Biomedical subjects

N Matsukawa

Publications and source records attributed to N Matsukawa.

30 records · Page 2Linked to original sources

PubMed1995

Accumulation of hippocampal cholinergic neurostimulating peptide (HCNP)-related components in Hirano bodies.

We have previously isolated from the hippocampus of young rats a novel peptide termed 'hippocampal cholinergic neurostimulating peptide' (HCNP) which specifically enhances the cholinergic activity of the septohippocampal system in vitro. Cloning and base sequence analysis of HCNP-specific cDNA from rat and human cDNA libraries revealed that the 1.1 kDa peptide aligns at the N-terminal region of its 21 kDa precursor protein. An affinity-purified rabbit antibody to rat HCNP prepared by us recognizes the C-terminal domain of the peptide, while an antibody against human HCNP binds to a large portion of the peptide. In this report we show that both antibodies react with HCNP-related components present in the soluble cytosol fraction of human brain tissue. Immunohistochemical examination of human nervous system tissues from elderly individuals revealed that Hirano bodies in Sommer's sector of the hippocampus were specifically stained by anti-HCNP antibodies. The number of HCNP-positive Hirano bodies was greater in patients with Alzheimer's disease than in normal, age-matched individuals. The immunohistochemical results were substantiated by immunoelectron microscopy. The present findings indicate that HCNP-related components accumulate in Hirano bodies, suggesting that patients who bear these inclusions may have a disturbance of the septo-hippocampal cholinergic system, considered to be of importance for learning and memory formation.

Aged↗

PubMed1994

Microvasculature of the lingual papillae in primates and insectivores--fungiform, vallate and foliate papillae.

The microvascular architecture of the fungiform, vallate and foliate papillae was investigated under scanning electron microscope in man, common squirrel monkeys, common marmosets, common tree shrews (primates), large Japanese moles and dwarf shrews (insectivores) utilizing microvascular corrosion casts. The fungiform papilla of the lingual apex in man was supplied by an intrapapillary capillary network with a globular pattern. It was composed of 10-15 capillary loops in a circular arrangement and 5-7 thick capillaries in the center. The fungiform papilla of the lingual body was supplied by a dense capillary network on the top and lateral surfaces. That in other primates was supplied by a cylindrical capillary network and loop formation was seen on the top surface. That in insectivores was supplied by a thin cylindrical network with coarse meshes, at the tips of which were observed 2 or 3 capillary rings in the mole and only one in the dwarf shrew. The vallate papilla in primates was supplied by an intrapapillary capillary network with a globular pattern, and showed irregularly tortuous capillary loops on its top surface. The vallum was supplied by a capillary network in man and usually one or two rows of loops arranged in a circle in other primates. The vallate papilla in insectivores was supplied by a doughnut-like capillary network with a recess on the top surface, and an indistinctly low vallum by a low undulating network. The foliate papillae were most developed in man, and each lobule was supplied by capillaries passing longitudinal to it and capillary loops in 5-10 regular rows on the top, but 3-5 rudimentary lobules in the squirrel monkey and marmoset. In the two species, each lobule was supplied by one arteriole, one venule and a coarse capillary network continuing from the interpapillary network. No foliate papilla was observed, but large conical papillae were noted in the tree shrew and insectivores. In conclusion, the intrapapillary vasculature appeared most complicated in man, simplified in the squirrel monkey and marmoset, and was much more simplified in the insectivores, where it was quite different from that in the primates. The pattern of the intrapapillary vasculature in the tree shrew was transitional between primates and insectivores.

Aged↗

PubMed1993

Dahl's salt-resistant normotensive rat has mutations in cytochrome P450(11 beta), but the salt-sensitive hypertensive rat does not.

Molecular cloning of cytochrome P450(11 beta) cDNAs from the adrenal glands of Dahl's salt-sensitive hypertensive (DS) and salt-resistant normotensive (DR) rats was performed using a combined technique of the first strand cDNA synthesis by reverse transcriptase followed by polymerase chain reaction. The cDNA sequence of P450(11 beta)-DS was identical to that of wild type P450(11 beta). In contrast, the clone obtained from the DR rat contained six nucleotide substitutions causing five amino acid alterations (Arg-127-->Cys, Val-351-->Ala, Val-381-->Leu, Ile-384-->Leu, and Val-443-->Met). When the two cDNAs were expressed in COS-7 cells and steroid conversion rates of the transformed cells were determined, a ratio of 18-hydroxylation to 11 beta-hydroxylation of 11-deoxycorticosterone by P450(11 beta)-DS-expressed cells was 0.58, whereas that by P450(11 beta)-DR-expressed cells was 0.23. Plasma levels of 18-hydroxy-11-deoxycorticosterone and corticosterone (the 11 beta-hydroxylation product of 11-deoxycorticosterone) in DS and DR rats well reflected the steroidogenic activities of the two P450s. These results suggest that the characteristic plasma steroid level of the DR rat is caused by the mutations in P450(11 beta) gene and may act to maintain the normotensive blood pressure in this rat strain during sodium loading.

