Progressive intraventricular drop of early diastolic flow velocity reflects impaired active ventricular diastolic function in hypertensive heart disease: comparative study between early diastolic and atrial contraction phases

Left ventricular (LV) diastolic function in the early diastolic phase includes both active and passive processes, but in the atrial contraction phase it includes only passive processes. To elucidate the relation between the intraventricular dispersion of the flow velocity in diastole and LV diastolic process, 31 normal volunteers and 12 patients with hypertensive heart disease were studied. In these subjects the flow velocity pattern at the mitral tip was recorded simultaneously with regional flow velocity patterns 1, 2, or 3 cm from the mitral tip toward the apex, respectively, with multigate pulsed Doppler echocardiography from the apical long-axis view with the guidance of Doppler color-flow imaging. Although the ratio of regional peak flow velocity/mitral peak flow velocity in the atrial contraction phase decreased from the mitral tip to the apex to the same degree in the normal volunteers and patients with hypertensive heart disease, there was a significant difference in the intraventricular dispersion of the early diastolic flow velocity between the two groups. These results suggest that the progressive intraventricular drop of the flow velocity in the early diastolic phase in patients with hypertensive heart disease may reflect the impairment of active rather than passive LV diastolic function.

Differences in dispersion of monkey optic nerve fibers according to their terminal layers in the lateral geniculate nucleus

Dispersion of retinogeniculate fibers in the monkey optic nerve was investigated in relation to their terminal layers in the lateral geniculate nucleus (LGN) using a retrograde axonal tracer (wheat germ agglutinin conjugated to horseradish peroxidase, WGA-HRP). Dispersion of fibers projecting to the parvocellular layer of the LGN (LGNp) is clearly less extensive compared with that of fibers projecting to the magnocellular layer of the LGN (LGNm) in the most distal part of the optic nerve. The occupation rate of retrogradely labeled fibers projecting from the periphery of the nasal retina to the LGNp increases only 1.2 times in the initial part of the nerve. In contrast, the occupation rate increases up to 1.6 times for labeled fibers projecting from a similar part of the nasal peripheral retina to the LGNm in the same part of the optic nerve. The morphological features of the labeled ganglion cells indicate that these fibers arise from P beta and P alpha ganglion cells, respectively.

Organization of the sources of reticulospinal projections in the chicken by means of a confocal laser scanning microscope

To investigate the manner of reticulospinal projections in chickens, two different fluorescent dyes (Fast-Blue and Diamidino-Yellow) were injected into the lumbar and sacral segments. Results showed that the main projections to the spinal segments are clearly different for the pons and medulla. The main source of the medulospinal projections was in the ventral reticular formation, and the projections from the dorsal reticular formation were sporadic. On the other hand, the main pontine projections arose from the dorsolateral tegmentum and they projected to the sacral segments. In contrast, projections to the lumbar segments were somewhat more dominant in the ventromedial tegmentum than in the dorsolateral tegmentum. Double projection neurons were observed in the ventrolateral reticular formation and dorsolateral tegmentum where there were many cells of origin of the spinal descending projections. The reticulospinal projections manner of birds was organized dorsoventrally, and it was comparable with that of mammals.

Cell counts in peripheral blood and bone marrow of male C.B-17 scid/scid mice

Blood cell and bone marrow cell counts were carried out for male C.B-17 scid/scid (SCID) mice aged 3, 6, 9, 18 and 26 weeks and the values were compared with those in C.B-17 +/+ (C.B-17) mice. In the peripheral blood, SCID mice had markedly low numbers of leucocytes and lymphocytes throughout the study. In the bone marrow, SCID mice had relatively low levels of erythroblasts at an early age, low levels of lymphocytes and plasma cells were absent.

Intraventricular dispersion of early diastolic filling: a new marker of left ventricular diastolic dysfunction

Mitral flow velocity patterns are frequently "normalized" by the alteration in the loading condition even in the presence of left ventricular (LV) diastolic dysfunction. In addition, a simple index, the ratio of mitral peak early diastolic flow velocity to mitral peak flow velocity at atrial contraction, is not obtainable in patients with atrial fibrillation (Af). Thus these limitations hamper the value of analyzing the mitral flow velocity pattern in the assessment of abnormal LV diastolic characteristics. This study was designed to elucidate the hypothesis that peak early diastolic flow velocity decreases progressively from the base to the apex in patients with LV diastolic dysfunction. Regional diastolic flow velocity patterns at 1, 2, or 3 cm from the mitral tip toward the apex were simultaneously recorded with the mitral flow velocity pattern by using multigate pulsed Doppler echocardiography in 42 subjects with normal LV function (31 normal volunteers and 11 patients with Af only), 17 patients with hypertensive heart disease, and 22 patients with dilated cardiomyopathy. In the normal subjects early diastolic flow velocity at the mitral tip was maintained at the positions 1 to 3 cm away from the tip into the LV cavity. In contrast, regional peak early diastolic flow velocity progressively decreased toward the apex in patients with hypertensive heart disease and dilated cardiomyopathy. These findings were observed even in patients with a normalized mitral flow velocity pattern or those with Af. Thus the assessment of the intraventricular decrease in peak early diastolic flow velocity may be useful in detecting LV diastolic dysfunction, particularly in patients with Af or a "normalized" mitral flow velocity pattern.

Digital subtraction high-frame-rate echocardiography in detecting delayed onset of regional left ventricular relaxation in ischemic heart disease

BACKGROUND

Because left ventricular (LV) diastolic function is impaired before systolic function in patients with ischemic heart disease and because ischemic heart disease is constituted of regional rather than global abnormalities of the left ventricle, measures of LV regional diastolic dysfunction, if possible, should provide the most sensitive assessment of the coronary involved region. The objectives of this study are to clarify whether high-frame-rate two-dimensional echocardiography, combined with digital subtraction image processing, may be used to visualize regional LV relaxation abnormalities in patients with ischemic heart disease and to clarify whether this technique provides a measure for the noninvasive assessment of the coronary involved region.

METHOD AND RESULTS

In 30 normal subjects and 59 patients with ischemic heart disease, two-dimensional echocardiograms obtained at a rate of 60 frames per second were provided on line for digital subtraction analysis, with which digitized images were continuously subtracted on a frame-by-frame basis. The subtracted images were analyzed to determine the onset of the segmental outward motion of the LV wall in early diastole in each of 16 segments per subject. Regional relaxation index, defined as the interval from the second heart sound to the onset of outward wall motion, was significantly prolonged in the coronary involved segments compared with the normal segments (36.3 +/- 18.0 versus 101.2 +/- 34.0 ms, P < .01). The prolongation in the regional relaxation index was observed even in the coronary involved segments without reduction in systolic wall motion. When a cutoff level of 50.0 ms was used, coronary involved segments could be distinguished from normal or border segments with a sensitivity of 92% and a specificity of 81%.

