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C Oguro

Publications and source records attributed to C Oguro.

At least 19 recordsLinked to original sources
PubMed1993

Goldfish calcitonin: purification, characterization, and hypocalcemic potency.

A novel teleost calcitonin was isolated from the goldfish, Carassius auratus, and its amino acid sequence was determined to be H-Cys-Ser-Ser-Leu-Ser-Thr-Cys-Val-Leu-Gly- Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn-Val-Gly- Ala-Gly-Thr-Pro-NH2. The structure of goldfish calcitonin (gCT) was similar to that of salmon calcitonin (sCT) but differed from the latter at positions 3, 27, and 29. The hypocalcemic activity of gCT was estimated to be 3,470 IU/mg by the standardized rat bioassay method, compared with a value of 3,500 IU/mg for sCT. After administration of gCT to young goldfish, the serum Ca concentration was significantly lower in some cases than in controls. However, in other cases no such difference was recognized.

Amino Acid Sequence↗
PubMed1992

Calcitonin of the stingray: comparison of the hypocalcemic activity with other calcitonins.

Hypocalcemic potency of calcitonin isolated from the stingray (cartilaginous fish), Dasyatis akajei, was examined using the rat bioassay and compared with the activities of other calcitonins (human, pig, salmon, eel, and fowl). The potency of Dasyatis calcitonin (dCT) was estimated to be 1500-3800 IU/mg. However, when the duration of the hypocalcemic effect of dCT was taken into consideration, it was judged that dCT was approximately 2.4-6.2 times more potent than mammalian calcitonins, but about 2.3-3.5 times less active than other nonmammalian calcitonins.

Amino Acid Sequence↗
PubMed1991

Calcitonin-immunoreactive cells are present in the brains of some cyclostomes.

In the brains of four species of cyclostomes (two species each of lampreys and hagfishes), immunoreactive calcitonin-producing cells (iCT cells) were located immunohistochemically by the peroxidase-antiperoxidase method using anti-salmon calcitonin antiserum. In the case of both the adults and the ammocoetes of the brook lamprey (Lampetra reissneri) which lives in freshwater throughout its life, iCT cells were found in two distinct areas: in the pars ventralis hypothalami of the diencephalon and in the torus semicircularis of the mesencephalon. The iCT cells in the diencephalon are classified as bipolar nerve cells, and those in the mesencephalon are classified as multipolar nerve cells. In both the anadromous and catadromous arctic lamprey (Lampetra japonica), iCT cells were present only in the diencephalon, and those were bipolar nerve cells. There seemed to be no differences in the numbers and the immunostainability of the iCT cells, despite the different environments inhabited by the lampreys. In the hagfishes (Eptatretus burgeir and Paramyxine atami) that inhabit seawater throughout their lives, iCT cells were also found only in the diencephalon, although they were very few in number and exhibited poor immunostainability.

Animals↗
PubMed1991

Cells showing immunoreactivity for calcitonin or calcitonin gene-related peptide (CGRP) in the central nervous system of some invertebrates.

In the central nervous system of some species of several invertebrate phyla, including land planarians (Platyhelminthes), ribbon worms (Nemertina), slugs (Mollusca), polychaetes, earthworms and leeches (Annelida), pill bugs (Arthropoda), and beard worms (Pogonophora), salmon calcitonin-immunoreactive cells and rat calcitonin gene-related peptide (CGRP)-immunoreactive cells were found by immunohistochemistry. These immunoreactive cells were located in the region surrounding the neuropile, although the sizes of the cells varied according to species. Some of them were round or polygonal and regarded as apolar nerve cells because of their lack of cytoplasmic processes, whereas others were spindle-shaped or elongated, being comparable with unipolar nerve cells because of extension of their cytoplasmic processes in the direction of the neuropile. In some cases, it was noted that the cytoplasmic processes had complicated branches or formed loop-like structures at their ends. These observations suggest that a calcitonin-like or CGRP-like substance is extensively present in invertebrates as well as vertebrates.

Animals↗
PubMed1991

Involvement of prolactin in the regulation of plasma calcium levels in the newt, Cynops pyrrhogaster.