Amino Acid Sequence↗

PubMed1993

Microvascular architecture of the filiform papillae in primates and insectivores.

The microvascular architecture of filiform papillae was investigated under a scanning electron microscope in man, Japanese monkeys, common squirrel monkeys, common marmosets, common tree shrews, large Japanese moles and dwarf shrews utilizing microvascular corrosion casts. Filiform papillae were circularly arranged in primates, and each of them was supplied by a hairpin capillary loop. These papillae sometimes were aggregated. The filiform papillae of Japanese monkeys exhibited markedly locational differences on the lingual dorsum and were supplied by circularly arranged capillary loops or by an intrapapillary capillary network. Small filiform papillae were located on an epithelial eminence in the lingual radix, each of them supplied by a low and simple hairpin capillary loop. The aggregated filiform papillae of common squirrel monkeys were less frequent without any locational differences. Low filiform papillae of common marmosets and tree shrews were simpler in form, being arranged in a circle and supplied by a simple hairpin capillary loop. The filiform papillae of insectivores were not arranged in a circle. The filiform papillae of dwarf shrews were supplied by an incomplete capillary ring without a loop. With respect to species differences, the circularly arranged capillary loops in man were most complicated and highly developed. Microvascular architecture of the filiform papillae of insectivores was much simpler, different from those observed in primates.

Animals↗

PubMed1991

Localization of the gene transcripts of 11 beta-hydroxylase and aldosterone synthase in the rat adrenal cortex by in situ hybridization.

Using in situ hybridization, localization of the gene transcripts of 11 beta-hydroxylase and aldosterone synthase was investigated in order to clarify the sites for the synthesis of corticosterone (glucocorticoid) and aldosterone (mineralocorticoid) in the rat adrenal cortex. The gene transcript of 11 beta-hydroxylase was localized in all the endocrine cells of the entire adrenal cortex, while that of aldosterone synthase was exclusively confined in zona glomerulosa cells. These results represent that every endocrine cell of all the cortical zones synthesizes 11 beta-hydroxylase which converts 11-deoxycorticosterone to corticosterone, and only glomerulosa cells synthesize aldosterone synthase which produces aldosterone from corticosterone. Thus it is clearly shown that zona glomerulosa cells synthesize mineralocorticoid, while zona fasciculata as well as reticularis cells produce glucocorticoid.

Adrenal Cortex↗

PubMed1991

Molecular nature of aldosterone synthase, a member of cytochrome P-450(11 beta) family.

The molecular nature of the aldosterone synthesizing enzymes of cattle and rat is discussed. In bovine adrenal cortex, one molecular species of cytochrome P-450(11 beta) catalyzes aldosterone synthesis as well as 11 beta-hydroxylation. The intactness of the mitochondrial membrane surrounding P-450(11 beta) in the zonae fasciculata-reticularis is essential to keep the aldosterone synthesizing activity of the cytochrome in these zones latent. In rat adrenal cortex, two distinct molecules belonging to a P-450(11 beta) family exist. One is 11 beta-hydroxylase, and the other aldosterone synthase.

Adrenal Cortex↗

PubMed1990

Molecular cloning and expression of cDNAS encoding rat aldosterone synthase: variants of cytochrome P-450(11 beta).

Two distinct forms of cDNA encoding rat aldosterone synthase were cloned from an adrenal capsular tissue cDNA library. The deduced amino acid sequences showed that one of the enzymes (P-450(11 beta),aldo-1) had a long extension peptide composed of 34 amino acid residues while the other (P-450(11 beta),aldo-2) had an extension peptide identical to that of rat P-450(11 beta). Glu at the 320th position of P-450(11 beta),aldo-1 was replaced with Lys in P-450(11 beta),aldo-2. The amino acid sequence of the aldosterone synthase was highly homologous (81%) to rat P-450(11 beta). Constructed expression vector containing the cDNA for extension peptide of P-450(11 beta) and the mature protein of P-450(11 beta),aldo-1 was transfected into COS-7 cells. The cells converted 11-deoxycorticosterone into corticosterone, 18-hydroxycorticosterone, and aldosterone.

Amino Acid Sequence↗

PubMed1990

[An experience of anesthesia in a case of WPW syndrome].

WPW (Wolff-Parkinson-White) syndrome is a rare disease characterized by electro-cardiographic anomalies associated with a history of recurrent supraventricular tachycardia. ECG abnormalities consist of a short PR interval and a broad QSR complex with a slurred upstroke. We experienced general anesthesia in a 29-year-old male with this syndrome for operation of maxillary cyst. Physical laboratory examinations of this patient revealed his conditions of within normal limits with the exception of ECG findings. After premedication with atropine, hydroxyzine and pethilorfan intramuscularly one hour prior to anesthesia, anesthesia was induced with intravenous thiopental 325 mg and the trachea was intubated with intravenous succinylcholine 40 mg. Thereafter anesthesia was maintained with 2.0% enflurane and 67% nitroxide in oxygen under controlled ventilation. During 1 hour operation, vital signs remained stable and paroxysmal tachycardia was not recognized on the ECG. The postoperative course was uneventful.

