scholarly journals Studies on the Queensland Lungfish, Neoceratodus forsteri (Krefft).

1965 ◽  
Vol 13 (2) ◽  
pp. 243 ◽  
Author(s):  
GC Grigg
Keyword(s):  
Smooth Muscle ◽  
Buccal Cavity ◽  
Vascular Supply ◽  
Respiratory Organ ◽  
Blood Capillaries ◽  
Air Space ◽  
Lower Oxygen ◽  
Lower Oxygen Level ◽  
The Right ◽  
Respiratory Medium

The lung of Neoceratodus forsteri consists of a single elongated sac dorsal to the gut and attached firmly along the dorsal mid-line in the region of the vertebral column. It communicates with the gut through the pneumatic duct which opens ventrolaterally via the glottis, on the right side of the pharynx. The embryological origin of the lung as a ventral outgrowth from the gut is reflected in the marked similarity between their tissues, and in the unusual configuration of the duct and blood vessels. Internally, the lung is divided into compartments formed by septa resulting from infolding of the walls. These compartments are further subdivided to form a spongy alveolar region. In this region of increased surface area run blood capillaries in proximity to the respiratory medium, close enough to allow gaseous exchange with it. Filling the lung is accomplished by a buccal force-pump, as in Amphibia, consisting of the hyoid apparatus and the muscular walls of the buccal cavity. Exhalation of air is effected by contraction of the smooth muscle components of the lung, assisted by its natural elasticity provided by elastin fibres present in both connective tissue and smooth muscle. The structure of the lung, its spongy walls, vascular supply with capillaries close to the air space, open pneumatic duct, regular exchange of air at the surface of the water, and the ability of the fish to survive out of water if kept moist, all point to the function of the lung as a respiratory organ. This is borne out by lung-gas analyses which consistently show lower oxygen level compared with air.

scholarly journals Histology of the trachea and lung of Siphonops annulatus (Amphibia, Gymnophiona)

2000 ◽  
Vol 60 (1) ◽  
pp. 167-172 ◽  
Author(s):  
B. KUEHNE ◽  
L. C. U. JUNQUEIRA
Keyword(s):  
Smooth Muscle ◽  
Gas Exchange ◽  
Connective Tissue ◽  
Smooth Muscle Cells ◽  
Respiratory Epithelium ◽  
Mucous Cells ◽  
Blood Capillaries ◽  
Surfactant Activity ◽  
Variable Morphology ◽  
The Right

The structure of the trachea and lung of Siphonops annulatus was studied in ten specimens of routinely fed animals. The trachea is constituted mainly by incomplete cartilage rings lined by a respiratory epithelium (ciliated and mucous cells) with variable morphology according to the region observed. A rich vascularization of this organ suggests its participation in blood-air gas exchange. The right lung in this species is developed and the left one is atrophied. This organ is constituted mainly by longitudinal septa formed by connective tissue, smooth muscle cells and blood capillaries. These structures are covered by pneumocytes of one type only, which present cytoplasmic particles that have been related with surfactant activity described in the lung of Gymnophiona.

scholarly journals Contractile and Endothelium-Dependent Dilatory Responses of Cerebral Arteries at Various Extracellular Magnesium Concentrations

1991 ◽  
Vol 11 (1) ◽  
pp. 161-164 ◽  
Author(s):  
Mária Faragó ◽  
Csaba Szabó ◽  
Eörs Dóra ◽  
Ildikó Horváth ◽  
Arisztid G. B. Kovách
Keyword(s):  
Smooth Muscle ◽  
Vascular Reactivity ◽  
Calcium Influx ◽  
Cerebral Arteries ◽  
Inhibitory Effect ◽  
Contractile Responses ◽  
Middle Cerebral Arteries ◽  
The Right ◽  
Endothelial Receptor