CONCLUSIONS

Digital subtraction high-frame-rate echocardiography may be used to visualize regional LV relaxation abnormalities in patients with ischemic heart disease. The time interval from the second heart sound to the onset of the segmental outward motion of the LV wall (regional relaxation index) obtained with this technique provides a noninvasive and accurate measure for assessing coronary involved regions.

Doppler echocardiographic pulmonary venous flow-velocity pattern for assessment of the hemodynamic profile in acute congestive heart failure

The hemodynamic profile of congestive heart failure (CHF) is best described in terms of its two primary sets of hemodynamic parameters, that is, left atrial pressure and cardiac output, each of which has a specific and independently variable hemodynamic cause. To assess whether analysis of the mitral and/or pulmonary venous flow-velocity patterns provides valuable information in the noninvasive assessment of the hemodynamic profile of CHF, these patterns were obtained by using the transthoracic approach in 18 patients with acute CHF with simultaneous measurements of catheter-derived mean pulmonary capillary wedge pressure and thermodilution cardiac index. Measurements were repeated on two occasions in each case: at the acute stage of CHF and 1 to 5 days after treatment. Peak diastolic pulmonary venous forward flow velocity was higher, the ratio of pulmonary venous systolic to diastolic peak forward flow velocity was lower, and the ratio of mitral early diastolic to late diastolic flow velocity was greater in patients with higher mean pulmonary capillary wedge pressure (r = 0.80, n = 36, p < 0.01; r = -0.69, n = 36, p < 0.01; r = 0.71, n = 36, p < 0.01). Peak systolic pulmonary venous forward flow velocity and time-velocity integral of the systolic pulmonary venous flow wave were greater in patients with larger cardiac index (r = 0.80, n = 36, p < 0.01; r = 0.62, n = 36, p < 0.01). In conclusion, two primary sets of hemodynamic parameters, that is, left atrial pressure and cardiac output, can be estimated with Doppler pulmonary venous flow parameters in patients with acute CHF.

Transthoracic Doppler echocardiographic measurements of pulmonary venous flow velocity patterns: comparison with transesophageal measurements

Recently, we and other groups showed that analysis of transthoracic pulmonary venous flow velocity patterns is useful in the estimation of left ventricular diastolic function and left atrial pressure; however, it is unclear whether transthoracic tracings, in contrast to transesophageal tracings, provide reliable quantitation of the abnormal pulmonary venous flow characteristics in patients with and without cardiac disorders. This study was attempted to validate transthoracic pulmonary venous flow measurements by comparing them with transesophageal measurements in eight normal volunteers and 17 patients with a variety of cardiac disorders. Transesophageal and transthoracic measurements of peak diastolic forward flow velocity, the ratio of peak systolic/diastolic forward flow velocities, and the peak reversal flow velocity at atrial contraction sampled in the right upper pulmonary vein showed good correspondence to each other. The flow velocities were higher in the right upper pulmonary vein than in the left upper pulmonary vein. Narrower spectral flow velocity patterns with higher velocities were obtained 1 to 2 cm distal to the orifice in the pulmonary vein than at the orifice. Thus transthoracic measurements of the pulmonary venous flow velocity pattern are feasible and accurate in patients and may be used to assess left ventricular function and hemodynamics as a substitute for transesophageal measurements.

Validation of transthoracic myocardial ultrasonic tissue characterization: comparison of transthoracic and open-chest measurements of integrated backscatter

To investigate whether myocardial integrated backscatter (IB) can be measured through the chest wall, myocardial IB parameters were measured in five adult mongrel dogs with a newly developed IB imaging system capable of measurements of myocardial IB relative to backscatter from the blood. There was no significant difference in the calibrated myocardial IB between the closed chest and the open chest conditions either in the septum or in the posterior wall if a 2.5- or 3.5-MHz frequency transducer was used. There was no significant difference in the magnitude of cyclic variation in IB between the closed chest and the open chest conditions independent of the frequency of the transducer used. These data suggest that we can accurately measure not only the magnitude of cyclic variation in IB but also the calibrated myocardial IB through the chest wall with a 2.5- or 3.5-MHz frequency transducer. Such data may validate measurements of myocardial IB parameters through the chest wall even in humans.

Noninvasive assessment of left ventricular relaxation using continuous-wave Doppler aortic regurgitant velocity curve. Its comparative value to the mitral regurgitation method

BACKGROUND

The most established parameters of left ventricular (LV) relaxation are peak negative value of the first derivative of LV pressure (-dP/dtmax) and the time constant of isovolumic LV pressure fall. The instantaneous pressure gradient between the aorta and the LV during diastole can be calculated from the continuous-wave Doppler aortic regurgitant velocity spectrum. Because the fluctuation of aortic pressure during LV isovolumic relaxation is negligibly minor and because LV minimal pressure is negligibly low, LV pressure during the isovolumic relaxation period may be derived from the continuous-wave Doppler aortic regurgitant velocity spectrum. This study was designed to clarify whether analysis of continuous-wave Doppler aortic regurgitation recording provides accurate measures of LV relaxation over a wide range of LV function and to determine comparative values of aortic and mitral regurgitation methods in the assessment of LV relaxation.

METHODS AND RESULTS

In eight mongrel dogs with acute ischemic LV dysfunction, the continuous-wave Doppler aortic regurgitant velocity spectrum was recorded simultaneously with high-fidelity LV and aortic pressures, while the continuous-wave Doppler mitral regurgitant velocity spectrum was recorded simultaneously with high-fidelity left atrial and LV pressures. The aortic regurgitant velocity spectrum was provided for the determination of Doppler-derived mean rate of LV pressure fall in 20 ms after the onset of aortic regurgitation (delta P/delta t-AR) and the time interval from the onset of aortic regurgitation to the point at (1-1/e)1/2 of the maximal aortic regurgitant velocity as an estimate of the time constant. The mitral regurgitant velocity spectrum was provided for Doppler-derived mean rate of LV pressure fall in 20 ms after the point of -dP/dtmax (delta P/delta t-MR) and the time interval from the point of -dP/dtmax to the point with mitral regurgitant velocity of (1/e)1/2 of the mitral regurgitant velocity at the point of -dP/dtmax as an estimate of the time constant. delta P/delta t-AR and delta P/delta t-MR correlated well with catheter-derived -dP/dtmax (r = .92, r = .98, P < .01, respectively). The time constant derived from aortic and mitral regurgitant velocity spectra (tau-AR and tau-MR) also correlated well with catheter-derived time constant (r = .84, r = .76, P < .01, respectively). However, a mean difference of the catheter-derived time constant minus tau-MR was larger than tau-AR (29 +/- 30 versus 4 +/- 17 ms, P < .01, presented as mean +/- 2 SD).

CONCLUSIONS

LV relaxation can be assessed from the continuous-wave Doppler aortic regurgitant velocity spectrum. The aortic regurgitation method provides an even more accurate estimate of the time constant compared with the mitral regurgitation method, particularly in the presence of LV dysfunction.

