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Y Kanno

Publications and source records attributed to Y Kanno.

At least 181 records · Page 10Linked to original sources
PubMed1978

The cell-to-cell channel.

Cells of most organized tissues are interconnected at their junctions by aqueous membrane channels, shown in one instance to be at least 14--16 A in diameter. During junction formation, nascent channels are detected as quantal steps in cell-to-cell conductance, growing progressively in number. The channels detected are stable. Elevation of cytoplasmic free Ca2+ concentration can cause graded closure of channels.

Animals↗
PubMed1977

Energy requirement for the maintenance of membrane potential in rat liver cells in situ.

The transmembrane potential of female rat liver cells in situ was-52.4 mV. This was decreased to -42.9 mV by ethacrynic acid (4 mg/100 g), but not by ouabain (1 mg). DL-Ethionine (25-100 mg) caused a decrease in the membrane potential and tissue ATP content. A high dose ethionine (100 mg) increased tissue Na content and decreased K content. By applying adenine (25 mg) to the animals treated with ethionine (100 mg), the membrane potential, ATP content and K content were increased and the Na content was decreased. The repolarized membrane potential in the animals treated with adenine following the ethionine was again depolarized by the administration of ouabain, but not by the administration of ethacrynic acid. These results suggest that two kinds of active ion transport mechanisms, ethacrynic acid-sensitive and ouabain-sensitive mechanisms, may be involved in maintenance of the membrane potential of rat liver cells.

Adenine↗
PubMed1977

Possible functioning of active ion transport mechanism in the mucous epithelial cells of newt stomach at low temperature.

The membrane potential of mucous epithelial cells of isolated newt stomach was -23 mV on the average at 7 degrees C. The potential decreased when the temperature was lowered further, the normal external solution was replaced with K+-free solution, or ouabain or DNP was applied. The decreased membrane potential level of the cells in K+-free solution was not changed any more by adding ouabain to the solution. The membrane potential increased transiently beyond the control level when the stomach was returned to the normal solution after being exposed to isotonic NaCl solution with EGTA. The transient potential increase was blocked by ouabain. These results suggest that, even at such a low temperature as 7 degrees C, the active ion transport mechanism(s) of mucous epithelial cells in the newt stomach is still capable of functioning to some extent.

Animals↗
PubMed1976

Inhibitory effect of large doses of propylthiouracil and methimazole on an increase of thyroid radioiodine release in response to thyrotropin.

Thyroidal radioiodine release increased shortly after a single injection of small doses of PTU, while moderate doses of MMI produced a similar increase of thyroidal radioiodine release with a latency of 7-9 hr. Large doses of PTU and MMI failed to augment thyroidal radioiodine release for at least 29 to 34 hr after the initial administration of goitrogens, although plasma TSH increased significantly because of goitrogen administration. An increase of thyroid hormone release in response to exogenous TSH was depressed by PTU and MMI in rats and mice treated with T4. Since this depression of TSH action only continued for a short period in spite of continuous administration of goitrogens, and since final thyroidal radioiodine release rate was similar to that produced by small doses of PTU, the effects mentioned were not simply due to general toxic action of goitrogens. It is suggested that large doses of PTU and MMI not only block thyroid hormone synthesis but also interfere with the action of TSH on thyroid hormone secretion.

Animals↗
PubMed1976

[Gross and light microscopic observations of the pudendal nerve of the guinea pig (author's transl)].

Using thirty six adult guinea pigs, the course and distribution of the pudendal nerve was observed macroscopically and then the constitution of the myelinated nerve fibers in these branches was studied with the fan-wise split preparation method (Fukuyama) and the cross sections embeded in paraffin wax. The main findings are summarized as follows: 1) The pudendal plexus in the guinea pig is formed most frequently by a bigeminal nerve which arises from the ventral ramus of the second sacral nerve at an average rate of 55.0% and the pudendal nerve is so independent from the sciatic nerve that the most part of the bigeminal nerve runs into the pudendal nerve. 2) The perineal nerve of the guinea pig arises most frequently with four roots (43.3%). The myelinated fiber constitution of this nerve is as follows: The small-sized fibers occupy 49.8%, the medium--sized 21.9%, the large--sized 15.1%, the maximum--sized 13.1% on an average, and the nerve fiber diameters observed in the cross section shows a bimodality in their distribution, of which the fibers in the higher peak are 1 mu to 2 mu and in the lower peak 5 mu to 8 mu. 3) The dorsal nerve of the penis or clitoris of the guinea pig arises most frequently with one root from the originating roots of the perineal nerve. The relationship between the sciatic and dorsal nerve appears to be scanty. The myelinated fibers of this nerve comprise 50.8% of small--sized, 28.4% of medium--sized, 14.7% of large--sized and 6.2% of maximum--sized fibers on an average. The fiber sized histograms constructed in the cross section shows a unimodality laying at 1 mu to 3 mu and the dorsal nerve of the clitoris contains more medium fibers 3 mu to 6 mu than the perineal nerve. From these results, it seems clear that the genital corpuscles are supplied by these medium fibers. 4) The inferior rectal nerve of the guinea pig arises from the perineal nerve in all cases, however, it is very slender. 5) The branch to the Obturator internus arises from the originating root or main trunck of the perineal nerve (51.7%). The myelinated fiber constitution of this branch is as follows: The maximum--sized fibers occupy 67.6%, the large--sized 16.2%, the small--sized 9.5% and the medium sized 6.8%. On the other hand, the fiber diameters observed in the transverse section are distributed around three peaks lying at 1 mu, 8 mu to 9 mu and 12 mu to 13 mu. 6) The branch to the accessory head of the Semitendinosus arises from the pudendal nerve at an average rate of 91.7%, of which this branch arises most frequently with one root from the originating root of the perineal nerve. The myelinated fiber constitution is as follows: The maximum--sized fibers 50.0%, the large--sized 23.9%, the small--sized 15.9% and the medium--sized 10.2% on an average. The histogram shows that myelinated fibers in this muscular branch consist of two groups of 1 mu to 2 mu and 12 mu to 14 mu...