To clarify the effect of extracellular magnesium (Mg2+) on the vascular reactivity of feline isolated middle cerebral arteries, the effects of slight alterations in the Mg2+ concentration on the contractile and endothelium-dependent dilatory responses were investigated in vitro. The contractions, induced by 10−8-10−5 M norepinephrine, were significantly potentiated at low Mg2+ (0.8 m M v. the normal, 1.2 m M). High (1.6 and 2.0 m M) Mg2+ exhibited an inhibitory effect on the contractile responses. No significant changes, however, in the EC50 values for norepinephrine were found. The endothelium-dependent relaxations induced by 108–10−5 M acetylcholine were inhibited by high (1.6 and 2.0 m M) Mg2+. Lowering of the Mg2+ concentration to 0.8 m M or total withdrawal of this ion from the medium failed to alter the dilatory potency of acetylcholine. The changes in the dilatory responses also shifted the EC50 values for acetylcholine to the right. The present results show that the contractile responses of the cerebral arteries are extremely susceptible to the changes of Mg2+ concentrations. In response to contractile and endothelium-dependent dilatory agonists, Mg2+ probably affects both the calcium influx into the endothelial and smooth muscle cells as well as the binding of acetylcholine to its endothelial receptor. Since Mg2+ deficiency might facilitate the contractile but not the endothelium-dependent relaxant responses, the present study supports a role for Mg2+ deficiency in the development of the cerebral vasospasm.

scholarly journals THE ABSORPTION OF PROTEIN SOLUTIONS FROM THE PULMONARY ALVEOLI

1937 ◽  
Vol 66 (4) ◽  
pp. 449-458 ◽  
Author(s):  
Cecil K. Drinker ◽  
Madeleine Field Warren ◽  
Margaret MacLanahan
Keyword(s):  
Thoracic Duct ◽  
Horse Serum ◽  
Molecular Size ◽  
The Other ◽  
Immunological Methods ◽  
Protein Solutions ◽  
Blood Capillaries ◽  
Egg Albumin ◽  
Pulmonary Alveoli ◽  
The Right

Horse serum, crystallized hemoglobin, and crystallized egg albumin have been injected into the lung alveoli of dogs in which the entrances of the right lymphatics have been tied and the thoracic duct cannulated. Samples of blood and lymph have been taken following this injection. Only after several hours in the case of the horse serum and hemoglobin have these proteins been detected by immunological methods and invariably they have appeared first in the blood. Egg albumin also enters the blood capillaries, but much more rapidly than the other two proteins, due probably to the smaller molecular size.

Morphological signs of neurogenic inflammation in the heart of rats during aging

2022 ◽  
pp. 831-840
Author(s):  
Е.И. Чумасов ◽  
Е.С. Петрова ◽  
Д.Э. Коржевский
Keyword(s):  
Neurogenic Inflammation ◽  
Plasma Cells ◽  
Nerve Fibers ◽  
Blood Capillaries ◽  
Pgp 9.5 ◽  
Sympathetic Nerve Fibers ◽  
Close Relationship ◽  
The Right ◽  
Inflammatory Infiltrates ◽  
Heart Apparatus

С помощью гистологических методов окраски толуидиновым синим, гематоксилином и эозином и иммуногистохимических реакций на белок PGP 9.5, тирозингидроксилазу (ТГ), белок Iba-1, изучены клеточные изменения в разных отделах сердца крыс линии Wistar в возрасте 18- 23 мес. В соединительной ткани основания сердца обнаружены очаговые воспалительные инфильтраты, внутри которых выявлены PGP 9.5 и ТГ сплетения, состоящие из парасимпатических и симпатических нервных волокон. В области клапанного аппарата, на границе фиброзного кольца и миокарда правого предсердия, обнаружены патологические изменения нервных структур - дегенерация нервных пучков и зернистый распад варикозных аксонов терминального сплетения. Установлены тесные взаимоотношения аксонов терминальной нервной сети с клетками воспалительных инфильтратов и кровеносными сосудами. Определены закономерности встречаемости в различных отделах миокарда у старых животных нейроклеточных воспалительных комплексов, состоящих из нервных волокон, кровеносных капилляров и клеток-участников местного воспалительного процесса (тучных клеток, макрофагов, фибробластов, плазмоцитов). Установлен хронический характер нейрогенного воспаления в сердце при старении. Using histological methods of staining with toluidine blue, hematoxylin-eosin and immunohistochemical reactions for the PGP 9,5 protein, tyrosine hydroxylase (TH), Iba-1 protein, cellular changes in different parts of the heart of Wistar rats at the age of 18-23 months were studied. In the connective tissue of the heart base, focal inflammatory infiltrates were found, near which PGP 9.5 and TH plexuses, consisting of parasympathetic and sympathetic nerve fibers, were detected. In the area of the valvular heart apparatus, at the border of the anneau fibreux and the myocardium of the right atrium, pathological changes in nerve structures were found: degeneration of nerve fibers and granular destruction varicose axons of the terminal plexus. A close relationship has been established between axons of the terminal nervous network and cells of inflammatory infiltrates and blood capillaries. The features of the localization of neurocellular inflammatory complexes consisting of nerve fibers, blood capillaries and cells participating in the local inflammatory process (mast cells, histiocytes, monocytes, fibroblasts, plasma cells) in various parts of the myocardium in old animals are described. The chronic nature of neurogenic inflammation in the heart during aging has been established.

