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Volume 173 (1994)
- Issue 4 Pages 361-
- Issue 3 Pages 283-
- Issue 2 Pages 199-
- Issue 1 Pages 1-
Volume 173, Issue 3
Displaying 1-8 of 8 articles from this issue
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YASUHIRO TERANISHI, JURO IRIUCHIJIMA1994 Volume 173 Issue 3 Pages 283-289
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSTERANISHI, Y. and IRIUCHIJIMA, J. Hindquarter Vascular Resistance as Compensator for Hypotension in Conscious Rats. Tohoku J. Exp. Med., 1994, 173 (3), 283-289-The purpose of this study was to test whether hindquarter (terminal aortic) vascular resistance uniquely increases in order to compensate for interventions which result in a lowering of arterial pressure. Changes in hindquarter resistance were compared to changes in superior mesenteric resistance after the administration of the nitrovasodilator drug, molsidomine. Hindquarter blood flow or superior mesenteric flow was measured in conscious rats using an electromagnetic flow probe implanted around the terminal aorta or the superior mesenteric artery, respectively. Twenty minutes after an intravenous bolus injection of molsidomine (1mg/kg), ganglionic blockade with hexamethonium bromide (25 mg/kg, i.v.) significantly decreased hindquarter resistance, but not superior mesenteric resistance. In the absence of molsidomine, ganglionic blockade has no effect on resistance in either vascular bed. These findings suggest that excitation of sympathetic vasoconstrictor fibers supplying the hindquarters but not those supplying the superior mesenteric area occurred in response to the hypotensive effect of molsidomine. This is consistent with the hypothesis that augmenting-hindquarter resistance is the first line of defense against hypotensive interventions.View full abstractDownload PDF (674K) -
CHIYOHIKO SHINDOH, WATARU HIDA, HAJIME KUROSAWA, SATORU EBIHARA, YOSHI ...1994 Volume 173 Issue 3 Pages 291-302
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSSHINDOH, C., HIDA, W., KUROSAWA, H., EBIHARA, S., KIKUCHI, Y., TAKISHIMA, T. and SHIRATO, K. Effects of Unilateral Phrenic Nerve Denervation on Diaphragm Contractility in Rat. Tohoku J. Exp. Med., 1994, 173 (3), 291-302- We examined the early effects of phrenic nerve denervation on the diaphragm muscle 1, 3, 7 and 14 days after unilateral denervation in rats. In the denervated hemidiaphragms, force frequency curves at 3, 7 and 14 days decreased significantly by 51%, 50% and 38% respectively of the peak tension of the force frequency curves of the diaphragms of rats with sham operation. Twitch tensions increased significantly at 14 days, and contraction times and half relaxation times slowed significantly at 3, 7 and 14 days. The tensions of denervated diaphragms at 5min during the fatigue runs was significantly increased at 14 days. As determined by histological staining, the mean cross sectional area of fast-twitch fibers (type II) decreased significantly from 2, 742 (sham) to 1, 599μm2 (14 days), but that of the slow-twitch fibers (type I) did not change significantly during the same period. These findings suggest that, during the first two weeks of denervation, fast twitch fibers (type II) atrophy more rapidly than slow twitch fatigue resistant fibers (type I), as confirmed by the contractile properties and histological findings.View full abstractDownload PDF (1639K) -
TEN-JEN LIAO, HIROYASU NISHIKAWA1994 Volume 173 Issue 3 Pages 303-309
