as two porose and fine setae. Nymphs I, II, III and IV and adult ticks had equal numbers of setae; however, one additional unilaterally serrate and grooved seta each were present. Setal length increased continuously during postembryonic development and attained maximum values in adult ticks. The capsule consisted of roof and cavity and was located distinctly lateral in larvae, slightly lateral in nymphs I and II, and in all other stages directly on the longitudinal axis of tarsus. The capsule roof showed a reticular structure. The slit-like main aperture was located peripherally and arranged transversally to the longitudinal axis of tarsus I in larvae. Nymphs and adult ticks had a central, circular main aperture. Stage-dependent cuticular projections of varying form protruded into the capsule cavity. Larvae had only single, free-standing projections which ramified slightly and communicated with each other. Projections were more heavily reticulated in nymphs I and II. In nymphs III and IV as well as male and female adult ticks, a long centrally situated tube of reticular appearance was seen, which was supported by a large number of radially organized and interlocking pillars and communicated with the capsule roof. In all tick stages there were always four porose setae present, arranged on the capsule floor.     

Genetic classification of riboflavin-dependent mutants of Pichia guilliermondii yeasts]

114 riboflavinless mutants were selected from the genetic line of Pichia guilliermondii yeast. By means of accumulation test the mutants were divided into five biochemical groups. In genetic experiments seven complementation classes were found among 106 mutants. The strains of the I biochemical group, accumulating no specific products, corresponded to complementation class rib1; II group, accumulating 2,4,5-triaminopyrimidine - to the class rib2; III group, accumulating 2,6-dihydroxy-4-ribitylaminopyrimidine - to the class rib3; the mutants of the IV group, accumulating 2,6-dihydroxy-5-amino-4-ribitylaminopyrimidine, were divided into three complementation classes rib4, rib5 and rib6; the mutants of the V group, acculumating 6,7-dimethyl-8-ribityllumazine, corresponded to the class rib7. Two mutants of the IV biochemical group within complementation classes rib4 and rib5 were detected could not grow in the medium with diacetyl without riboflavin. Intragenic complementation was found within classes rib6 and rib7. No linkage between mutations of different complementation classes was detected.     

The ratio of oxidative phosphorylation complexes I-V in bovine heart mitochondria and the composition of respiratory chain supercomplexes

The ratios of the oxidative phosphorylation complexes NADH:ubiquinone reductase (complex I), succinate:ubiquinone reductase (complex II), ubiquinol:cytochrome c reductase (complex III), cytochrome c oxidase (complex IV), and F1F0-ATP synthase (complex V) from bovine heart mitochondria were determined by applying three novel and independent approaches that gave consistent results: 1) a spectrophotometric-enzymatic assay making use of differential solubilization of complexes II and III and parallel assays of spectra and catalytic activities in the samples before and after ultracentrifugation were used for the determination of the ratios of complexes II, III, and IV; 2) an electrophoretic-densitometric approach using two-dimensional electrophoresis (blue native-polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis) and Coomassie blue-staining indices of subunits of complexes was used for determining the ratios of complexes I, III, IV, and V; and 3) two electrophoretic-densitometric approaches that are independent of the use of staining indices were used for determining the ratio of complexes I and III. For complexes I, II, III, IV, and V in bovine heart mitochondria, a ratio 1.1 +/- 0.2:1.3 +/- 0.1:3:6.7 +/- 0.8:3.5 +/- 0.2 was determined.     

SEM studies on the early larval development of Triops cancriformis (Bosc)(Crustacea: Branchiopoda, Notostraca)

We investigated early larval development in the notostracan Triops cancriformis (Bosc, 1801–1802) raised from dried cysts under laboratory conditions. We document the five earliest stages using scanning electron microscopy. The stage I larva is a typical nauplius, lecithotropic and without trunk limbs. The stage II larva is feeding and has trunk limb precursors and a larger carapace. Stage III larvae have larger trunk limbs and a more adult shape. Stage IV larvae have well developed trunk limbs, and stage V larvae show atrophy of the antennae. We describe the ontogeny of selected features such as trunk limbs and carapace, discuss ontogeny and homologization of head appendages, follow the development of the feeding mechanism, and discuss trunk limb ontogeny.     

