PubMed Health⌕ Search

Biomedical subjects

O Murakami

Publications and source records attributed to O Murakami.

122 records · Page 7Linked to original sources

Role of bovine albumin in a serum-free suspension cell culture medium.

A serum-free culture medium, supplemented with 1% bovine serum albumin, supported the growth of both primary and continuous suspension-type cultures of various mammalian tumor cells. The role of albumin added to the medium was also studied. Defatted albumin failed to support cell growth, unless reconstituted with its lipid extract. Similarly, defatted albumin when combined with oleic and linoleic acids, also supported cell growth. Therefore, albumin-bound fatty acids play an important growth-promoting role in serum-free medium.

Animals↗

Increases of neuropeptide Y-like immunoreactivity in plasma during insulin-induced hypoglycemia in man.

Neuropeptide Y-like immunoreactivity (NPY-LI) in plasma during insulin-induced hypoglycemia was measured in 4 healthy male volunteers. Plasma NPY-LI increased from 167 +/- 11 pg/ml to 247 +/- 25 pg/ml 30 min after the administration of insulin (0.1 U/kg body weight IV), reached the maximum (296 +/- 6 pg/ml) 45 min after the insulin, and then decreased. These results suggest that NPY is released into the systemic circulation during insulin-induced hypoglycemia in man.

Adult↗

Calcitonin gene-related peptide-like immunoreactivities in pheochromocytomas.

Calcitonin gene-related peptide (CGRP) is reported to exist in high concentrations in plasma and tumor tissues of medullary thyroid carcinomas. CGRP-like immunoreactivity (LI) in tumor tissues of pheochromocytomas was investigated by radioimmunoassay. CGRP-LI in 9 pheochromocytomas ranged from 0.50 to 1240 ng/g wet tissue. Sephadex G-50 column chromatography revealed that most of CGRP-LI in tumor extracts was eluted in an identical position to synthetic human CGRP. Reverse-phase high pressure liquid chromatography revealed that CGRP-LI in tumor extracts was eluted in an identical position to synthetic human CGRP and in a more hydrophobic position. These results indicate that high concentrations of CGRP-LI also exist in tumor tissues of pheochromocytomas.

Adrenal Gland Neoplasms↗

Porcine brain natriuretic peptide-like immunoreactivity in rat tissues.

The presence of immunoreactive porcine brain natriuretic peptide in rat tissues was studied with a specific radioimmunoassay for porcine brain natriuretic peptide-26. The cross-reactivity of the antiserum used was less than 0.001% with rat atrial natriuretic peptide, rat brain natriuretic peptide-32 and rat brain natriuretic peptide-45. Immunoreactive porcine brain natriuretic peptide was detectable in various tissues of the rat, and high concentrations of immunoreactive porcine brain natriuretic peptide were found in the brain and cardiac atrium, with the highest level in the hypothalamus (159 +/- 30 fmol/gram wet tissue, mean +/- SEM, n = 4). Reverse phase high performance liquid chromatography showed that the immunoreactive porcine brain natriuretic peptide of the whole brain and heart extracts eluted mainly at an identical position to synthetic porcine brain natriuretic peptide-26. These findings indicate that porcine brain natriuretic peptide-like substance, distinct from rat brain natriuretic peptide, is present in high concentrations in the rat brain and cardiac atrium.

Animals↗

Human brain natriuretic peptide-like immunoreactivity in human brain.

The presence of immunoreactive human brain natriuretic peptide in the human brain was studied with a specific radioimmunoassay for human brain natriuretic peptide-32. This assay showed no significant cross-reaction with human alpha atrial natriuretic peptide, porcine brain natriuretic peptide or rat brain natriuretic peptide. Immunoreactive human brain natriuretic peptide was found in all 5 regions of human brain examined (cerebral cortex, thalamus, cerebellum, pons and hypothalamus) (0.6-6.7 pmol/g wet weight, n = 3). These values were comparable to the concentrations of immunoreactive alpha atrial natriuretic peptide in human brain (0.5-10.1 pmol/g wet weight). However, Sephadex G-50 column chromatography showed that the immunoreactive human brain natriuretic peptide in the human brain eluted earlier than synthetic human brain natriuretic peptide-32. These findings suggest that human brain natriuretic peptide is present in the human brain mainly as larger molecular weight forms.

Aged↗

Pituitary adenylate cyclase activating polypeptide (PACAP)-like immunoreactivity in pheochromocytomas.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a novel hypothalamic peptide consisting of 38 amino acids [PACAP(1-38)] with a potent stimulatory action on adenylate cyclase in rat pituitary. The presence of immunoreactive (IR-) PACAP in the tumor tissue of pheochromocytomas was studied by radioimmunoassay and immunocytochemistry. The antibody to PACAP was raised in a rabbit injected with a peptide containing amino acids 28-38 of PACAP. This antibody showed no significant cross-reactivity with either PACAP(1-27) or vasoactive intestinal polypeptide. The tumor tissue concentrations of IR-PACAP(1-38) were 0.5-57.5 pmol/g wet weight (n = 13) (24.5 +/- 22.4 pmol/g wet weight, mean +/- SD), while those in the normal adrenal glands were 3.58 +/- 2.02 pmol/g wet weight (n = 7) and those in the adrenal cortical tumors were 5.58 +/- 2.02 pmol/g wet weight (n = 6). The IR-PACAP(1-38) concentrations in 7 out of 13 pheochromocytomas exceeded 18 pmol/g wet weight. Sephadex G-50 column chromatography revealed that the IR-PACAP(1-38) in extracts of pheochromocytomas eluted in both the positions of PACAP(1-38) and a larger molecular weight. Reverse-phase high performance liquid chromatography of the tumor extracts revealed a peak in the position of PACAP(1-38) and at least four other peaks. Immunocytochemistry of pheochromocytomas showed numerous immunoreactive cells. The immunostaining was abolished by absorption of the antiserum with synthetic PACAP(1-38). These findings indicate that multiple forms of IR-PACAP(1-38) are present in pheochromocytomas.

Adrenal Gland Neoplasms↗

Melanin-concentrating hormone in the human brain.

The presence of human melanin-concentrating hormone (MCH) was studied in the human brain by radioimmunoassay and immunocytochemistry. Immunoreactive MCH concentrations in the human brain ranged from 0.07 to 19.7 pmol/g wet weight. High performance liquid chromatography of the hypothalamus showed a large immunoreactive peak in the position of human/rat MCH, which was eluted 9 min later than that of salmon MCH. Free-floating sections (40 microns) of the hypothalamus were immunostained. Positive MCH immunostaining was found in perifornical, tuberomammillary, and posterior nuclei. Numerous MCH-immunoreactive nerve fibers were observed throughout the hypothalamus. The presence of high concentrations of MCH in the human brain, in particular in the hypothalamus, suggests that MCH is a neurotransmitter, a neuromodulator, or a neurohormone in man.

Aged↗