Functional anatomy of the vagal innervation of the cervical trachea of the dog

2000 ◽  
Vol 89 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Robert L. Coon ◽  
Patrick J. Mueller ◽  
Philip S. Clifford
Keyword(s):  
Smooth Muscle ◽  
Vagus Nerve ◽  
Neural Control ◽  
Muscle Tone ◽  
Cuff Pressure ◽  
Vagal Innervation ◽  
Cervical Trachea ◽  
The Right ◽  
Left Vagus ◽  
Stimulation Of

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea. After establishment of tracheal tone, as indicated by increased cuff pressure, either the right or left vagus nerve was sectioned followed by section of the contralateral vagus. Sectioning the right vagus first resulted in total loss of tone in the cervical trachea, whereas sectioning the left vagus first produced either a partial or no decrease in tracheal tone. After bilateral section of the vagi, cuff pressure was recorded during electrical stimulation of the rostral end of the right or left vagus. At the maximum current strength used, stimulation of the left vagus produced tracheal constriction that averaged 28.5% of the response to stimulation of the right vagus (9.0 ± 1.8 and 31.6 ± 2.5 mmHg, respectively). In conclusion, the musculature of cervical trachea in the dog appears to be predominantly controlled by vagal efferents in the right vagus nerve.

scholarly journals Left Atrial Myxoma Hypervascularized from the Right Coronary Artery: An Interesting Cath Lab Finding

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
Marcos Danillo Peixoto Oliveira ◽  
Adriano Ossuna Tamazato ◽  
Fernando Roberto de Fazzio ◽  
Luiz J. Kajita ◽  
Expedito E. Ribeiro ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Right Coronary Artery ◽  
Left Atrial ◽  
Rare Case ◽  
Vascular Supply ◽  
Atrial Myxoma ◽  
Cardiac Tumors ◽  
Left Atrial Myxoma ◽  
The Right ◽  
Primary Cardiac Tumors

Primary cardiac tumors are rare and approximately half of them are atrial myxomas. They rarely remain asymptomatic, especially if large. The imaging of a myxoma by contrast dye during coronary angiography is an infrequent sign, which clarifies the vascular supply of the tumor. We report herein an interesting and rare case of a left atrial myxoma hypervascularized from the right coronary artery.

Extracellular calcium-dependent and -independent effects of adenosine in bovine coronary artery

1990 ◽  
Vol 68 (5) ◽  
pp. 608-613 ◽  
Author(s):  
Mudumbi V. Ramagopal ◽  
S. Jamal Mustafa
Keyword(s):  
Smooth Muscle ◽  
Coronary Artery ◽  
Coronary Arteries ◽  
Extracellular Calcium ◽  
Free Medium ◽  
Response Curves ◽  
Coronary Smooth Muscle ◽  
Calcium Dependent ◽  
Relaxation Responses ◽  
The Right

Adenosine relaxes the coronary arteries of various species through A2 receptors. The aim of the present investigation was to evaluate the relaxing effects of adenosine in relation to the role of calcium in bovine coronary arteries by studying the vasodilatory effect of adenosine in normal and calcium-free medium and on calcium-45 efflux into calcium-free medium. Acetylcholine (ACh) and norepinephrine (NE) were used to induce tone in coronary artery rings. Adenosine, 5′-(N-ethylcarboxamido)adenosine (NECA), and N6-(L-phenylisopropyl)adenosine (L-PIA) produced concentration-dependent relaxations of the coronary artery rings. Both in normal and calcium-free medium, the order of potency for adenosine analogs (NECA > L-PIA > adenosine) was similar and 8-phenyltheophylline antagonized the relaxation responses to adenosine and its analogs. Removal of extracellular calcium shifted the concentration–response curves to the right in a parallel fashion, slowed the rate of relaxation, and in NE contracted rings reduced the maximum responses for adenosine and its analogs. In calcium-free medium, adenosine was without an effect on calcium-45 efflux in the presence of ACh. However, adenosine inhibited the stimulated calcium-45 efflux induced by NE. The data suggest that the vasodilatory action of adenosine in bovine coronary smooth muscle has both extracellular calcium-dependent and -independent components.Key words: adenosine receptors, calcium, coronary circulation, vascular smooth muscle, acetylcholine, norepinephrine.