Abnormal coronary flow dynamics at rest and during tachycardia associated with impaired left ventricular relaxation in humans: implication for tachycardia-induced myocardial ischemia

OBJECTIVES

This study attempted to clarify the effect of ventricular relaxation abnormalities on coronary flow dynamics at rest and during tachycardia in humans.

BACKGROUND

Ventricular relaxation abnormality has been demonstrated in animals to have an adverse impact on early diastolic coronary flow dynamics. However, this relation has not been established in humans. Even if the adverse effect were latent at rest, it might become evident during tachycardia because tachycardia reduces coronary flow reserve and facilitates the production of myocardial ischemia.

METHODS

Doppler phasic left coronary flow velocity pattern was obtained at rest and during tachycardia in 23 patients without coronary stenosis. The time constant of left ventricular isovolumic pressure (tau) was used to assess ventricular relaxation.

RESULTS

The time to peak flow velocity of the diastolic coronary flow wave was longer, and the fraction of the first third of diastolic coronary flow was smaller, in patients with a longer tau (r = 0.58, p < 0.01; r = -0.44, p < 0.05), indicating a close relation between early diastolic coronary flow dynamics and ventricular relaxation. Although rapid atrial pacing yielded an increase in the coronary flow velocity integral per minute in all patients, diastolic coronary flow velocity integral per minute increased in 9 patients with a normal (< or = 40 ms) tau at rest but decreased in 14 patients with a longer (> 40 ms) tau at rest.

CONCLUSIONS

Impaired left ventricular relaxation was associated with decreased coronary flow in early diastole at rest and decreased coronary flow throughout diastole during tachycardia in patients without coronary stenosis. These findings may provide more insight into the mechanism of tachycardia-induced subendocardial ischemia in patients with impaired ventricular relaxation but without concomitant coronary stenosis.

Effect of successful angioplasty following thrombolysis on infarct size and left ventricular function

The role of the angioplasty following thrombolysis in acute myocardial infarction has been discussed in several studies, however the effect of successful angioplasty on infarct size and left ventricular function has not been properly evaluated. Successful reperfusion was achieved in 79 out of 104 patients with primary anterior acute myocardial infarction. These patients were classified as follows, according to the type of intervention during the acute phase: 50 patients in which thrombolysis was successful (the thrombolysis group); 12 patients who underwent successful immediate angioplasty following successful thrombolysis (the immediate angioplasty group); and 17 patients in which rescue angioplasty was successful (the rescue angioplasty group). The 25 patients whose infarct-related vessels were not reperfused after intervention were classified as the non-reperfused group. Infarct size, evaluated as defect volume by T1-201 SPECT, 1 month after the onset, was 840 +/- 154 units (mean +/- S.D.) in the immediate angioplasty group and was similar to that in the thrombolysis group (948 +/- 88 units), but significantly smaller than in the non-reperfused group (1759 +/- 108 units). There were no significant differences in left ventricular function in the immediate angioplasty group and the thrombolysis group. Successful rescue angioplasty did not have any beneficial effect on left ventricular functions or infarct size, when compared with the failed thrombolytic group (1105 +/- 169 units vs. 1617 +/- 169 units). End-diastolic volume (52 +/- 3 ml/m2) in the successful rescue angioplasty group, however, was significantly smaller than in the failed thrombolysis group (67 +/- 3 ml/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Transthoracic Doppler assessment of pattern of left ventricular dysfunction in hypertensive heart disease: combined analysis of mitral and pulmonary venous flow velocity patterns

Although mitral flow velocity pattern changes with the progression of left ventricular (LV) diastolic dysfunction, it lacks predictive value in individual patients because of pseudonormalization in the presence of congestive heart failure and many physiologic and pathologic contributors to the mitral flow velocity pattern. To determine whether analysis of pulmonary venous flow velocity patterns complements the information obtainable from the mitral flow velocity patterns in the evaluation of patterns of LV dysfunction of hypertensive heart disease in individual patients, the ratio of the peak early diastolic filling velocity/peak filling velocity at atrial contraction (E/A ratio) in the mitral flow velocity pattern and the ratio of the peak systolic forward flow velocity (S)/peak diastolic forward flow velocity (D) (S/D ratio) in the pulmonary venous flow velocity pattern by the transthoracic approach were determined in 107 hypertensive patients with and without congestive heart failure. Age-related normal values of the E/A and S/D ratios were determined in 61 normal subjects and used to judge the normality or abnormality of the patterns. Results of the study indicate that (1) although an increased mitral E/A ratio is strongly indicative of heart failure with normal LV systolic function, the mitral E/A ratio is frequently within the normal range in hypertensive patients with heart failure; (2) association of decreased pulmonary venous S/D ratios with a normal mitral flow velocity pattern indicates the presence of heart failure as a result of LV systolic dysfunction that is usually observed at the most advanced pattern of LV dysfunction; (3) mild LV diastolic dysfunction is likely to exist in patients with normal E/A ratios if the pulmonary venous S/D ratio is higher than normal value; (4) predictive accuracy in the detection of LV systolic and diastolic dysfunction would be improved if both mitral and pulmonary venous flow velocity patterns rather than the mitral flow velocity pattern alone were analyzed. In conclusion, analysis of pulmonary venous flow velocity recordings improves accuracy and reliability of the Doppler assessment of LV systolic and diastolic dysfunction, particularly in individual hypertensive patients with normal mitral flow velocity patterns.

Retinogeniculate projection fibers in the monkey optic chiasm: a demonstration of the fiber arrangement by means of wheat germ agglutinin conjugated to horseradish peroxidase

The fiber arrangement of the retinogeniculate pathway was investigated in the chiasm of Japanese monkeys (Macaca fuscata) by an iontophoretic injection of wheat germ agglutinin conjugated to horseradish peroxidase into the lateral geniculate nucleus (LGN). It has been claimed that there is a distinct retinotopy in the monkey chiasm, despite lack of any clear anatomical evidence. However, the present data indicate a rather gross retinotopy or almost no discernible retinotopy. Fibers from the foveal-to-peripheral axis of the temporal retina show substantially no retinotopy owing to a marked overlap of fibers in the anterolateral and the posterocentral parts of the ipsilateral hemichiasm. In contrast, the foveal-to-peripheral axis of the nasal retina is re-formed in a gross dorsoventral order in the chiasm. That is, nasal foveal-parafoveal fibers which arise from small cells (which are P beta mode) pass in the dorsal part of the chiasm adjacent to the brain. They widely overlap nasal perifoveal fibers which cross the chiasm more ventrally with very little contact with the brain. The nasal perifoveal fibers also widely overlap nasal peripheral fibers which cross the chiasm more ventrally. Furthermore, the nasal peripheral fibers overlap nasal far peripheral fibers which arise from large cells (including many of the P alpha mode) which run near the pial surface. Fibers from the dorsal and ventral nasal retina cross the midline of the posterior and anterior parts of the chiasm, respectively, and are finally positioned in the medioventral and ventrocentral parts in the tract. Consequently, the dorsoventral retinal axis is re-formed posteroanteriorly in the midline of the chiasm and in a roughly mediolateral direction in the tract. Furthermore, the present study shows that the nasal and temporal retinal fibers coming from the same eye are acutely segregated in the prechiasmal region and the anterior part of the hemichiasm.