Adult↗

PubMed1990

[A case of general anesthesia with Pierre Robin syndrome and scoliosis].

We experienced a case of general anesthesia in a one-year-old boy for palate plasty with a slight micrognathia, cleft palate and scoliosis. At the first anesthesia, we tried two times oral intubation under the spontaneous respiration after slow induction with halothane, nitrous-oxide in oxygen, twice but were unsuccessful. In site of easy intubation with succinyl choline chloride rales and bronchial secretions increased and the operation was postponed. Ten months later, the same operation was planned and re-tried using same method as the first anesthesia. As this time, it was relatively easy to intubate, blood pressure and heart rate were stable during the operation. The recovery from anesthesia was smooth. From the experience of this case, we recognized again that preoperative respiration management was very important for these patients.

Anesthesia, Dental↗

PubMed1989

Molecular cloning and sequence analysis of cDNA encoding rat adrenal cytochrome P-450(11)beta.

A cDNA clone encoding cytochrome P-450(11)beta of rat adrenal has been cloned and sequenced using a bovine P-450(11)beta cDNA insert (pcP-450(11 beta)-2; (1987) J. Biochem. 102, 559-568) as a probe. The nucleotide sequence contains an open reading frame sufficient to encode the entire amino acid sequence of a P-450(11)beta precursor protein consisting of 499 amino acids including an extension peptide of 24 amino acids at the NH2-terminus. The cDNA contains 1247 nucleotides at the 3'-noncoding region including 51 nucleotides of poly A, but lacks the 5'-noncoding region. The deduced amino acid sequence shows 61% similarity to that of bovine P-450(11)beta. Putative binding sites for heme and steroid are highly conserved among steroidogenic P-450s of known structure.

Adrenal Glands↗

PubMedDate not supplied

Brain malformations caused by retroviral vector-mediated gene transfer of hippocampal cholinergic neurostimulating peptide precursor protein into the CNS via embryonic mice ventricles.

Hippocampal cholinergic neurostimulating peptide precursor protein (HCNP-pp) is a unique multifunctional protein, being not only the precursor of HCNP, which promotes the phenotype development of septo-hippocampal cholinergic neurons, but also the binding protein of phosphatidylethanolamine, ATP, Raf-1 kinase (known as "Raf-1 kinase inhibitory factor" in peripheral organs), and serine protease. We obtained a high-titer retroviral vector harboring HCNP-pp cDNA by the use of a modified packaging cell line and centrifugation, and by injecting it into embryonic mouse ventricles, we investigated the function of its gene product within the central nervous system (CNS). We found that efficient transduction into hippocampal pyramidal neurons can be achieved by injecting the vector into embryonic brain ventricles on embryonic day 14 (E14). Three days after receiving the intraventricular injection of the high-titer HCNP-pp retrovirus vector on E14, the tissues around the ventricles showed an overexpression of HCNP-pp. This was accompanied by a reduced amount of activated MEK and Erk (as analyzed by histochemical and Western blot methods), suggesting that HCNP-pp also regulates the MAP-kinase cascade within the CNS. Surprisingly, mouse brains that received the HCNP-pp retroviral vector showed massive malformation of the hippocampus and cerebellum when examined 30 days after birth. This shows that strictly regulated HCNP-pp gene expression is necessary for the normal development of the mouse brain, and that the moderate overexpression achieved by retroviral vector-mediated gene transfer is sufficient to cause severe abnormality of entire brain structures.

Animals↗

PubMedDate not supplied

Effect of aging on the renin angiotensin system in patients with renovascular hypertension.

The effect of aging on the renin angiotensin system (RAS) was studied in 30 patients with renovascular hypertension and 33 patients with essential hypertension. Plasma renin decreased with age in patients with renovascular hypertension and essential hypertension. However, in patients with renovascular hypertension, the change was not statistically significant. Plasma aldosterone concentration showed a tendency to decrease with age in both groups. Stimulated plasma renin activity and the net increase in plasma renin activity after captopril administration in patients with essential hypertension showed a significant decrease with age. In patients with renovascular hypertension, exaggerated response of renin secretion was observed in younger patients, but middle-aged and elderly patients did not demonstrate this hyper-responsiveness. The degree of decrease in blood pressure by administration of an angiotensin (Ang) II analog ([Sar1,Ile8] Ang II) was the same in both younger and elderly patients with either disease. These results suggest that the effect of aging on the RAS occurs not only in patients with essential hypertension, but also in patients with renovascular hypertension. Furthermore, although the Ang II analog infusion test and captopril stimulation test are considered to be useful screening tests for renovascular hypertension, we consider that the combination of Ang II analog test and captopril test may be favorable to screen renovascular hypertension, since the captopril stimulation test had a lower sensitivity in younger (under 35 years old) patients.

Adult↗