Histochemical and immunohistochemical studies on the origin of the blue marlin heater cell phenotype

The superior rectus muscle fibers of marlins, swordfish, sailfish and spearfish are modified for heat production at the expense of contractile ability. Although ‘heater cells’ are a muscle derivative (Bennett, 1971 and Block, 1991), the myoblast origin and developmental pathway of these thermogenic cells is unknown. To gain insight into heater cell origins, we characterized blue marlin superior rectus muscle and its heater tissue derivative with histochemical and immunological techniques. We specifically employed myosin ATPase and succinate dehydrogenase histochemical assays, and myosin heavy chain immunohistochemistry. Results revealed that marlin superior rectus muscles contain at least six distinct fiber types, and suggested the presence of both twitch and tonic fibers. Immunological results indicate that myosin is present within the thermogenic cells but not in myofibrillar lattices. The antibodies that recognized myosin in heater cells also labeled myosin in the twitch fibers of swimming muscle. In contrast, antibodies that labeled histologically defined tonic fibers did not label heater cells. These results suggest that heater cells and twitch fibers express the same myosin isoform, and establish a phenotypic connection between heater cells and twitch fibers. This conclusion is discussed in the context of the muscle-to-heater trajectory and the muscle fiber-type origin of heater cells.     

铝对大白鼠海马所致损害的实验研究

为探讨铝对海马的损害,用３０只健康大白鼠,体重２００～３００克,分为Ａ组（正常对照）１０只,Ｂ组（低铝组饲料中加５００ｍｇ／ｋｇＡｌＣｌ３）１０只,Ｃ组（高铝组饲料中加２５００ｍｇ／ｋｇ／ＡｌＣｌ３）１０只。分别饲养１２个月后,分组断头取脑海马,按组织化学及酶组织化学常规做“铝定性”反应,琥珀酸脱氢酶（ＳＤＨ）、乳酸脱氢酶（ＬＤＨ）、硫胺素焦磷酸酶（ＴＰＰａｓｅ）、镁激活三磷酸腺苷酶（Ｍｇ２＋－ＡＴＰａｓｅ）、胆碱酯酶（ＣｈＥ）测定。按电镜常规做超微结构的观察。结果提示：Ｃ组,海马ＳＤＨ、Ｍｇ２＋－ＡＴＰａｓｅ、ＣｈＥ活性明显减弱（由强阳性（）下降为阳性（＋）,铝反应增强（在海马的神经细胞内强阳性（）;同时海马神经元内线粒体嵴断裂、肿胀、空泡样变,神经纤维髓鞘变性（如不规则卷曲、松散）。说明铝对海马的功能与结构均有损害     

Occurrence of keratinization in the structures associated with lips of a hill stream fish Garra lamta(Hamilton)(Cyprinidae,Cypriniformes)

Keratinized regions were found to occur in the rostral cap, adhesive pad and horny jaw sheaths associated with the lips of Garra lamta, which inhabits fast flowing turbulent hill streams. In these structures, the surface epithelial cells were modified into characteristic keratinized spine‐like or columnar tooth‐like unculi, which would provide firm anchorage for the fish on the substratum and assist the fish in browsing or scraping food materials from it.     

Crustacean visual system: an investigation on glial cells and their relation to extracellular matrix.

Glial cells in higher invertebrate groups are usually recognized on the basis of their location and general morphological or functional criteria. In this study of the crustacean visual system, we have approached the analysis of the relations between glial cells and the extracellular matrix by classical histochemical methods for carbohydrates at the light and electron microscopic levels, carbonic anhydrase histochemistry and by the biochemical characterization of sulphated polysaccharides. Periodic acid-Schiff-positive glial cells and processes were observed in the retina, basement membrane below the retina and in the optic ganglia. Carbonic anhydrase was not detected in the retina but it was demonstrated in all optic ganglia. The biochemical analysis of the extracellular matrix confirmed the alcian blue reaction and showed that sulphated polysaccharides are not abundant in the optic neuropils. This article describes into more details the crustacean visual system glial cells classification, and the relation between them and the extracellular matrix. In addition, they show that glial cells are the main components of the retinal basement membrane.     

Sulphur, thiols, and disulphides in the fish epidermis, with remarks on keratinization

Energy dispersive x-ray (EDX) analysis and qualitative and quantitative histochemistry were applied to study the distribution and contents of sulphur, thiols and disulphides in the epidermis of the river lamprey Lampetra fluviatilis , the lesser spotted dogfish Scyliorhinus canicula and the brown trout Salmo trutta fario . Thiols generally reacted weakly throughout the entire epidermis, whereas disulphide reactions were more distinct and differentiated. In the river lamprey, the concentrations of -S-S- groups clearly increased in the developing mucous cells from the stratum basale to the stratum superficiale; skein cells and granular cells reacted negatively to weakly. In the lesser spotted dogfish, amounts of disulphides appeared at moderate concentrations, and only goblet cells displayed a strong reaction. In the brown trout, filament cells showed low concentrations or weak reactions of disulphides, goblet cells and the most outer superficial cells stained strongly. Sulphur distribution and contents generally supported the histochemical observations in normal epidermis cells (absolute sulphur contents: 41–59 mM), only the brown trout showed high amounts of sulphur in the stratum basale (81 mM). The findings corroborate the view that there is an inverse correlation between keratinization and mucous secretion in normal fish epidermis. The sometimes distinct contents of disulphides in the outer mucous layer indicate that this system could endure higher mechanical stress than predictable from its large amounts of neutral glycoproteins.     