Animals↗
PubMed1976

Comparative morphological remarks on the origin of the posterior femoral cutaneous nerve.

The origin and course of the posterior femoral cutaneous nerve were observed macroscopically in 38 Japanese adult cadavers which were dissected in the University of Hokkaido, Faculty of Medicine during the years 1971/72 and the results obtained were compared with those from some other mammals (rat, rabbit, dog and cat) and a number of bibliographical findings on the other animals. On the basis of the archetype of the pudendal plexus, the site of origin of the posterior femoral cutaneous nerve was divided into seven portions as follows: the sciatic nerve or inferior gluteal nerve (I) and its originating roots (RI), the bigeminal nerve (B) and its originating roots (RB), the part of junction of I and B (CIB), the pudendal nerve (P) and its originating roots (RP). According to the arising mode, the posterior femoral cutaneous nerve was calssified into seven types: Type A (the sciatic nerve type); the nerve arises from I and RI (horse, rat, bird, frog and salamander). Type B (the sciatic transitional type); the nerve arises from I, RI, CIB, RB and B (MAN AND MONKEY). Type C (the bigeminal nerve type); the nerve arises from CIB, RB and B (gorilla, chimpanzee, orangutan, cat and sphenodon). Type D (the pudendal transitional type); the nerve arises from CIB, RB, B, RP and P (dog). Type E (the pudendal nerve type); the nerve arises from RP and P (pig, cattle and rabbit). Type F (the mixed type); a mixture of A to E types. These various patterns in the posterior femoral cutaneous nerve may be explained by the comparative anatomical explanation on the limb medial rotation given in Braus' text-book of Anatomy (Bd. I, S. 273). From these descriptions it is reasonable to presume that the main trunk of the posterior femoral cutaneous nerve of the tetrapod below the Aves arises from the sciatic nerve and is analogous to the gluteal branches of mammals, with its main stem still retained in the pudendal nerve. If the cutaneous area supplied by the posterior femoral cutaneous nerve expands to the lateral border of the buttock in company with the lower limb medial rotation, the part between this area and that supplied by the pudendal nerve is enlarged. At first, these expanded areas are probably supplied by the branches of the pudendal nerve, which gradually become independent to become the main stem of the posterior femoral cutaneous nerve in mammals. This nerve seems, therefore, to be primarily a division of the pedendal nerve, and so in man has various types of arising patterns, A to E, in accordance with the scheme in the phylogeny. Those hypothetical changes are observed in the human sacral plexus, from which the cutaneous nerve arises with a fan-shaped overlapping.

Animals↗
PubMed1976

[A case of the A. Vertebralis sinistra direct arising from the arcus aorta (author's transl)].

A case of the left vertebral artery direct arising from the Arcus aorta, falling under C-type in ADACHI (1928), was encountered among the corpses dissected for practice in Hokkaido University, school of medicine. The Arcus aorta has four branches; Truncus brachiocephalicus, A. carotis communis sinistra, A. vertebralis sinistra, and A. subclavia sinistra. The A.vertebralis sinistra has passed through at first into Foramen transvwrsarium of the vertebra cervicales quintus (C5). The length of this artery between the origin of the Arcus aorta and the fifth cervicales was 120 mm. The other measurements of arteries were shown in table 1.

Aged↗
PubMed1975

Effect of butyldiiodohydroxybenzoate on pituitary-thyroid interplay.

The effect of BHDB, an analogue of thyroxine, on the pituitary-thyroid system was studied in the rat. BHDB produced low plasma T4 and T3 concentrations similar to those produced by methimazole, but failed to elevate plasma TSH and to produce goiter because of displacement of T4 from the binding protein. Low plasma thyroid hormone concentrations were due to an increase of fecal loss of thyroid hormones. By releasing excess iodide, BHDB blocked the development of goiter produced by methimazole.

Animals↗