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J Koike

Publications and source records attributed to J Koike.

84 records · Page 5Linked to original sources
PubMed1988

Role of central serotonergic (5-HT2) receptor in blood pressure regulation in rats.

To investigate the role of the serotonergic nervous system in blood pressure regulation, 5 micrograms of 5-hydroxytryptamine (5-HT) was given i.c.v. before and after 1 microgram of i.c.v. xylamidine or 200 micrograms of i.c.v. ketanserin or 200 micrograms of i.v. ketanserin in conscious Wistar Kyoto rats. Also i.v. (0.5, 1, 2 micrograms) or i.c.v. (1 microgram) phenylephrine (PHE) were given before and after 1 microgram of i.c.v. xylamidine. I.c.v. 5-HT elicited a consistent pressor response of approximately 27mmHg and slight decrease in heart rate. MAP and heart rate did not change after xylamidine or ketanserin. Whereas pressor response to i.c.v. 5-HT after i.c.v. ketanserin or i.c.v. xylamidine was suppressed, it did not change after i.v. ketanserin. Neither i.c.v. nor i.v. PHE-induced pressor response was influenced by i.c.v. xylamidine pretreatment. These data suggest that the central 5-HT2 receptor may subserve pressor function in rats.

Amidines↗
PubMed1982

Restoration of oestrogen-positive feedback effect on LH release in women with prolactinoma by transsphenoidal surgery.

The effects of hyperprolactinaemia on the hypothalamo-pituitary axis by iv injection of 100 micrograms luteinizing hormone releasing hormone (LRH) in 7 women with prolactinoma before and 3 months after normalization of the Prl level by transsphenoidal surgery. A dose of 20 mg of conjugated oestrogen (Premarin) was also infected iv into patients with prolactinoma before and 4 months after surgery, and the serum LH levels were determined serially for 120 h after the injection. Surgical treatment caused significant reduction of the mean (+/- SE) serum prolactin (Prl) level from 123.3 +/- 7.8 to 19.4 +/- 5.6 ng/ml. But the differences in the basal levels of HL (11.3 +/- 2.2 to 8.6 +/- 1.5 mIU/ml), FSH (8.3 +/- 2.4 to 10.6 +/- 3.7 mIU/ml) and oestradiol (26.6 +/- 8.6 to 37.5 +/- 5.5 pg/ml) before and 4 months after surgery were not significant. An exaggerated LH response to LRH in untreated prolactinoma patients was also observed after surgical treatment. After surgical treatment, patients showed LH release with a peak between 48 and 72 h after the injection of Premarin, whereas before treatment they did not show any LH discharge. The mean percent increase in LH between 48 and 72 h was also significantly higher after operation than before operation. These results suggest that the hyperprolactinaemia in prolactinoma patients may cause an impaired positive feedback effect of oestrogen on LH release and that this derangement can be reversed by reduction of the Prl level by adenomectomy.

Adenoma, Chromophobe↗
PubMedDate not supplied

Productions of interferon-gamma and nitrite are induced in mouse splenic cells by a heteroglycan-protein fraction from culture medium of Lentinus edodes mycelia.

A xylose-rich heteroglycan-protein fraction (LAP1) was prepared from a solid culture medium in which Lentinus edodes mycelia were growing actively. Mouse splenic cells (SPs) were incubated with [3H]TdR in the presence of LAP1. The incubated SPs were fractionated into plastic adherent splenic cells (ADs), nylon-column effluent splenic cells (NEs) and sIg-expressed splenic cells (SIs), which are rich in Mac-1+, Thy-1.2+ and Ly-5+ cells, respectively. The incorporation of [3H]TdR in response to LAP1 was enhanced in each of the fractionated cell populations. Northern or dot blot hybridization showed that productions of IFN-gamma and its receptor mRNAs are induced predominantly in NEs. In another experiment, SPs were fractionated into ADs, NEs and SIs. Then, NE-AD, SI-AD and NE-SI mixtures were prepared and incubated in the same manner. A significant incorporation of [3H]TdR was shown only in the NE-AD mixture. The enzyme-linked immunosorbent assay showed that IFN-gamma production in response to LAP1 is induced in SPs or in the NE-AD mixture, but not in NEs alone. The level of the production was about 5 times higher in the mixture than in SPs after a 72 h incubation. Moreover, LAP1 was capable of inducing NO2- production in SPs. Thus, the present studies imply that this heteroglycan-protein fraction stimulates productions of IFN-gamma and nitrite in mouse splenic cells, augmenting antitumor immune response(s).

Animals↗
PubMedDate not supplied

Cerebral edema associated with craniectomy and arterial hypertension.

The present studies were performed to determine whether cerebral edema will develop as a consequence of arterial hypertension and/or craniectomy. Arterial hypertension was induced for 30 minutes by inflation of a balloon catheter situated in the descending aorta, and a parietal craniectomy was performed. The cerebral edema noticed was evaluated by macroscopic and microscopic observations, BBB permeability of HRP and Evans blue and water content. In addition, ICP was measured in the cisterna magna and ICPP by a catheter-tip transducer. In arterial hypertension or craniectomy alone, some small areas of Evans blue extravasation with increased water content were seen in the cortex, which corresponded to the occipito-parietal parts of the arterial boundary zones. In contrast, when arterial hypertension was combined with craniectomy, these lesions extended further into underlying white matter with increased water content. Forty-eight hours later, extensive brain edema with a shift of midline structures developed on the side of craniectomy which differed from that in arterial hypertension or craniectomy alone. It is suggested that some hydrostatic pressure gradients, particularly between blood vessel and surrounding extracellular space and among different areas within the brain parenchyma, may play an important role in the development of brain edema.

Animals↗