Modulation of morphology, proliferation and collagen synthesis in fibroblasts by the exudate from hypersensitive granulomatous inflammation in rats

We examined the effects of the exudate, collected from rats in which hypersensitive granulomatous inflammation was induced by methylated bovine serum albumin, on the function of inflammatory fibroblasts in culture. Addition of the exudate to the fibroblast culture induced changes in fibroblast morphology, identified by staining with antirat prolyl hydroxylase. Phase-contrast microscopy revealed that the exudate-treated fibroblasts became elongated and formed a network. Scanning electron microscopy showed that numerous long pseudopods covered the surface of the fibroblasts. Transmission electron microscopy revealed microfilament bundles with dense zones parallel to the long axis of the cell and nuclei with folds and indentations. Microfilaments were also visible in the elongated pseudopods. These features were consistent with those of myofibroblasts. The exudate also stimulated fibroblast proliferation and collagen synthesis. These findings suggest that the exudate contained certain factors that modulated fibroblast morphology, proliferation, and collagen synthesis. It is possible that putative endogenous factor(s) at the sites of inflammation modulate the development, contraction, and fibrosis of granulation tissue in hypersensitive granulomatous inflammation.

Analysis of transmural trend of myocardial integrated ultrasound backscatter for differentiation of hypertrophic cardiomyopathy and ventricular hypertrophy due to hypertension

OBJECTIVES

This study was undertaken to differentiate hypertrophic cardiomyopathy from hypertensive hypertrophy using a newly developed M-mode format integrated backscatter imaging system capable of calibrating myocardial integrated backscatter with the power of Doppler signals from the blood.

BACKGROUND

Myocardial integrated ultrasound backscatter changes in patients with hypertrophic cardiomyopathy; however, it is unknown whether ultrasound myocardial tissue characterization may be useful in differentiating hypertrophic cardiomyopathy from hypertensive hypertrophy.

METHODS

Calibrated myocardial integrated backscatter and its transmural gradient were measured in the septum and posterior wall in 31 normal subjects, 13 patients with hypertensive hypertrophy and 22 patients with hypertrophic cardiomyopathy. The gradient in integrated backscatter was determined as the ratio of calibrated integrated backscatter in the endocardial half to that in the epicardial half of the myocardium.

RESULTS

Cyclic variation of integrated backscatter was smaller and calibrated myocardial integrated backscatter higher in patients with hypertrophied hearts than in normal subjects, but there were no significant differences in either integrated backscatter measure between patients with hypertensive hypertrophy and those with hypertrophic cardiomyopathy. Transmural gradient in myocardial integrated backscatter was present only in patients with hypertrophic cardiomyopathy (5.0 +/- 1.8 dB [mean +/- SD] for the septum; 1.2 +/- 1.6 dB for the posterior wall).

CONCLUSIONS

Hypertrophic cardiomyopathy and ventricular hypertrophy due to hypertension can be differentiated on the basis of quantitative analysis of the transmural gradient in integrated backscatter.

[Age-related changes in the visual function of WBN/Kob rats--an electrophysiological study]

Changes in the visual function of the male WBN/Kob rat known as diabetic strain with increasing age were studied electrophysiologically. The measurements of electroretinogram (ERG) and visual evoked potential (VEP) in male WBN/Kob rats were performed at 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 weeks of age, and compared with those in male Wistar/ST rats used as control. The prolonged latencies and decreased amplitudes of a- and b- waves and oscillatory potentials of ERG in WBN/Kob rats aged over 17 or 27 weeks were recorded under the light or after 20 min dark adaptation. The visual abnormality as indicated by non-recordable ERG was obvious in WBN/Kob rats aged 67 and 80 weeks. No changes of N1, P and N2 peak latencies of VEP were recorded in WBN/Kob rats with increasing age. The amplitudes between N1 peaks and P peaks decreased remarkably in WBN/Kob rats aged 54 weeks. The amplitudes of VEP in 67 or 80 weeks old rats in which ERG disappeared showed 26 or 28% of those in 5 weeks old rats. From these results, recording of ERG and VEP suggested that the visual abnormality occurred in male WBN/Kob rats aged 67 or 80 weeks and the process of visual abnormality with increasing age was clarified.

Age-related changes in the visual organ of WBN/Kob rats--an ophthalmoscopical study

Changes in the visual organ with aging were investigated non-surgically in male WBN/Kob rats, in which spontaneous diabetic mellitus commonly occurs. Male Wistar/ST rats at the ages of 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 weeks were examined for changes in the peri-orbital region, eyelid, lens, corpus vitreum and ocular fundus by macroscopic inspection and fundoscopy. The area around the eyelid was stained with reddish-brown excretions from the Harderian gland. This stain was frequently observed in rats of both strains aged 54 weeks or over, showing no difference in frequency between WBN/Kob rats and Wistar/ST rats. Lens opacity was observed in male WBN/Kob rats aged 67 weeks or over, and narrowing of the retinal artery and vein in those aged 36 weeks or over. The occurrence of lens opacity was consistent with that of visual dysfunction as determined by a test of the ability to differentiate light from dark using a Y-shaped apparatus (Kiyosawa et al., 1993).

Inhibition by tranilast of collagen accumulation in hypersensitive granulomatous inflammation in vivo and of morphological changes and functions of fibroblasts in vitro

We examined the effects of tranilast, an anti-allergic agent, on hypersensitive inflammation and on morphology and functions of fibroblasts. In vivo, tranilast suppressed the content of collagen in granulation tissue of hypersensitive granulomatous inflammation induced by methylated bovine serum albumin (m-BSA) in rats. In culture, tranilast inhibited the TGF-beta-independent inflammatory exudate-induced stimulation of morphological changes of fibroblasts to myofibroblast-like cells and their proliferation. Collagen gel contraction by myofibroblast-like cells and fibroblasts was also inhibited by tranilast. Flow cytometric analysis revealed that tranilast suspended the cell cycle of fibroblasts at the G0/G1 phase. These results suggest that tranilast modulates the fibrosis and contraction of granulation tissue by inhibiting the growth of myofibroblast-like cells and fibroblasts.

