Keratinization induced by air exposure in the reconstructed human epidermal model: an in vitro model of a cultured epithelial autograft.

A reconstructed human epidermis, an in vitro model of a cultured epithelial autograft, was used to examine the formation of a stratum corneum induced by exposure to air. A prolonged wet condition and excess application of petrolatum on the dressing reduced efficient production of the stratum corneum.

Teleost-type angiotensin is present in Australian lungfish, Neoceratodus forsteri.

Angiotensin I (ANG I) was produced from the incubation of lungfish plasma with homologous kidney extracts. The purified peptide was found to have the sequence of H-Asn-Arg-Val-Tyr-Val-His-Pro-Phe-Thr-Leu-OH, which is homologous for the first eight residues with all teleost angiotensins so far sequenced, although lungfish generally possess tetrapod-type hormones. The lungfish decapeptide (ANG I) induced dose-dependent increases in arterial pressure in the rat.

Tetrapod-type [Asp1] angiotensin is present in a holostean fish, Amia calva.

The renin-angiotensin system has been identified in various vertebrates, from elasmobranchs to mammals. Tetrapod (amphibians to mammals) angiotensin (ANG) has Asp at the N-terminus, but Asp is replaced by Asn in elasmobranch and teleost fish. ANG I has been isolated from incubates of plasma and kidney extracts of the bowfin Amia calva, a holostean fish, using the eel vasopressor activity as an assay system; its sequence was found to be H-Asp-Arg-Val-Tyr-Val-His-Pro-Phe-Asn-Leu-OH after sequence analysis, mass spectrometry, and comparison with the synthetic peptide.

A new natriuretic peptide isolated from cardiac atria of trout, Oncorhynchus mykiss.

Atrial and brain natriuretic peptides (ANP and BNP, respectively) are two cardiac natriuretic peptides (NPs) found in tetrapods from amphibians to mammals, whereas ANP and ventricular NP (VNP) have been identified in eel hearts. Because VNP has also been found in the rainbow trout ventricle, we attempted to isolate NP from trout cardiac atria in order to determine whether ANP and VNP are common cardiac NPs in teleosts. In the present experiments, we isolated VNP and a novel atrial NP consisting of 29 amino acid residues from the atria.

B-type natriuretic peptide isolated from frog cardiac ventricles.

A new natriuretic peptide with 27 amino acid residues has been isolated from cardiac ventricles of the bullfrog, Rana catesbeiana. Since this ventricular peptide had high sequence identity to B-type (brain) natriuretic peptide (BNP), especially to chicken BNP (74%), we named it bullfrog BNP. Thus, semi-aquatic amphibians have tetrapod-type BNP, but do not seem to have fish-type ventricular natriuretic peptide (VNP) in their ventricles.

Vasopressor activities of N-terminal fragments of adrenomedullin in anesthetized rat.

Adrenomedullin (AM) is a vasorelaxant peptide that was recently isolated from human pheochromocytoma. In contrast to human (h) AM, which has vasodepressor activity, a synthetic N-terminal fragment of hAM, hAM-(1-25)-NH2 showed vasopressor activity in the anesthetized rat. The N-terminal peptides hAM-1-31)-NH2, hAM-(1-25)-OH, hAM-(1-21)-NH2, acetyl-hAM-(16-21)-NH2, and acetyl-hAM-(16-36)-OH all showed vasopressor activities.

Smooth muscle relaxing and hypotensive activities of synthetic calciseptine and the homologous snake venom peptide FS2.

The biological activities of synthetic calciseptine and FS2, a homologous peptide from snake venom, were determined using in vitro and in vivo preparations. Calciseptine and FS2 produced dose-dependent relaxation in pre-constricted rat aorta, pulmonary artery and trachea. The onset and duration pattern of these relaxing effects were similar to those caused by nifedipine, an L-type Ca2+ channel blocker.

Rainbow trout ventricular natriuretic peptide: isolation, sequencing, and determination of biological activity.

Ventricular natriuretic peptide (VNP) is a new type of cardiac natriuretic peptide initially isolated from the eel ventricle. VNP has been isolated from cardiac ventricles of the rainbow trout, Oncorhynchus mykiss, and found to consist of 35 amino acid residues carrying a C-terminal tail sequence with 14 amino acid residues. Thus, the long C-terminal sequence characteristic of VNP was also conserved in the trout VNP.

The biological activity of endothelin-1 analogues in three different assay systems.

Endothelin (ET) is a vasoconstrictor peptide with 21-amino acid residues. In this study, we determined the relative potencies of ET-1 analogues to investigate the essential moiety of ET-1 for expression of its biological effect. We synthesized ET-1 analogues with the substitution of one amino acid at positions 2-18 and 21.