The lagena (the third otolith endorgan in vertebrates)

In this review, the structure and functions of the lagena (the third otolith organ) in an evolutionary lineage of the vertebrates are described and discussed. The lagenar macula appears first in the posterior part of the sacculus of elasmobranchs; in these animals, the lagena is considered to be involved in the balance support (orientation with respect to the gravitation force). The lagena as a separate endorgan has been described in teleost fishes; in some species, the lagena is connected with the sacculus, while in other species the interrelations of these structures can be dissimilar. The lagena supplements the functions of the sacculus; in fishes (animals with no special organ of hearing), it is involved in discrimination of sound oscillations, identification of the gravitation vector, and orientation in the course of movements within the vertical plane. In amphibians, the lagena is localized in the posterior part of the sacculus, near the auditory structures; it performs mostly vestibular and (to a much lesser extent) auditory functions. In amniotes, the lagena was first separated from the sacculus; it is localized in the cochlear canal, distally with respect to the hearing organ. Information on the functions of the lagena in amniotes is rather limited and contradictory. Central projections of this organ have been examined practically only in birds. Lagenar afferents project to the vestibular nuclei and cerebellum, while some fibers come to the auditory nuclei of the medulla. The lagena in birds can be related to their navigation abilities (birds are supposed to be capable of orienting within the magnetic field of the Earth due to the magnetic properties of the lagenar otoconia; this structure can also provide detection of movements along the vertical axis. The close proximity between the otolithic and auditory endorgans in the cochlear canal of amniotes can be indicative of the functional significance of these interrelations. This aspect, however, remains at present undiscovered. In mammals (except Monotremata), there is no lagena as an independent endorgan. Neirofiziologiya/Neurophysiology, Vol. 40, No. 2, pp. 160–178, March–April, 2008.     

The cellular composition of the blood and haematopoietic organs of turbot Scophthalmus maximus L.

The cellular composition of the blood, anterior kidney, spleen and thymus of turbot Scophrhalmus maximus L., aged 1 + was determined. Ninety-four per cent of blood cells belonged to the erythrocyte lineage of which 82% were mature erythrocytes. The leucocytes, which represented 4.5% of the blood cells, were mainly lymphocytes (50%). The presence of crythroblasts in the anterior kidney and the spleen demonstrated an erythropoietic activity in both organs. However, this activity appeared to be prevalent in the spleen which also appeared to act as a storage zone for erythrocytes and as the centre point for thrombopoiesis. Although 96% of the anterior kidney cells were leucocytes, the number of white cells per gram of organ was higher in the spleen.     

Floral-specific polypeptides of the Japanese morning glory

Polypeptides from stems, leaves, sepals, corollas, stamens and pistils of the Japanese morning glory (Ipomoea nil Roth (Pharbitis nil Chois.)) were separated by one- and two-dimensional gel electrophoresis and visualized by silver staining. The majority of polypeptides were expressed in two or more organs, while those specific to only one organ were comparatively rate. Among the polypeptides of the former class were two which appeared to be floral-specific. A 46-kDa (kilodalton) polypeptide was expressed in corollas, stamens and pistils, whereas a 32-kDa polypeptide was observed only in extracts prepared from reproductive organs. Polypeptide spots from the various organs were compared with those from leaves, and it was found that sepals and stems shared 40–50% of their polypeptides with leaves, whereas corollas, stamens and pistils shared 20% or less. The latter organs shared 120 polypeptides or roughly 15% of those identified in the floral extracts. Floralorgan-specific polypeptides comprised nearly 10% of the total floral polypeptides identified.Abbreviations kDa kilodalton - PAGE polyacrylamide gel electrophoresis - SDS sodium dodecylsulfate     

Distribution of neurotensin-like immunoreactivity in rat and cat area postrema

The distribution of neurotensin-like immunoreactive (NT-LI) fibers and cell bodies in the area postrema (AP) of rat and cat, utilizing the peroxidase, antiperoxidase (PAP) technique, is described. In the rat, the greatest accumulation of NT-LI fibers were present along the borders of the AP, while there were very few NT-LI fibers in central regions. In the cat, scattered NT-LI fibers occupied the majority of the central AP, while moderate numbers of NT-LI fibers were present at the ventromedial border. In more rostral cat AP levels, the number of NT-LI fibers decreased. NT-LI somata were present in rat AP, but were lacking in cat AP. The localization of NT within the AP suggests that the cardiovascular and gastric effects attributed to NT may be mediated, in part, through the AP.     

The fate of intraperitoneally injected carbon particles in cyprinid fish

Summary The lymphoid organs of rosy barb (Barbus conchonius) and carp (Cyprinus carpio) were investigated for their phagocytic uptake of carbon, after its intraperitoneal injection. Carbon handling was similar in both species. It was first detected in the lymphoid organs at 30 min after injection. During the first day, carbon was phagocytized by macrophages situated in the spleen within the ellipsoids and in the red pulp. In head and trunk kidney, carbon was found in macrophages scattered throughout the haemopoietic parenchyma, and in cells lining the blood sinuses. In the spleen, macrophages replete with carbon left the ellipsoidal structures and formed aggregates with pigment-containing macrophages from day 6 onwards. In all lymphoid organs, almost all carbon was ultimately concentrated in the melano-macrophage centres.     