[Age-related changes in the visual function of WBN/Kob rats: a behavioral study]

Changes in visual function with increasing age were studied in male WBN/Kob rats, a new diabetic strain. In order to detect visual abnormalities in WBN/Kob rats, 5 WBN/Kob and 5 Wistar/ST (control) rats from each group were examined at 5, 9, 13, 17, 23, 27, 36, 45, 54, 67 and 80 weeks of age using dark and light distinction and open-field tests. The rates at which WBN/Kob rats selected the dark area were 85.0 to 100%, 58.8% and 52.6% at 5 to 54, 67 and 80 weeks of age, respectively, while those for Wistar/ST rats were 85.0 to 100% in each age group. Visual abnormality was obvious in WBN/Kob rats aged 67 and 80 weeks, compared with Wistar/ST rats (P < 0.05). There were no significant signs of visual abnormality in the open-field test. Detection of visual abnormality seems to be possible from 67 weeks of age.

Skin L-tryptophan-2,3-dioxygenase and rat hair growth

We have identified a new enzyme, skin L-tryptophan-2,3-dioxygenase (skin TDO), that catalyzes the degradation of L-tryptophan into formylkynurenine in rats. The rate of this degradation peaks in all rats at 5 to 6 weeks after birth, and also, among rats depilated at 8 weeks old, at 10 to 11 weeks after birth. We have also observed that the properties of this enzyme are closer to those of hepatic L-tryptophan-2,3-dioxygenase (hepatic TDO) than to indoleamine 2,3-dioxygenase. Although an intraperitoneal injection of L-tryptophan increased the activity of skin TDO to approximately 2.2 times greater than control values, an intraperitoneal injection of hydrocortisone and alpha-methyl-DL-tryptophan, both compounds known to affect hepatic TDO activity, had no effect on skin TDO activity. The molecular weight of skin TDO was estimated to be 16.0 kDa, which is close to the molecular weight of hepatic TDO, yet a much larger molecule than indoleamine-2,3-dioxygenase. Increased hair growth rates paralleled increased levels of skin TDO activity in 5- to 6-week-old rats, and marked increases in the activity of skin TDO occurred 2 or 3 weeks after depilation. Enzyme activity was also greatest 2 days before the time of maximum hair root length. Therefore, skin TDO may play an important role in the initiation or suppression of rat hair growth.

[Visual evoked potential from dura in rats]

Visual evoked potentials (VEPs) were recorded from 8 different points (from points A and B near the bregma to points G and H near the occipital bone) of the dura under parietal bone in rats. The study was performed with 68 adult male Slc: Wistar/ST rats weighing 259.9-298.0g. VEPs recorded from the dura had a large negative component with a peak around 45 msec (N1), a large positive component with a peak around 75 msec and a large negative component with a peak around 120 msec (N2). Points A and B were not suitable for recording of the VEPs because some rats showed no N2 peak. The amplitude of peaks N1 to P at point E, upper the left optic layer of the superior colliculus, was higher than those from other points. Point E was the best position for recording of the VEP from dura in Slc: Wistar/ST rats.

[Possibility of detecting visual functional disturbance in rats by the open-field test]

In order to determine whether visual disturbance in small rodents is detectable by means of the open-field test, the ambulation scores of enucleated and intact rats in an open-field were measured. In a 30-min test of Slc:Wistar/ST rats, there were significant differences in ambulation scores between enucleated and intact rats in the first 10-min. In addition, the effects of observation times (09:00-11:00, 13:00-15:00 and 17:00-19:00 hr) and strains on the open-field test were studied using a 10-min test. Regardless of observation times, ambulation scores of enucleated rats of the Slc:Wistar/ST and F344/N Slc strains were significantly elevated as compared with those of intact rats from both strains. When tested during the 13:00-15:00 hr period, there were significant differences in the Slc:SD rats. These findings indicate that the changes in ambulation are due to visual disturbance. However, significant ambulatory changes in F344/N Slc rats were documented at the three different observation times. Based on these results, Slc:Wistar/ST rats appear to be suitable for detecting visual disturbance by the open-field test.

[Comparison of the gold wire electrode with cotton wick electrode for electroretinography in small laboratory animals]

Using the gold wire and cotton wick electrodes, the electroretinograms of mice and rats were measured, and then they were compared. The results obtained were as follows: 1) There were no remarkable differences in the latencies and amplitudes of a- and b-waves, amplitudes and numbers of waves of oscillatories between two different electrodes. 2) It was easy to make and maintain the gold wire electrode as compared with the cotton wick electrode. From these results, it appears that the gold wire electrode is useful for measuring the electroretinogram of small laboratory animals.

Importance of left ventricular minimal pressure as a determinant of transmitral flow velocity pattern in the presence of left ventricular systolic dysfunction

OBJECTIVES

This study was designed to assess whether the transmitral flow velocity pattern provides an estimation of left atrial pressure irrespective of the presence of left ventricular systolic dysfunction and, if not, to clarify the mechanism.

BACKGROUND

The pulsed Doppler transmitral flow velocity pattern, particularly peak early diastolic filling velocity, has been shown to change in parallel with left atrial pressure. However, extremely elevated left atrial pressure in association with heart failure does not necessarily cause an increase in peak early diastolic filling velocity in patients.

METHODS

Left atrial pressure was elevated with intravenous saline infusion in 11 dogs (normal left ventricular function group) and hemodynamic, transesophageal Doppler echocardiographic and M-mode echocardiographic variables were recorded at three different loading levels. In another 12 dogs, left atrial pressure was elevated by production of left ventricular systolic dysfunction with the stepwise injection of microspheres into the left coronary artery (left ventricular dysfunction group) and the same set of recordings was obtained at three different levels of dysfunction.

RESULTS

Peak early diastolic filling velocity increased with left atrial pressure in the normal left ventricular function group and correlated with mean left atrial pressure (r = 0.61, p < 0.01) and early diastolic left atrial to left ventricular crossover pressure (r = 0.71, p < 0.01). In contrast, peak early diastolic filling velocity did not increase with left atrial pressure in the left ventricular dysfunction group and did not correlate with mean left atrial pressure (r = -0.05) or the crossover pressure (r = 0.06). Peak early diastolic filling velocity correlated well with the difference between the crossover pressure and left ventricular minimal pressure in the left ventricular dysfunction group (r = 0.64, p < 0.01). In contrast to peak early diastolic filling velocity, deceleration time of the early diastolic filling wave correlated with mean left atrial pressure and the crossover pressure irrespective of the primary cause of preload alteration (r = -0.54, r = -0.59, p < 0.01 respectively, n = 69 for all data).

CONCLUSIONS

Preload dependency of the Doppler transmitral flow velocity pattern is hampered if an increase in left atrial pressure is due to left ventricular systolic dysfunction. In this setting, the increase in left ventricular minimal pressure due to left ventricular systolic dysfunction cancels the effect of the increase in left atrial pressure on the flow velocity pattern.