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSLiao, T.-J. and Nishikawa, H. The Variation of Action Potential and Impedance in Human Skeletal Muscle during Voluntary Contraction. Tohoku J. Exp. Med., 1994, 173 (3), 303-309-We used an insulated acupuncture needle to deliver a 20kHz alternative current to detect the changes on the electromyogram (EMG) and deep muscle impedance. We found that impedance increased (with a duration of 224.1±75.3msec) and then decreased (with a duration of 293.4±97.3 msec) after motor unit action potential (MUAP) firing during isometric voluntary contraction (VC) of the tibialis anterior muscle (TAM). We divided the positive peak into pattern I (with a latency range of ≥30cosec and ≤75msec) and pattern II (with a latency range of >75msec and ≤140msec). These patterns of change corresponded to the contraction times of tension caused by the electrical stimulation and VC. These impedance changes may be caused by a change in the extracellular and intracellular fractions, and may reflect the variance of tension intensity in the muscle tissue.View full abstractDownload PDF (690K) -
KEIICHI YAMATANI, SEIJIRO MARUBASHI, KAZUYOSHI WAKASUGI, KIMIHITO SAIT ...1994 Volume 173 Issue 3 Pages 311-320
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSYAMATANI, K., MARUBASHI, S., WAKASUGI, K., SAITO, K., SATO, N., TAKAHASHI, K. & SASAKI, H. Catecholamine-Induced cAMP Response in Streptozotocin-Induced Diabetic Rat Liver. Tohoku J. Exp. Med., 1994, 173 (3), 311-320-The effect of prolonged diabetic state on catecholamine-induced adenosine 3', 5'-monophosphate (CAMP) response in the rat liver was examined using isolated liver perfusion. Epinephrine- or isoproterenol-induced cAMP production was enhanced (10-fold of the control) in the liver from extremely emaciated (intraperitoneal adipose tissue was absent completely) diabetic rats 4 weeks after streptozotocin-injection kept without insulin, but not from adipose tissue-present diabetic rats. Glucagon-induced cAMP production was decreased in the diabetic rat liver 4 weeks after streptozotocin regardless of the presence or absence of adipose tissue. Secretin-induced CAMP production was also decreased in the adipose tissue-absent diabetic rat liver. Plasma levels of glucose or insulin were not different between adipose tissue-present and -absent diabetic rats. Liver dysfunction (elevated AST and ALT levels) was observed 1 week after streptozotocin-injection, and worsened at 4 weeks. Forskolin-induced production of cAMP, and oxymetazoline (an α2-adrenergic agonist)-induced suppression of it were not different among the control, newly diabetic (1 week after streptozotocin-injection), and the adipose tissue-absent diabetic rat liver. In conclusion: 1) enhanced β-adrenergic, and decreased glucagon- or secretin-induced CAMP production seems to be caused by different mechanisms; 2) the prolonged severe diabetic state losing adipose tissue may cause a considerable change in metabolism and the characteristics of hepatocyte, and lead to enhanced β-adrenergic cAMP production.View full abstractDownload PDF (1025K) -
MASARU SASAKI1994 Volume 173 Issue 3 Pages 321-336
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSSASAKI, M. Histomorphometric Analysis of Age-Related Changes in Epithelial Thickness and Langerhans Cell Density of the Human Tongue. Tohoku J. Exp. Med., 1994, 173 (3), 321-336-Human tongues were taken from 529 cadavers (age, 0-105 years; 298 males and 231 females). Age-related changes in epithelial thickness and Langerhans cell (LC) density were histomorphometrically analyzed. The epithelial section area (ESA) per 10-mm epithelial surface length (ESL) was measured in the dorsum linguae. After measurement with a computed image processing system at a magnification of ×20, the mean epithelial thickness was calculated. LCs were identified by an immunohistochemical stain with anti-S-100 protein polyclonal antibody and Fontana-Masson's stain. The number of LCs was counted in the measured ESA at a magnification of ×400. LC density per mm ESL and per mm2 ESA was calculated. The lingual epithelium in the older age groups was significantly thinner than that in the younger age groups. The LC density per mm ESL and per mm2 ESA in the older age groups was significantly lower than that in the younger age groups. These results suggest that both physical and immunological defenses of the lingual mucosa might be compromised in old ag.View full abstractDownload PDF (3232K) -