Secondary heart field contributes myocardium and smooth muscle to the arterial pole of the developing heart

The arterial pole of the heart is the region where the ventricular myocardium continues as the vascular smooth muscle tunics of the aorta and pulmonary trunk. It has been shown that the arterial pole myocardium derives from the secondary heart field and the smooth muscle tunic of the aorta and pulmonary trunk derives from neural crest. However, this neural crest-derived smooth muscle does not extend to the arterial pole myocardium leaving a region at the base of the aorta and pulmonary trunk that is invested by vascular smooth muscle of unknown origin. Using tissue marking and vascular smooth muscle markers, we show that the secondary heart field, in addition to providing myocardium to the cardiac outflow tract, also generates prospective smooth muscle that forms the proximal walls of the aorta and pulmonary trunk. As a result, there are two seams in the arterial pole: first, the myocardial junction with secondary heart field-derived smooth muscle; second, the secondary heart field-derived smooth muscle with the neural crest-derived smooth muscle. Both of these seams are points where aortic dissection frequently occurs in Marfan's and other syndromes.     

Adrenergic neurons and short proprioceptive feedback loops involved in the integration of cardiac function in the rat

Summary Serial cryostat and paraffin-embedded sections through the atrioventricular junction of the rat heart were studied at the light-microscopic level after indirect immunohistochemical staining (tyrosine hydroxylase, neuropeptide Y, C-terminal flanking peptide of neuropeptide Y immunoreactivities) or silver impregnation. The distribution of these immunoreactivities in the Hissian ganglion (Moravec and Moravec 1984) as well as the relationships of the Hissian ganglion cells with the surrounding structures have been studied to assess its function. The results suggest that the Hissian ganglion is composed of large multipolar neurons displaying both tyrosine hydroxylase (TH) and related peptide (neuropeptide Y, C-terminal flanking peptide of neuropeptide Y) immunoreactivities. The dendritic projections of these adrenergic cells penetrate the reticular portion of the atrioventricular node and the upper segments of the interventricular septum where they constitute sensory-like corpuscles. The hypothesis that the adrenergic neurons of the atrioventricular junction are involved in short proprioceptive feedback loops necessary for beat-to-beat modulation of cardiac excitability and intracardiac conduction can thus be suggested.     

Rib cage deformities alter respiratory muscle action and chest wall function in patients with severe osteogenesis imperfecta

Background

Osteogenesis imperfecta (OI) is an inherited connective tissue disorder characterized by bone fragility, multiple fractures and significant chest wall deformities. Cardiopulmonary insufficiency is the leading cause of death in these patients.

Methods

Seven patients with severe OI type III, 15 with moderate OI type IV and 26 healthy subjects were studied. In addition to standard spirometry, rib cage geometry, breathing pattern and regional chest wall volume changes at rest in seated and supine position were assessed by opto-electronic plethysmography to investigate if structural modifications of the rib cage in OI have consequences on ventilatory pattern. One-way or two-way analysis of variance was performed to compare the results between the three groups and the two postures.

Results

Both OI type III and IV patients showed reduced FVC and FEV₁ compared to predicted values, on condition that updated reference equations are considered. In both positions, ventilation was lower in OI patients than control because of lower tidal volume (p<0.01). In contrast to OI type IV patients, whose chest wall geometry and function was normal, OI type III patients were characterized by reduced (p<0.01) angle at the sternum (pectus carinatum), paradoxical inspiratory inward motion of the pulmonary rib cage, significant thoraco-abdominal asynchronies and rib cage distortions in supine position (p<0.001).

Conclusions

In conclusion, the restrictive respiratory pattern of Osteogenesis Imperfecta is closely related to the severity of the disease and to the sternal deformities. Pectus carinatum characterizes OI type III patients and alters respiratory muscles coordination, leading to chest wall and rib cage distortions and an inefficient ventilator pattern. OI type IV is characterized by lower alterations in the respiratory function. These findings suggest that functional assessment and treatment of OI should be differentiated in these two forms of the disease.     

Effect of ruthenium complexes on the activities of succinate dehydrogenase and cytochrome oxidase

In this article, we report the effects of acute administration of ruthenium complexes, trans-[RuCl(2)(nic)(4)] (nic=3-pyridinecarboxylic acid) 180.7 micromol/kg (complex I), trans-[RuCl(2)(i-nic)(4)] (i-nic=4-pyridinecarboxylic acid) 13.6 micromol/kg (complex II), trans-[RuCl(2)(dinic)(4)] (dinic=3,5-pyridinedicarboxylic acid) 180.7 micromol/kg (complex III) and trans-[RuCl(2)(i-dinic)(4)]Cl (i-dinic=3,4-pyridinedicarboxylic acid) 180.7 micromol/kg (complex IV) on succinate dehydrogenase (SDH) and cytochrome oxidase (COX) activities in brain (hippocampus, striatum and cerebral cortex), heart, skeletal muscle, liver and kidney of rats. Our results showed that complex I inhibited SDH activity in hippocampus, cerebral cortex, heart and liver; and inhibited COX in heart and kidney. Complex II inhibited SDH in heart and hippocampus; COX was inhibited in hippocampus, heart, liver and kidney. SDH activity was inhibited by complex III in heart, muscle, liver and kidney. However, COX activity was increased in hippocampus, striatum, cerebral cortex and kidney. Complex IV inhibited SDH activity in muscle and liver; COX activity was inhibited in kidney and increased in hippocampus, striatum and cerebral cortex. In a general manner, the complexes tested in this work decrease the activities of SDH and COX in heart, skeletal muscle, liver and kidney. In brain, complexes I and II were shown to be inhibitors and complexes III and IV activators of these enzymes. In vitro studies showed that the ruthenium complexes III and IV did not alter COX activity in kidney, but activated the enzyme in hippocampus, striatum and cerebral cortex, suggesting that these complexes present a direct action on COX in brain.     

