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.

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.

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.

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.

New Calcitonin Isolated from the Ray, Dasyatis akajei.

Calcitonin causes hypocalcemia by inhibiting the resorption of calcium from the bone in mammals. Calcitonin has now been isolated from the ultimobranchial gland of a cartilaginous fish, the ray (Dasyatis akajei), and its amino acid has been determined to be H-Cys-Thr-Ser-Leu-Ser-Thr-Cys-Val-Val-Gly-Lys-Ser-Gln-Gln-Leu-His-Lys-Leu-G ln-Asn-Ile-Gln-Arg-Thr-Asp-Val-Gly-Ala-Ala-Thr-Pro-NH2. Although its basic structure is well conserved, the amino acid sequence of ray calcitonin is considerably different from that of other calcitonins sequenced to date.

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.

Development of a True Ovoviviparous Sea Star, Asterina pseudoexigua pacifica Hayashi.

Asterina pseudoexigua pacifica is a true ovoviviparous asteroid in that its development and metamorphosis occur within the spatial hermaphroditic gonad. From the middle of June to the middle of July, the gonad contains numerous embryos and juveniles in various stages through metamorphosis. The opaque, greenish yellow mature ovum is 450 μm in diameter.

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.

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.

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.

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.

Development and metamorphosis of the sea-star, Astropecten scoparius Valenciennes.

1. Astropecten scoparius develops to a bipinnaria with simple ciliary bands and short bipinnari arms through a wrinkled blastula by holoblastic, radial cleavage. 2.

ON THE DEVELOPMENT OF THE ULTIMOBRANCHIAL GLAND IN AN ANURAN, RANA JAPONICA JAPONICA.

The development of the ultimobranchial gland (UBG) was studied from its earliest emergence in Rana japonica japonica. UBG primordia appear at stage 22 as outfoldings of the pharyngeal epithelium of the 6th visceral pouch in both sides of the body. At stage 24, they separate from the pharyngeal wall, and then become follicular at stage 25.

CHANGES IN CALCIUM CONCENTRATIONS OF SERUM AND COELOMIC FLUID OF THE BULLFROG, RANA CATESBEIANA, DURING LARVAL DEVELOPMENT AND METAMORPHOSIS.

The serum calcium levels of bullfrog tadpoles (stage 26 to 33) and adults are higher than those of the coelomic fluid. The serum levels increase gradually from stage 26 (7.6 mg/100 ml) to stage 30 (8.