Capillaria (Hepatocapillaria) cichlasomae sp. п., parasitic in the liver of the cichlid Cichlasoma urophthalmus (Günther) from a small freshwater lake ("aguada") Xpoc in Yucatan, Mexico, is described. The parasite is characterized mainly by its small body size (male 1.8 mm, female 4.5 mm), the structure of the stichosome (markedly short stichocytes in one row) and the male (the presence of a pair of small subventral postanal papillae) and female (anus distinctly subterminal) caudal ends, and by the size and structure of the spicule (spicule 0.068-0.085 mm long, with marked transverse grooves on surface) and eggs (size 0.053-0.058 x 0.023 mm, with protruding polar plugs). This is the second known Capillaria species from the liver of fish and the first one from the liver of a freshwater fish.
Two species of the genus Baruscapillaria Moravec, 1982 are known to parasitise the small intestine of the common cormorant, Phalacrocorax carbo (L.): Baruscapillaria carbonis (Dubinin et Dubinina, 1940) and B. rudolphii Moravec, Scholz et Našincová, 1994. A redescription of the former species, based on specimens collected from common cormorants shot in South Bohemia, Czech Republic, is provided. Morphological features distinguishing B. carbonis and B. rudolphii are specified. B. carbonis is characterised mainly by the well-developed membranous bursa in the male, composed of five distinct lobes (four lateral and one spur-shaped dorsal); the length of the spicule is 1.9-2.3 mm; gravid females are provided with a long vulvar appendage. Males of B. rudolphii have reduced, bi-lobed membranous bursa and the spicule is 0.9-1.3 mm long; the vulvar appendage is absent in gravid females. This is the first record of B. carbonis in the Czech Republic.
A new capillariid nematode, Capillostrongyloides morae sp. n., is described from specimens collected from the stomach and intestine of the common mora, Mora moro (Risso), and the Mediterranean codling, Lepidion lepidion (Risso) (both Gadiformes, Moridae), off the Mediterranean coasts of Spain. The new species shows similar morphological features as other congeneric species occurring in freshwater and marine fishes, but it differs in the length of the body and spicules, the size of the caudal bursa, and the presence of an elevated anterior vulvar lip. Capillostrongyloides morae sp. n. is the second species within the genus for which the presence of a stylet is reported, and the first one in which this structure along with the distribution of cephalic papillae and oral structures (e.g. lips and lobes) are clearly shown by using scanning electron microscopy.
Membrane currents induced by capsaicin (CAPS) in cultured sensory neurons from 1- to 2-day-old rats were studied. Responses to CAPS (lO^M) exceeding 1 nA at -50 mV were found in smaller, usually bipolar or tripolar neurons in which GABA (30 yuM) induced small or no response. Large, unipolar neurons, which exhibited large responses to GABA, were completely insensitive to CAPS (10//M). In contrast to GABA, responses to CAPS exhibited a slow rise and slow decay and a marked tachyphylaxis after repeated CAPS applications at high concentrations which made it difficult to study the concentration-response relationship. In partially run-down neurons, which exhibited quasi stable responses, the slope of the ascending phase was concentration-dependent with an apparent association rate constant Ki 9x104 [M-1s-1]. The time constant of the decay was 3.5 s, and was concentration-independent. However, in 5 neurones the EC50 measured from the first series of CAPS applications at increasing concentrations was 0.31 ±0.5ptA with a Hill coefficient 1.66±0.35. The responses to CAPS reversed at +10.4±2.5 mV suggesting that the current is carried nonselectively by monovalent cations and Ca2+. The channel conductance of CAPS-gated channels at -50 mV calculated from the mean membrane current and variance of the current noise in outside-out patches or measured directly was 28 pS (n=5). It is suggested that the CAPS-gated channels are either controlled by receptors with a very high affinity or that the channels are controlled by membrane-bound protein(s) which do not depend in their function on the supply of GTP or other intracellular metabolites.
Capsazepine is a competitive antagonist of capsaicin, a TRPV1 agonist responsible for the spicy taste of pepper. TRPV1 agonists and antagonists are known to affect mammalian body temperature, but their action on thermoregulation in insects is poorly known. In this study we evaluated the effect of capsazepine on the thermal preference of the American cockroach, Periplaneta americana using a thermal gradient. Our results revealed that capsazepine in submicromolar concentrations induces a preference for higher ambient temperatures when compared to the control insects. To assess whether capsazepine may act also as an antagonist of capsaicin in insects, we determined this insects' thermal behaviour when capsazepine was applied before capsaicin. The hypothermic response to capsaicin was clearly blocked by pre-treatment with capsazepine only in female American cockroaches. Our results indicate the involvement of structures functionally similar to TRPV1 in insect thermosensation., Justyna Maliszewska, Eugenia Tęgowska., and Obsahuje bibliografii
The effect of the angiotensin converting enzyme (ACE) inhibitor, captopril, on proteosynthesis in the aorta, acetylcholine-stimulated aortic relaxation and endothelaemia (circulating endothelial cells) was investigated in rabbits with aortic insufficiency. The animals were studied 28 days after experimental intervention. Cardiac volume overload stimulated proteosynthesis in the aorta as reflected by increased ribonucleic acid (RNA) concentration and [14C] leucine incorporation into proteins of the aorta. Moreover, the number of endothelial cells in the blood was increased. The administration of captopril starting from the second day of the haemodynamic overload, partially prevented the increase both in aortic proteosynthesis and in endothelaemia. Despite these alterations, the relaxing ability of the aorta to acetylcholine was not changed either by the haemodynamic overload or by captopril. We conclude that the increase of proteosynthesis in the aorta and of endothelaemia in the early period of chronic cardiac volume overload in rabbits were partially prevented by chronic captopril treatment. Neither aortic insufficiency nor captopril changed the acetylcholine-induced relaxation of the aorta.