SHOICHI KOKUBUN, OSAMU KASHIMOTO, YASUHISA TANAKA1994 Volume 173 Issue 3 Pages 337-344
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSKOKUBUN, S., KASHIMOTO, O. and TANAKA, Y. Histological Verification of Bone Bonding and Ingrowth into Porous Hydroxyapatite Spinous Process Spacer for Cervical Laminoplasty. Tohoku J. Exp. Med., 1994, 173 (3), 337-344- Three spinous processes of the cervical spine and implanted porous hydroxyapatite spacers were removed from a patient with a recurring intramedullary tumor at revisional laminectomy one year after spinous process splitting laminoplasty. Histological examination of undecalcified sections revealed direct bone bonding to the spacer at three of the six bone-hydroxyapatite interfaces. Bone ingrowth was observed up to 400μm into the implant pores. Fibrous tissue was observed to intervene between the other three bone-hydroxyapatite interfaces. The suspected bone bonding with the spacer on CT scans before the revision was confirmed by the histological findings.View full abstractDownload PDF (5920K) -
JUNICHIRO HASHIMOTO, YUTAKA IMAI, NAOYOSHI MINAMI, MASANORI MUNAKATA, ...1994 Volume 173 Issue 3 Pages 345-354
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSHASHIMOTO, J., IMAI, Y., MINAMI, N., MUNAKATA, M., SAKUMA, H., SASAKI, S., YOSHINAGA, K. and ABE, K. A High-Salt Diet Alters Circadian Blood Pressure Rhythm in Dahl Rats. Tohoku J. Exp. Med., 1994, 173 (3), 345-354-To determine whether salt loading and salt sensitivity are related to the circadian variation in blood pressure (BP), we studied the circadian rhythm of BP in Dahl rats. Thirteen Dahl salt-sensitive (Dahl-S) and 14 salt-resistant (Dahl-R) rats were fed a high- or low-salt diet after weaning. Mean arterial pressure (MAP) and heart rate (HR) were measured every 4sec throughout 24hr in freely moving rats, and the data obtained were analyzed quantitatively by the cosinor method. MAP mesor was significantly elevated in Dahl-S rats on a high-salt diet (SH), as compared with those on a low-salt diet (SL), but there was no difference in the MAP mesor between Dahl-R rats on a high-salt diet (RH) and those on a low-salt diet (RL). MAP amplitude was significantly greater and HR amplitude was smaller in SH rats than in SL rats; the amplitudes of MAP and HR in RH rats were similar to those in RL rats. MAP acrophase was significantly delayed in SH and RH rats as compared with SL and RL rats, respectively; the time delay in the MAP acrophase was not accompanied by a synchronized delay in HR acrophase. The time delay in MAP acrophase was greater in SH rats than in RH rats. These results indicate that salt loading influences the amplitude and acrophase of BP, and that the effect of salt loading on circadian BP rhythm is modulated by salt sensitivity.View full abstractDownload PDF (996K) -
KAZUNARI SATO, KUNIHIKO TERADA, TOSHIHIRO SUGIYAMA, SATSUKI TAKAHASHI, ...1994 Volume 173 Issue 3 Pages 355-360
Published: 1994
Released on J-STAGE: August 31, 2006
JOURNAL FREE ACCESSSATO, K., TERADA, K., SUGIYAMA, T., TAKAHASHI, S., SAITO, M., MORIYAMA, M., KAKINUMA, H., SUZUKI, Y., KATO, M. and KATO, T. Frequent 4verexpression of Vascular Endothelial Growth Factor Gene in Human Renal Cell Carcinoma. Tohoku J. Exp. Med., 1994, 173 (3), 355-360-Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an inducer of an-giogenesis. Expression of the VEGF gene was investigated in 20 patients with renal cell carcinoma by Northern blot hybridization analysis. Of the 20 tumors, 2 (60%) overexpressed the gene 3.0 times more than in normal renal tissues. No significant correlation was found between overexpression of the VEGF gene and the histopathological data such as grade, cellular and structural subtypes, stage and size of tumor. These results suggest that VEGF is produced by the tumor cells and is responsible for development of this hypervascular tumor.View full abstractDownload PDF (703K)
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