Intra- and extraganglionic peripheral cholinergic neurons in the urogenital organs of the cat

Summary The distribution of cholinergic neurons in the urinary tract and male genital organs of the cat was studied by a histochemical method for acetylcholinesterase. In addition to cell clusters in autonomic ganglia (intraganglionic cells), isolated extraganglionic cholinergic cells were found within the innervated tissues, usually in association with nerve trunks and blood vessels. Smaller neural cells with multiple axonal processes, identical to Cajal's interstitial cells, were found in the meshes of the terminal nerve plexus in smooth muscle, lamina propria and vascular wall.It is concluded that peripheral cholinergic neurons, like their adrenergic analogues, are arranged as a short intraganglionic, a shorter extraganglionic, and a terminal system of neurons.Supported in part by grants 10465 and 11285 from the USPHS and the Henry C. Buswell Urology Research Fund.     

Immunocytochemical study of seminal γ-glutamyltransferase using monoclonal antibodies

We produced three monoclonal antibodies, SG1, SG2 and SG3, specific for human seminal -glutamyltransferase when characterized by enzyme-linked immunosorbent assay and immunoblotting. Seminal -glutamyltransferase was localized, by immunostaining, to the epithelial cells of the ductus epididymidis, seminal vesicle and prostate gland with SG1, those of the prostate gland with SG2, and those of the seminal vesicle with SG3. Rabbit polyclonal anti-seminal -glutamyltransferase serum reacted with the proximal convolution of the kidney and the bile capillaries of the liver, and with the epithelial cells of the reproductive organs. However, immunoreactivity was not observed in the kidney or liver with the monoclonal antibodies. Thus, these monoclonal antibodies are probably all specific to seminal -glutamyltransferase but recognize different epitopes.     

Poly(ethylene oxide)-grafted thermoplastic membranes for use as cellular hybrid bio-artificial organs in the central nervous system

Poly(acrylonitrile-co-vinyl chloride) (PAN/VC) anisotropic membranes were chemically modified with poly(ethylene oxide) (PEO) (5000 and 20,000 g/mol) by one of two aqueous reactions: (a) acid hydrolysis of the nitrile group to a carboxylic acid with which amine-terminated PEO (PEO-NH(2)) reacted or (b) base reduction of the nitrile group to an amine with which PEO-succinimide (PEO-SC) reacted. Approximately 1.3% of the bulk material was modified with PEO-NH(2) whereas 1.8 to 3.5% was modified with PEO-SC as determined by proton nuclear magnetic resonance ((1)H NMR) and attenuated total reflectance Fourier transform infrared (ATR FTIR) spectra. Approximately 50 to 75% less bovine serum albumin (BSA) adsorbed to PEO-grafted single skin fibers than to unmodified PAN/VC. Transport properties of modified and unmodified fibers were compared by passive diffusion, convective nominal molecular weight cutoff, and hydraulic permeability. Neither hydraulic permeability nor nominal molecular weight cutoff of BSA changed appreciably after surface modification with PEO indicating that pore structure was not adversely affected by the chemistry involved in grafting poly(ethylene oxide). However, in the absence of any membrane conditioning, the apparent diffusion of alpha-chymotrypsinogen (24,000 g/mol) was enhanced in PEO-grafted PAN/VC fibers possibly as a result of reduced sorption of the permeating protein. In vivo biocompatibility in the brain tissue of rats was judged by histological assessment of the host's cellular response to fibers implanted for 30 days; biocompatibility of both PAN/VC and PAN/VC-g-PEO was satisfactory but improved slightly with PEO grafting. (c) 1994 John Wiley & Sons, Inc.     

Localization of Drug-Metabolizing Enzyme Activities to Blood-Brain Interfaces and Circumventricular Organs

Abstract: The brain, with the exception of the choroid plexuses and Circumventricular organs, is partially protected from the invasion of blood-borne chemicals by the specific morphological properties of the cerebral micro-vessels, namely, the tight junctions of the blood-brain barrier. Recently, several enzymes that are primarily involved in hepatic drug metabolism have been shown to exist in the brain, albeit at relatively low specific activities. In the present study, the hypothesis that these enzymes are located primarily at blood-brain interfaces, where they form an "enzymatic barrier," is tested. By using microdissection techniques or a gradient-centrifugation isolation procedure, the activities of seven drug-metabolizing enzymes in isolated microvessels, choroid plexuses, meningeal membranes, and tissue from three Circumventricular organs (the neural lobe of the hypophysis, pineal gland, and median eminence) were assayed. With two exceptions, the activities of these enzymes were higher in the three Circumventricular organs and cerebral microvessel than in the cortex. Very high membrane-bound epoxide hydrolase and UDP-glucuronosyltransferase activities (approaching those in liver) and somewhat high 7-benzoxyre-sorufin- O -dealkylase and NADPH-cytochrome P-450 reductase activities were determined in the choroid plexuses. The pia-arachnoid membranes, but not the dura matter, displayed drug-metabolizing enzyme activities, notably that of epoxide hydrolase: The drug-metabolizing enzymes located at these nonparenchymal sites may function to protect brain tissue from harmful compounds.