Myocardial hibernation in the infarcted region cannot be assessed from the presence of stress-induced ischemia: usefulness of delayed image of exercise thallium-201 scintigraphy

To examine the relationship between the improvement of wall motion in infarcted regions after percutaneous transluminal coronary angioplasty (PTCA) and thallium-201 uptake in the delayed image of exercise thallium-201 scintigraphy before PTCA, 14 patients with anterior old myocardial infarction were studied. Exercise thallium-201 scintigraphy was performed before PTCA of left anterior descending artery, and mean percent thallium-201 uptake of abnormal segments was calculated in the initial and 4-hour delayed images. Left ventricular angiography was performed during catheterization, before, and 4 to 13 months after PTCA; and regional ejection fraction of anterior wall was calculated. Atrial pacing stress test with the measurement of lactate concentration of aorta and great cardiac vein was performed during catheterization before PTCA. In five patients with mean percent thallium-201 uptake in the delayed image < or = 50% (group I), regional ejection fraction did not increase after PTCA (23% +/- 9% to 24% +/- 12%). In the other nine patients with mean percent thallium-201 uptake > 50% (group II), regional ejection fraction increased significantly after PTCA (39% +/- 18% to 47% +/- 14%; p < 0.05). There was no significant difference in regional ejection fraction, lactate extraction ratio during maximal pacing, and the redistribution of exercise thallium-201 scintigraphy between the two groups before PTCA. Thus the delayed image before PTCA is useful to detect reversible nonfunctioning viable myocardium (hibernating myocardium) in the infarcted region. However, the wall-motion abnormality and the degree of stress-induced ischemia in the infarcted region before PTCA may not be necessarily useful for the detection of hibernating myocardium.

Decreased and abnormal left ventricular filling in acute heart failure: role of pericardial constraint and its mechanism

Pericardial constraining force is minimal in normal hearts; however, it is considered to be prominent in moderate to severe heart failure. Thus, effects of the pericardium on pulsed Doppler transmitral flow velocity pattern were examined in 17 dogs with acute left ventricular dysfunction. Left ventricular dysfunction with left ventricular end-diastolic pressure > or = 15 mm Hg was produced by injection of microspheres into the left coronary artery. Transmitral flow velocity pattern, left atrial and left ventricular diameters, and high-fidelity left atrial and left ventricular pressures were recorded before and after pericardiectomy. In five of the 17 dogs, mitral regurgitation with giant "v" wave of left atrial pressure occurred with reductions of left ventricular systolic pressure and peak rate of the left ventricular pressure fall (dP/dt) after pericardiectomy. In the other 12 dogs, peak early and late diastolic filling velocities increased with a decrease in left ventricular minimal pressure and increases in left arterial and left ventricular diameters and left atrial and left ventricular compliance after pericardiectomy. In these 12 dogs, left atrial to left ventricular crossover pressure, left ventricular end-diastolic pressure, and references for left ventricular relaxation did not change after pericardiectomy. Thus the release from pericardial constraining force in severe heart failure may increase chamber compliance of the left ventricle and left atrium and, in turn, increase peak early and late diastolic filling velocities through an increment in forward transmitral pressure gradient. Increased pericardial constraining force is a possible cause limiting left ventricular filling and hence cardiac output in heart failure.

Comparative studies on inflammatory reactions induced by non-immunological and immunological stimuli in an air pouch and in a carboxymethyl cellulose (CMC)-induced inflammatory pouch

Inflammatory reactions were compared in the air pouch and the CMC pouch. Inflammation was induced by injection of CMC as a non-specific irritant, lipopolysaccharide (LPS) as an activator of macrophages, and methylated bovine serum albumin (m-BSA) as an inducer of delayed type hypersensitivity. There was no prominent difference in the inflammatory reactions following injection of 2% CMC solution into a 4-day-old air pouch and a 3-day-old CMC pouch. On the other hand, injection of 4 ml of 100 ng/ml LPS into each of the pouches enhanced the inflammatory reactions in the CMC pouch several-fold compared with those in the air pouch. A similar tendency was found in the case of an injection of 1 ml of 1 mg/ml m-BSA in rats sensitized with 1 mg of m-BSA. The enhanced inflammatory reactions induced by the injection of LPS or m-BSA were inhibited by dexamethasone, but not by indomethacin. These results indicate that the enhanced inflammatory reactions induced by CMC are related to lining tissue formation, which was a common characteristic in both pouches. Enhanced inflammatory reactions following injection of LPS and m-BSA were related to the activation of macrophages and newly formed blood vessels, which were not characteristic features in the air pouch, but were in the CMC pouch, in addition to the lining tissue. Cyclo-oxygenase products were not associated with the reactions.

[The application of industrial endoscope to observation of the ocular-fundus in small laboratory animals]

Observation and recording methods of the ocular-fundus in small laboratory animals were studied using the industrial endoscope and VTR systems, respectively. The ocular-fundus was observed widely, brightly and clearly in the usual animal facility. In addition, the ocular-fundus was recorded easily and it was possible to examine the ocular-fundus recorded by the VTR systems.

A WGA-HRP study of the fiber arrangement in the cat optic radiation: a demonstration via three-dimensional reconstruction

The fiber arrangement of the optic radiation was investigated in fourteen adult cats. The retinotopies of the lateral geniculate nucleus (LGN) were first identified electrophysiologically, and thereafter, wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) was iontophoretically injected into defined positions of the LGN. These corresponded to the central (medial LGN), horizontal peripheral (lateral LGN), dorsal (rostral LGN), and ventral (caudal LGN) retina. Geniculocortical fibers from the each position of the LGN and corticogeniculate fibers projecting to these positions were always labeled reciprocally. Labeled terminals were found massively in layer IV with some extending to the lower part of layer III, but layers VI and I also contained substantial numbers. Although most of the labeled neurons were localized in layer VI, some neurons were labeled in layer V and transsynaptically in layer IV. Labeled fibers were superimposed in three-dimensionally reconstructed maps of the white matter for the easy understanding of the pathways connecting the LGN and the visual cortex. They were localized in certain zones in the white matter without wide dispersion; however, we did not obtain any findings which suggested clearly different populations of geniculocortical and corticogeniculate fibers. In agreement with previous studies, fibers from the rostral LGN and the caudal LGN projected to the striate cortex in a regular order, rostrocaudally, and fibers from the medial LGN and the lateral LGN projected to the striate cortex inversely (i.e. lateromedially). This inverse projection resulted because fibers from the lateral LGN traversed fibers from the medial LGN in a lateromedial direction; however, there was only partial crossing of these two pathways. The distribution of geniculocortical fibers together with corticogeniculate fibers formed topographic zones arrayed mediolaterally in the white matter. Thus, fibers of the medial LGN were positioned in the intermediate zone, and fibers of the rostral LGN and the lateral LGN were positioned in the rostral and caudal parts of the lateral zone, respectively. Fibers of the caudal LGN were found in the medial zone. This fiber arrangement displayed a rough centroperipheral retinotopy in that fibers representing the central area were placed between fibers representing the peripheral retina. Finally, this fiber arrangement was compared with that of the optic nerve and optic tract.