In the newt, Cynops pyrrhogaster, parathyroidectomy (PTX) brought about a marked decrease in the concentration of plasma calcium. The animals recovered from the hypocalcemia by 15 days after the operation if the pituitary gland was left intact. After PTX, no significant changes in the plasma sodium concentration were observed. Experiments were then conducted to obtain direct evidence that endogenous prolactin (PRL) is involved in this recovery process. Recovery of the calcium level after PTX was blocked by administration of an antiserum raised against newt PRL. In newts deprived of both the pituitary and parathyroid glands, no recovery from hypocalcemia was observed. Administration of newt or ovine PRL to parathyroidectomized-hypophysectomized newts significantly elevated the blood calcium level. After PTX, the concentration of immunoassayable PRL in the blood rose to 10 times the value in sham-operated animals. These results indicate the involvement of PRL in calcium homeostasis in newts with a shortage of parathormone.

Animals↗
PubMed1990

The crab-eating frog Rana cancrivora: serum mineral concentrations and histology of the ultimobranchial gland and the parathyroid gland.

In the crab-eating frog Rana cancrivora, taken from a full-strength seawater pond, the in situ levels of serum Na, Cl, K, Ca, Mg, Pi, urea, and osmolarity were examined. The levels were higher than those usually reported for freshwater anurans. However, values for the monovalent salts, urea, and osmolarity were lower than those reported by Gordon et al. (1961, J. Exp. Biol. 38, 659-678) following immersion of this species in 80% seawater for 7 days. The histological features of the ultimobranchial gland and parathyroid gland were coincident with those known in usual freshwater frogs, in spite of the peculiarity of the habitat of this species. The ultimobranchial gland was composed of a single follicle or multiple follicles. In most parenchymal cells, immunoreactive calcitonin was detected using the PAP method with anti-salmon calcitonin antiserum. In the parathyroid gland, cells in the central part of the gland were smaller than those in the peripheral part.

Animals↗
PubMed1984

Effects of anesthesia on the electrolyte concentrations in blood and coelomic fluid of the earthworm, Pheretima communissima.

Sodium, potassium, calcium and magnesium concentrations in blood and coelomic fluid of Pheretima communissima under various methods of anesthesia or in the unanesthetized condition were determined. All electrolyte concentrations determined in ethanol-anesthetized earthworms were not significantly different from those in unanesthetized earthworms. Thermal (warming, cooling) anesthesia, urethane and chloretone brought about increases or decreases in some electrolyte concentrations in the blood or coelomic fluid. However, not all electrolytes responded similarly to a method of anesthesia.

Anesthesia↗
PubMed1983

Hypocalcemic potency of the ultimobranchial gland in some urodelan amphibians.

The hypocalcemic potencies of the ultimobranchial glands of two urodelans, Onychodactylus japonicus and Hynobius nigrescens, were studied; according to the rat bioassay, their calcitonin values (MRC) were 30 and 18 mU/kg body wt, respectively. Various organs other than the ultimobranchial gland were also assayed in rats to see whether they had any hypocalcemic potency. However, the ultimobranchial gland was the only organ examined with detectable hypocalcemic potencies in these urodelans. The hypocalcemic potencies of urodelan ultimobranchial glands are one order lower than those reported in the other vertebrate classes, contrasting with the potencies of anuran ultimobranchial glands. The biological significance of this low potency is discussed.

Animals↗
PubMed1982

Urine calcium concentrations in bullfrog tadpoles kept in tap water or high calcium environment, with special reference to ultimobranchialectomy.

1. Urine calcium concentrations were determined in intact and ultimobranchialectomized bullfrog tadpoles kept in tap water (Ca: 8.5 and 19.7 mg/100 ml), urine calcium levels did not show significant increases. 3. In ultimobranchialectomized tadpoles, hypercalciuria concomitant with the rise in serum calcium levels in recognized under both conditions of high calcium water and tap water. 4. It was suggested that in bullfrog tadpoles ultimobranchial glands do not exert effective influences on the renal handling of calcium.

Acclimatization↗