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Y Iwabuchi

Publications and source records attributed to Y Iwabuchi.

43 records · Page 3Linked to original sources
PubMed1988

A comparative study of the effects of four choline esters on the secretion of fluid and glycoprotein from rat submandibular glands.

The actions of four choline esters, acetylcholine (ACH), methacholine (MET), carbachol (CAR) and bethanechol (BET), on the secretion of saliva and the specific glycoprotein (GP) contained in the secretory cells of the submandibular gland (SMG) of the rat were compared under conditions with and without physostigmine (PHY). The ED50 values with respect to salivation were 17 mg/kg for ACH, 1060 micrograms/kg for BET, 810 micrograms/kg for MET and 75 micrograms/kg for CAR, whereas after pretreatment with PHY, ED50 values were lowered to 7.5 mg/kg for ACH and 212 micrograms/kg for MET, but remained unchanged for CAR and BET. SDS-polyacrylamide gel electrophoresis demonstrated that the saliva from the SMG elicited by the four choline esters contained GP I (130 KDa) and GP IV (21.5 KDa), characteristic of the acinus, and a band of GP III (31 KDa), which originates from the granular tubules. The order of intensity of these bands was band I much greater than band III = band IV. Among these bands, band I increased in intensity in a dose-dependent manner. These results suggest that the four choline esters act mainly on the acinar cells, but exert some effects on the granular tubules of the rat SMG.

Acetylcholine↗
PubMed1988

Face EMG Topographic analysis of mimetic movements in patients with Bell's palsy.

A face EMG topography system was newly designed and manufactured by the authors. During mimetic actions, such as wrinkling the forehead, closing the eyes, blinking, grinning and blowing out the cheeks, EMG from 16 disk electrodes were concurrently recorded from the frontalis, orbicularis oculi, and orbicularis oris muscles on both sides. The EMG spike potentials fed to on-line computer processing were integrated and calculated with an interpolation formula in the computer, and the colour topographic figures derived from these calculations were displayed on CRT and printed out. These topograms were related to the amount of muscular activity. This technique was applied to 33 patients with Bell's palsy to document the degree and the time course of their mimetic dysfunction. The results obtained were reliable and reproducible. This technique will be useful as one of the proposed methods on grading of facial movement loss in clinical practice.

Adult↗
PubMed1987

Effects of dopamine on the secretion of glycoproteins from the functional segments of the rat submandibular gland.

The action of dopamine (DA) on salivation and the secretion of marker glycoproteins (GP) from secretory cells of the rat submandibular gland (SMG) was investigated using various blockers at doses of 1 or 2 mg/kg (i.v.). DA at doses from 5 to 40 mg/kg (i.p.) dose-dependently increased salivation and the concentration of protein in SMG saliva. The order of inhibitory potency on salivation was propranolol (PPR) greater than phentolamine (PHN) much greater than haloperidol (HAL) when DA was administered i.p. at a dose of 10 mg/kg and PHN much greater than HAL much greater than PPR when the dose of DA was 40 mg/kg. The concentration of protein in saliva after pretreatment with HAL or PHN increased significantly at a dose of 40 mg/kg of DA, but did not increase at a dose of 10 mg/kg of DA. Moreover, pretreatment with PPR decreased it at both doses of DA. The electrophoretic profiles of GP in DA-evoked saliva showed two characteristic main bands of GP I (130 KDa) and GP IV (21.5 KDa) contained in the acinar cells (AC) and a minor band of GP III (31 KDa) which originated from the granular tubular cells (GT). The profile was not changed by pretreatment with PHN and HAL when DA was administered at a dose of 10 mg/kg, but at a dose of 40 mg/kg, the intensity of band I increased. Pretreatment with PPR, when DA was administered at 40 mg/kg, caused an increase in the intensity of band III and a reduction in that of band I. These results suggest that DA, at low doses, affects the AC, whereas at a higher dose, it affects both the AC and GT.

Animals↗
PubMed1986

Effects of substance P on glycoprotein secretion from acinar cells of the rat submandibular gland.

The action of substance P on glycoprotein secretion from acinar cells of the rat submandibular gland was described in this report. Salivation elicited by i.v. injection of 0.5 to 20 micrograms/kg of substance P was increased dose-dependently, and its flow rate was highest at the first 1 min. Major glycoprotein species secreted into saliva by substance P-stimulus were shown to be electrophoretically identical with those found in acini, but not granular convoluted tubules. These results support the view that substance P acts on acinar cells of the submandibular gland and stimulates secretion of saliva from the cells.

Animals↗
PubMedDate not supplied

Synthesis and biological characterization of 1alpha,24,25-trihydroxy-2beta-(3-hydroxypropoxy)vitamin D(3) (24-hydroxylated ED-71).

24-Hydroxylated derivatives were synthesized in 24(R) and 24(S) forms by the convergent method as analogs related to 1alpha,25-dihydroxy-2beta-(3-hydroxypropoxy)vitamin D(3). In the convergent synthesis, the A-ring fragment, synthesized from diethyl D-tartarate, and the C/D-ring fragments in 24(R) and 24(S) forms (vitamin D numbering), obtained from vitamin D(2) via the Inhoffen-Lythgoe diol, were coupled in moderate yields to give 1alpha,24(R),25-trihydroxy-2beta-(3-hydroxypropoxy)vitamin D(3) and 1alpha,24(S),25-trihydroxy-2beta-(3-hydroxypropoxy)vitamin D(3). In preliminary biological evaluations, 24-hydroxylation of 1alpha,25-dihydroxy-2beta-(3-hydroxypropoxy)vitamin D(3) caused weakened affinity to vitamin D binding protein in vitro and less calcemic activity in vivo compared to the parent compound. While the affinity to vitamin D receptor in 24(R) epimer was sustained, the affinity in 24(S) epimer was less than that of the parent compound.

Animals↗
PubMedDate not supplied

Salivary secretion and histopathological effects after single administration of the muscarinic agonist SNI-2011 in MRL/lpr mice.

The salivary secretion and the histopathological effects after administration of a single dose of cis-2-methylspiro (1,3-oxathiolane-5,3') quinuclidine hydrochloride hemihydrate (SNI-2011) were monitored in adult, male and female MRL/lpr mice, C57BL/6J mice and ICR mice. SNI-2011 (1-10 mg/kg, i.p.), dose-dependently increased the secretion of saliva in MRL/lpr mice. The flow rate decreased gradually over the course of 60 min. The total volume of saliva, secreted in response to SNI-2011, was significantly higher in male than in female MRL/lpr mice, but there was no significant difference in this parameter between male and female C57BL/6J and ICR mice. Degeneration, apparent as atrophy and necrosis of serous cells in MRL/lpr mice, was reversed by treatment with SNI-2011 (3 and 6 mg/kg). These results suggest that SNI-2011 could be useful in the treatment of xerostomia in patients with Sjögren's syndrome.

Animals↗