Relation between height and the maximum conduction velocity of the ulnar motor nerve in human subjects

The maximum motor nerve conduction velocity of the right and left ulnar motor nerve was measured in more than 650 healthy medical students of both sexes. There was no side difference in the maximum conduction velocity. The shorter person has a statistically significant higher conduction velocity than the taller person. Comparison of students of both sexes showed a slightly higher conduction velocity in females. However, with regard to its relation to height, the conduction velocity was higher in males.

Enhancement of inflammatory reactions in a non-immunological air pouch model in rats

In a carboxymethyl cellulose (CMC) air pouch inflammation model, accumulation of exudate decreased at a relatively rapid rate and almost disappeared 3 days after a 2% CMC injection into the preformed air pouch. After a second injection of 2% CMC solution into the 1-day-old CMC pouch on the day following the first CMC injection, the decrease in rate of exudate was similar to the change seen after the first CMC injection. In another group of rats, 3 days after the first CMC injection when inflammation had subsided, a second injection of 2% CMC solution into the 3-day-old CMC pouch resulted in a marked increase of exudate accumulation, inflammatory cell infiltration and vascular permeability. Histologically, large numbers of macrophages accumulated in the 3-day-old CMC pouch and fibroblast proliferation and newly formed blood vessels were also visible. The enhanced exudative reaction was significantly inhibited by dexamethasone but not by indomethacin. These results indicate that the enhanced inflammatory reactions appear to be closely correlated with the increase of reactivity at the site of inflammation and the exudative reaction was not mediated by cyclo-oxygenase products.

Micronucleus test with 6-mercaptopurine monohydrate administered intraperitoneally and orally

The effect of route of administration on the induction of micronucleated polychromatic erythrocytes (MNPCEs) was examined. 6-Mercaptopurine monohydrate (6-MP) was administered intraperitoneally (i.p.) or orally (p.o.) to 2 strains of mice, MS/Ae and CD-1. From the results of an acute toxicity test and a pilot micronucleus test, the doses selected for the final micronucleus test were 12.5-100 mg/kg for the i.p. route and 25-200 mg/kg for the p.o. route. The sampling time was 48 h. Frequencies of MNPCEs increased dose-dependently by the i.p. route but peaked at 50 or 100 mg/kg for the p.o. route. 6-MP induced MNPCEs more efficiently after p.o. administration than after i.p. treatment in both strains.

Retinogeniculate projection fibers in the monkey optic nerve: a demonstration of the fiber pathways by retrograde axonal transport of WGA-HRP

Seven Japanese monkeys (Macaca fuscata) were used to investigate the fiber pathways of the optic nerve. Optic nerve fibers and retinal ganglion cells were retrogradely labeled by iontophoretic injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) into electrophysiologically defined positions of the lateral geniculate nucleus (LGN). By gross anatomical observation, the optic nerve usually had one distinct bend, which flexed dorsally 3-4 mm from the eyeball, and occasionally another ventrally directed bend was found just behind the eyeball. In the optic nerve head, fibers from the various retinal areas were arranged in a wedge according to the fiber trajectory on the retinal surface. For about a 3 mm distance from the disc, fibers rapidly spread out radially. Subsequently, rather than scattering dorsoventrally, they progressed to the chiasm with a gradual increase in the degree of mediolateral (nasotemporal) scatter. The degree of the scatter was different depending on the retinal site from which the axons originated. Fibers from the peripheral retina spread out widely for a few millimeters behind the eyeball. Thereafter the scatter was rather limited until the chiasm. On the other hand, the scatter of fibers from the foveal and parafoveal areas progressed gradually through the nerve. The present study also suggests that the difference in scatter depends on the types of cells of origin. Fibers from large ganglion cells displayed more extensive scatter than fibers from medium-sized cells. In spite of the extensive scatter of fibers, two clear segregations were found; one was a dorsoventral segregation, which was displayed by both central and peripheral retinal fibers, and the other was a center-peripheral segregation in which the fibers from the nasal central (papillomacular) retina were located almost exclusively in the central part of the optic nerve surrounded by peripheral retinal fibers. However, the temporal central retinal fibers were located in the lateral periphery of the nerve, and they overlapped significantly with fibers from the temporal peripheral retina. Furthermore, a broad intermingling was found between nasal and temporal peripheral retinal fibers owing to their mediolateral scatter. Thus, the present findings based on more precise anatomical techniques indicate that the classical notion of the retinal quadrant topography in the monkey optic nerve probably is suspect. In addition, the "rotation" of the fiber arrangement was not demonstrated.

Tryptophan 2,3-dioxygenase activity in rat skin

We have found an enzyme system that catalyzes the conversion of L-tryptophan to L-kynurenine, presumably via L-formylkynurenine, in soluble and insoluble fractions of rat skin. The enzymatic activity was stimulated by hematin, ascorbate, and catalase, but not by methylene blue. Highest activity was located in the skin of the dorsal posterior region and lowest activity in the abdominal region. The activity in plucked (depilated) skin was only about 25% of that obtained from unplucked (depilated) tissue of the same region. D-Tryptophan, 5-hydroxytryptophan, and tryptamine were not degraded by the skin enzyme and the Km for L-tryptophan determined with the crude enzyme was 1 microM. The decycling activity of rat skin and liver for L-tryptophan began to be stimulated after birth and reached the highest level at 6 weeks. But, 1 week later, most of the skin activity suddenly disappeared and the low level continued at least until 12 weeks. In contrast, the hepatic enzyme did not change so drastically. These findings suggest that an enzyme that catalyzes L-tryptophan to L-kynurenine via L-formylkynurenine is present in rat skin.

Species differences in the effects of bezafibrate, a hypolipidemic agent, on hepatic peroxisome-associated enzymes

The effects of bezafibrate on hepatic peroxisome-associated enzymes of rats, mice, guinea pigs, hamsters, rabbits, dogs and monkeys were examined. Dogs and monkeys were given bezafibrate orally at 30 mg/kg body wt daily for 2 weeks and at 125 mg/kg body wt daily for 13 weeks, respectively, and other species at 100 mg/kg daily for 2 weeks. In male rats, marked changes were observed in the activities of catalase (1.73-fold), D-amino acid oxidase (DAAO; 0.56-fold), fatty acyl-CoA oxidizing system (FAOS; 12.9-fold) and carnitine acetyltransferase (CAT; 35.8-fold); in female rats, the changes were less than in the males. In mice, there were no apparent sex differences in the responses of hepatic peroxisomal enzymes to bezafibrate and the increases in the activities of catalase, FAOS and CAT were 1.76-, 3.75- and 7.94-fold respectively. In guinea pigs, only slight increases in the activities of FAOS (3.00-fold) and CAT (2.83-fold) were observed. In hamsters, the increases in catalase, FAOS and CAT activities, were 1.23-, 2.19- and 2.77-fold respectively. Although rabbits and dogs showed slight increases in CAT activity, no significant response to the drug was observed in monkeys. Hepatomegaly and the increase of hepatic content of peroxisome proliferation-associated polypeptide (PPA-80), which has been recognized as a peroxisomal bifunctional protein in the fatty acid beta-oxidation pathway, were observed only in rats and mice. These results show that there were marked species differences in the effects of bezafibrate on hepatic peroxisomes, and that bezafibrate induced hepatic peroxisome proliferation in rodents, especially rats and mice.