Fine structure and fluorescence morphology of adrenergic nerves after 6-hydroxydopamine in vivo and in vitro

Summary In parallel fine structural, fluorescence histochemical and biochemical experiments the effect of 6-OH-DA administered in vivo and in vitro on the adrenergic nerves in the mouse iris was studied. As seen in the electron microscope, in vivo administration of 6-OH-DA causes a selective, rapid degeneration of the adrenergic axon terminals similar to that found after axotomy, whereas the cholinergic nerves are unaffected at all time intervals studied. Already 1 hr after the injection of 6-OH-DA the axonal enlargements swell and the size of the dense core of the granular vesicles is strongly reduced. Since the NA stores are almost completely depleted at this time interval, the small core present may be due to a reaction between 6-OH-DA and the fixative. From 2–4 hr after the injection increasing numbers of axonal enlargements with a high electron density are observed in the Schwann cell cytoplasm, which later are digested and completely absent about 48–72 hr after the 6-OH-DA injection. During the following weeks adrenergic axons reappear. This time course of degeneration obtained is considerably faster than that seen after axotomy in other studies. After incubation in 6-OH-DA containing media similar changes were observed in the axonal enlargements, starting already after 30 min of incubation. At this time-point there is a considerable reduction of endogenous NA and a severe damage of the membrane pump uptake mechanism. Incubation with 6-OH-DA and subsequent rinsing for 2 hr caused marked changes, including partly swelling of axons and partly shrinking of the axons into electron dense bodies.The fluorescence histochemical and biochemical results are in good agreement with the ultrastructural studies demonstrating a rapid loss of NA from the adrenergic nerve terminals and main axons and a long lasting depletion of the NA, with a gradual recovery to 75% 6 weeks after the injection.The investigation has been supported by research grants from the Swedish Medical Research Council (14X-2295, 14X-2887 and 04X-3881) Karolinska Institutet, Magnus Bergvalls and Carl-Berthel Nathorst Stiftelser. For generous supplies of drugs we are indebted to the following companies: AB Hässle (6-OH-DA, through Dr H. Corrodi), Pfizer (Niamid^®), Ciba (Serpasil^®). The skilful technical assistance of Miss Bodil Flock, Mrs Waltraut Hiort and Mrs Eva Lindqvist is gratefully acknowledged.     

Fluorescent histochemical studies on the effects of 6-hydroxydopamine on adrenaline-containing nerves in the toad

Summary Fluorescence histochemistry has been used to study the effects of 6-hydroxydopamine (6-OHDA) (100 mg/kg injected into the dorsal lymph sac) on adrenaline-containing nerves in the large intestine, mesentery, lung, bladder and heart atria of the toad Bufo marinus. A gradual decrease both in fluorescence intensity and in number of detectable fibres during the first 4 hours after 6-OHDA was accompanied by a build-up of fluorescence in the nonterminal regions. These phenomena have been discussed in relation to the time course of the degeneration produced by 6-OHDA in noradrenergic nerves of higher vertebrates. Almost complete chemical sympathectomy was seen after one day, and it was not till 13 days that regenerating nerve fibres were seen in any organ. In the large intestine, however, re-innervation was slower, being first noted after 39 days. The time course of regeneration has been compared with that following sympathectomy in various mammalian organs.     

Distribution of monoamine oxidase in the hippocampal region of the guinea pig

Summary 1. The distribution of monoamine oxidase (MAO) within the dentate area, a part of the hippocampal region, has been described for the adult guinea pig.2. The histochemical demonstration of the enzyme was done essentially according to the tryptamine-tetrazolium method of Glenner et al., and the staining reactivity was controlled by complete inhibition with iproniazide.3. Most of the MAO in the dentate area was present in a stratified pattern. Within the molecular layer, a supragranular third reacted heavily, while a more weakly staining superficial layer could be distinguished from an intermediate, still paler lamina. The granular cell bodies were unstained. In the hilus, five layers showing alternating stronger and weaker activity were observed. The distribution of the MAO staining was compared with conventional anatomical subdivision of the dentate region.4. The guinea pig dentate area appears to have a greater amount and more stratified distribution of MAO than the comparable region previously described in the rat.I am indebted to Mrs. E. Kjær Hansen, Mrs. L. Knudsen, Mr. A. Meier, Mr. Th. Nielsen, Mrs. K. Sørensen, and Miss M. Sørensen for skillful technical assistance. This study was supported in part by U.S.P.H.S. Grant NS 07998.