Immunological studies on cytochrome c oxidase: arrangements of protein subunits in the solubilized and membrane-bound enzyme.

Seven protein subunits of cytochrome c oxidase from bovine heart were isolated by gel filtration in the presence of sodium dodecyl sulphate (subunits I, II and III) and guanidine hydrochloride (subunits V, VI and VII), and ion-exchange chromatography in 6 M urea (subunit IV) after the enzyme had been dissociated in 6 M guanidine hydrochloride. When analysed by highly cross-linked sodium dodecyl sulphate/polyacrylamide gel electrophoresis in the presence of urea, the apparent molecular weights were = I, 36700; II, 24300; III, 20400; IV, 17300; V, 12300; VI, 8700: and VII, 5100. Monospecific rabbit antisera were obtained against subunits I, IV, V, VI and VII and a mixture of subunits II and III. These subunit-specific antisera with the exception of anti-I serum all cross-reacted with the detergent-solubilized native oxidase. Enzymatic studies on purified oxidase indicated that immunoglobulins against subunits II + III, IV, V, VI and VII respectively caused 25, 65, 20, 30 and 25% inhibition while anti-I immunoglobulin did not inhibit the activity. The subunit-specific antisera were used to examine the arrangements of the subunits in the membrane. Enzymatic studies using bovine heart mitochondria and rat liver mitochondrial digitonin particles showed that anti-(II + III) serum, anti-V serum and anti-VII serum all inhibited the oxidase activity while the other antisera did not. On the other hand, results of using 125I-labelled immunoglobulins showed that anti-IV, anti-V and anti-VII sera were bound to the surface of inverted vesicles (matrix side) while all other antisera were not. These results indicate that cytochrome oxidase subunits II and III are situated on the outer surface, and subunit IV is exclusively on the matrix surface while subunits V and VII are exposed on both surfaces of the mitochondrial membrane. Subunits I and VI are buried within the membrane, not exposed on either side.     

Resolving the Conflicts Between Biodiversity Conservation and Socioeconomic Development in China: Fuzzy Clustering Approach

Resolving the conflicts between biodiversity conservation and socioeconomic development is a global pursuit for the long-run prospects of the human species. Based on Wenchuan County, a typical county in southwestern China, a group of 20 indicators quantifying regional biodiversity and socioeconomic development was established to classify and evaluate the county area spatially. A fuzzy c-means clustering (FCM) algorithm was used as the classification method. Three indices including BD, DL and DR characterizing the value of biodiversity, the level and rate of socioeconomic development of the delineated regions were formulated. The results indicated that Wenchuan County was optimally classified into 4 types of regions (region I to IV). The area percentages of the regions vary widely from 4.3 to 65.7%. The sequences of the regions on biodiversity, socioeconomic development level, and socioeconomic development rate were, respectively, IV > II > III > I, I > III > II > IV and III >I >II >IV. The spatial strategy on coordinating biodiversity conservation and regional development is to develop mainly from the east(I, II, III) and to conserve mainly in the west(IV). Eco-industry, such as eco-tourism and eco-agriculture, need to be emphasized in the process of regional development. The quantitative methods used here may have a wide applicability.     