An electron microscopic study of early pathology in chondromalacia of the patella

For a study of the ultrastructural pathology of chondromalacia patellae, we studied biopsy specimens that had been obtained at operation in twelve young patients who had pain in the anterior aspect of the knee due to mechanical derangement and also had the pathological changes in articular cartilage that are characteristic of chondromalacia. The initial pathological finding was swelling of the superficial matrix associated with breakdown of the collagen fiber network, especially at matrix streaks in the superficial and transitional zones. Fibrillated cartilage contained surface fissures that penetrated the middle layers. Amorphous electron-dense material was found covering the internal surfaces of the fissures; this appeared to contain degraded components of the matrix. In association with these changes, there were formation of nests of cells (clusters of chondrocytes) and increased numbers of organelles in the chondrocytes. A limited repair reaction also was observed in some specimens; this was characterized by the migration of fibroblast-like cells over the surface of the cartilage. The ultrastructural observations on these specimens from patients who had chondromalacia were compatible with a pathogenesis resulting from mechanical overload.

Determination of kynurenine in serum by high-performance liquid chromatography after enzymatic conversion to 3-hydroxykynurenine

A method for the determination of the physiological level of kynurenine in human serum based upon conversion of kynurenine to 3-hydroxykynurenine by enzymatic reaction with the mitochondrial fraction and NADPH and analysis by reversed-phase high-performance liquid chromatography with electrochemical detection is described. Tryptophan gave no interference. For one analysis, 0.2 ml of serum was sufficient, compared with the large volume (5.0 ml) required for other methods.

Selective inhibition of collagen accumulation by N-(3,4-dimethoxycinnamoyl)anthranilic acid (N-5') in granulation tissue

The effect of topically applied N-5', an inhibitor of chemical mediator release from mast cells, on the carrageenin-air-pouch inflammation was studied. The formation of granulation tissue, the accumulation of exudate and the number of infiltrating cells were significantly reduced by the treatment with N-5' (100 mg/kg). The collagen content in granulation tissue was dose-dependently reduced without affecting the noncollagen protein and DNA content by treatment with N-5'. At a dose of 100 mg/kg of N-5', prolyl hydroxylase activity in the tissue was significantly decreased. The selective inhibition of collagen accumulation in granulation tissue resulted from reduction of collagen biosynthesis in vivo. N-5' did not directly inhibit collagen synthesis by diploid fibroblasts, but inhibited fibroblast proliferation in culture. Such results indicate that one of the inhibitory mechanisms of collagen accumulation by N-5' in inflamed sites may involve the inhibition of fibroblast proliferation.

Course of retinogeniculate projection fibers in the cat optic nerve

The fiber courses of the cat optic nerve were studied by using wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP), which was iontophoretically applied to electrophysiologically defined positions in the lateral geniculate nucleus (LGN). Grossly, there were two distinct bends along the length of the optic nerve. The ventrally flexing anterior bend was located approximately 2 mm from the eyeball, while the dorsally flexing posterior bend was found at some 6 mm distant. The optic nerve fibers showed a tendency to scatter toward the chiasm. At the optic nerve head, the fibers from the different retinal areas maintained the retinal topography in a simplified form according to the trajectory of optic fibers surrounding the optic disc. Between the anterior and posterior bends, the fibers from the pericentral, middle-temporal, and most upper areas of the dorsal retina migrated ventrally and were arranged in the middle of the lateral, middle, and medial parts of the optic nerve, respectively, while fibers from the middle-temporal area of the ventral retina migrated dorsally and scattered into the lateral half. The fibers from the temporal and nasal horizontal meridian areas tended to hold their respective positions in the lateral and medial halves of the optic nerve. As a result, in this level they displayed a complex retinotopy in that the fibers from each part of the retina were mixed. Passing the posterior bend, as the optic nerve proceeded toward the chiasm, the characteristic pattern became less defined. Near the chiasm, the retinotopy became very scattered, showing a partial dorsoventral inversion of the retinal topography with substantial overlapping. It was noted from the present findings that the fibers from ventral retina scattered more quickly than the fibers from the dorsal retina, which tended to hold their grouping until the anterior bend, but the central or pericentral retinal fibers proceeded without significant scatter as far as the posterior bend. The analysis of labelled ganglion cells suggested that even if fibers that arise from one certain "mode" of ganglion cells are selected, it is unlikely that they maintain their initial fiber topography along the entire length of the optic nerve.

Role of cytosolic superoxide dismutase as a stimulator in anthranilamide hydroxylation by a microsomal monooxygenase system in rat liver

We have isolated a protein factor from rat liver which stimulates anthranilamide hydroxylation by the microsomes in the presence of NADPH and oxygen and showed this factor to contain Cu and Zn and to have superoxide dismutase activity [Biochim. Biophys. Acta 365, 148-157 (1974)]. In the present study, this protein factor was confirmed to be a superoxide dismutase (SOD) by comparison of the recovery of SOD activity with that of anthranilamide hydroxylation-stimulating activity at each step of its purification, by inhibition of SOD activity with NaCN and hydrogen peroxide (H2O2), and by recovery of the SOD activity of the protein factor after reconstitution with Cu2+ and/or Zn2+. At a given SOD activity level, there was no difference among the rat liver SOD, Cu,Zn-SOD from bovine erythrocytes, and Mn-SOD from Serratia marcescens in their ability to stimulate anthranilamide hydroxylation not only by rat liver microsomes, but also by the reconstituted cytochrome P-450-containing monooxygenase system. Rat liver SOD stimulated anthranilamide hydroxylation by the reconstituted system in proportion to its amount below a protein concentration of 1 microgram/ml. In anthranilamide hydroxylation by the reconstituted system without SOD, only a slight hydroxylase activity was found at the initial stage of the reaction and a marked increase in the amounts of NADPH oxidized and H2O2 formed was observed after a lag time. In the presence of rat liver SOD, however, the hydroxylase activity was markedly and continuously increased almost proportionally to reaction time with a concomitant decrease in the amounts of NADPH oxidized and H2O2 formed. In addition, a trace of 3-OH anthranilamide, one of the products, not only stimulated NADPH-dependent H2O2 formation in the reconstituted system, but also inhibited the apparent reduction of cytochrome P-450 by NADPH in the reconstituted system. These effects of 3-OH anthranilamide were diminished by rat liver SOD. When a trace of 3-OH anthranilamide were added to a system composed of NADPH-cytochrome c (P-450) reductase and NADPH, H2O2 formation and NADPH oxidation were markedly stimulated. However, on addition of 3-OH anthranilamide to the system containing rat liver SOD, no stimulation on either H2O2 formation or NADPH oxidation was found.(ABSTRACT TRUNCATED AT 400 WORDS)