Recharacterization of Pseudomonas fulva Iizuka and Komagata 1963, and proposals of Pseudomonas parafulva sp. nov. and Pseudomonas cremoricolorata sp. nov

Seven Pseudomonas fulva strains obtained from culture collections were taxonomically studied. The seven strains were separated into three clusters (Clusters I to III) on the basis of 16S rRNA gene sequences, and located phylogenetically in the genus Pseudomonas sensu stricto. Further, the strains were classified into 4 groups (Groups I to IV) on the basis of DNA-DNA similarity. As a result, Cluster I was split into Groups I and II. Group I included the type strain of P. fulva and two strains, and levels of DNA-DNA similarity ranged from 88 to 100% among the strains. Group II contained two strains, and the level between the two strains ranged from 91 to 100%. Group III consisted of one strain. Group IV included one strain, and this strain showed a high level of DNA-DNA similarity with the type strain of Pseudomonas straminea NRIC 0164(T). Clusters II and III corresponded to Groups III and IV, respectively. The four groups were separated from one another and from related Pseudomonas species at the level from 3 to 45% of DNA-DNA similarity. The strains of Groups I, II, and III had ubiquinone 9 as the major quinone. According to numerical analysis by the use of 133 phenotypic characteristics, the seven P. fulva strains were split into four phenons (Phenons I to IV). The groups by DNA-DNA similarity corresponded well with the phenons produced by numerical taxonomy, and differential characteristics were recognized. Consequently, Group I was regarded as P. fulva because the type strain (NRIC 0180(T)) of this species was included in this group. Strains in Group II were identified as a new species, Pseudomonas parafulva sp. nov., and the type strain is AJ 2129 (=IFO 16636=JCM 11244=NRIC 0501). NRIC 0181 in Group III was identified as a new species, Pseudomonas cremoricolorata sp. nov., and the type strain is NRIC 0181 (=IFO 16634=JCM 11246). NRIC 0182 in Group IV was identified as P. straminea on the basis of the high level of DNA-DNA similarity with the type strain of this species.     

Tissue distribution of mRNAs encoding muscarinic acetylcholine receptor subtypes

The tissue distribution of the mRNAs encoding muscarinic acetylcholine receptors (mAChRs) I, II, III and IV has been investigated by blot hybridization analysis with specific probes. This study indicates that exocrine glands contain both mAChR I and III mRNAs, whereas smooth muscles contain both mAChR II and III mRNAs. All four mAChR mRNAs are present in cerebrum, whereas only mAChR II mRNA is found in heart.     

Subunit arrangement in beef heart complex III

Beef heart mitochondrial complex III was separated into 12 polypeptide bands representing 11 different subunits by using the electrophoresis conditions described by Sch?gger et al. [(1986) Methods Enzymol. 126, 224-237]. Eight of the 12 polypeptide bands were identified from their NH2-terminal sequences as obtained by electroblotting directly from the NaDodSO4-polyacrylamide gel onto a solid support. The topology of the subunits in complex III was explored by three different approaches. (1) Protease digestion experiments of submitochrondrial particles in the presence and absence of detergent showed that subunits II and VI are on the M side of the inner membrane and subunits V and XI on the C side. (2) Labeling experiments with the membrane-intercalated probes [125I]TID and arylazidoPE indicated that cytochrome b is the predominant bilayer embedded subunit of complex III, while the non-heme iron protein appears to be peripherally located. (3) Cross-linking studies with carbodiimides and homobifunctional cleavable reagents demonstrated that near-neighbor pairs include subunits I+II, II+VI, III+VI, IV+V, V+X, and reagents demonstrated that near-neighbor pairs include subunits I+II, II+VI, III+VI, IV+V, V+X, and VI+VII. The cytochrome c binding site was found to include subunits IV, VIII, and X. The combined data are used to provide an updated model for the topology of beef heart complex III.     

Evaluation of the hormonal function and histological features of heterotopic isogenic ovarian transplantation in rats

The purpose of the study was to determine the feasibility of preserving ovarian function after heterotopic transplantation by means of microvascular anastomosis of the transplanted vascular pedicles to a set of preselected vessels. Six groups of 10 Sprague-Dawley inbred rats were used in this study. Group I underwent bilateral ovariectomy operation and served as the ovariectomy control. Group II underwent bilateral ovariectomy followed by heterotopic isogenic ovarian implantation. Group III underwent bilateral ovariectomy and isogenic heterotopic ovarian transplantation by means of microvascular anastomosis. Group IV served as the laparotomy sham-operated control. Group V served as the ovarian donor for group II. Group VI served as the donor of the ovarian-kidney vascular pedicle complex for group III. Postoperative ovarian estradiol levels were measured, and histological characteristics were elucidated in groups I, II, III, and IV. The results demonstrated that the estradiol level of the transplantation group was comparable to that of the sham operation group and was significantly higher than that of the implantation group. Histologically normal ovarian architecture was observed in the sham group (IV) and also in the transplantation group (III). Altered architecture was observed in the implantation group (II). These findings indicate that extraabdominal heterotopic ovarian transplantation with microvascular anastomosis led to normal ovarian hormonal function and was effective in preserving oocyte production capacity.