scholarly journals Expression of α-smooth muscle actin in the periodontal ligament during post-emergent tooth eruption

2018 ◽  
Vol 46 (6) ◽  
pp. 2423-2435
Author(s):  
Domna Dorotheou ◽  
Marie-Luce Bochaton-Piallat ◽  
Catherine Giannopoulou ◽  
Stavros Kiliaridis
Keyword(s):  
Smooth Muscle ◽  
Periodontal Ligament ◽  
Smooth Muscle Actin ◽  
Root Apex ◽  
Tooth Eruption ◽  
Muscle Actin ◽  
Adult Rats ◽  
Time Points ◽  
Male Wistar Rats ◽  
The Right

Objective This study was performed to explore the expression of α-smooth muscle actin (α-SMA) in the periodontal ligament (PDL) of young and adult rats during post-emergent tooth eruption in opposed and unopposed teeth at two time points: 3 and 15 days after antagonist loss. Methods Four-week-old (n = 20) and 22-week-old (n = 20) male Wistar rats were used. The right maxillary molar crowns were cut down. PDL samples were isolated from the first mandibular molars at two time points: 3 and 15 days after cut-down of the right maxillary molars. Quantitative reverse-transcription polymerase chain reaction and immunohistochemical staining were performed to detect differences in α-SMA expression in the PDL tissues of unopposed versus opposed molars. Results α-SMA was upregulated in the PDL of the unopposed molars in the 3-day group of young rats. The region around the root apex of the unopposed molars in this group exhibited strong immunostaining for α-SMA. The expression level and immunoreactivity of α-SMA did not differ in both time points in young controls and among all the adult groups. Conclusion α-SMA-positive myofibroblasts are implicated in post-emergent tooth eruption of unopposed molars of young animals.

Abstract 4572: Reduced Cardiac Progenitors in the Right Ventricle of Cyanotic Heart Lesions: Insights into RV Adaptation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Naila Mahmut ◽  
Caroline Kinnear ◽  
Megan Thompson ◽  
Patrick Shannon ◽  
David Chitayat ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Later Life ◽  
Capillary Density ◽  
Vascular Endothelial ◽  
Cardiac Progenitors ◽  
The Right ◽  
Von Willebrand ◽  
Endothelial Growth Factor ◽  
Left Heart Syndrome ◽  
Heart Lesions

The RV in hypoplastic left heart syndrome (HLHS) and Tetralogy of Fallot (TOF) is exposed to hypoxia and abnormal load which may lead to RV dysfunction despite surgical repair. The ability of hypoxia to upregulate angiogenic signaling in the RV is not known. We measured vascular endothelial growth factor (VEGF) mediated regulation of cardiac progenitors in the RV of patients with HLHS and TOF. Methods: RV myocardial samples were obtained from 6 pts with HLHS (age 0.96±1.5 yrs), 6 pts with TOF (age 3.5±6.3 yrs) and 9 age-matched controls with structurally normal hearts (age 0.16±0.3 yrs) at surgery/transplant/autopsy. The following were measured: VEGF, thymosin β-4 (recruits progenitors), Nkx2.5 (myocyte precursor), Flk-1 (smooth muscle progenitor), CD34 (endothelial progenitor), and von willebrand factor (vWf) (endothelial marker). Results: (i) VEGF and thymosin β-4 expression was lower in HLHS vs controls. This was associated with reduced cardiac progenitors and lower myocardial capillary density vs controls (0.14±0.01 vs 0.55±0.16, p<0.05). (ii) VEGF expression was preserved but thymosin β-4 was reduced in RV in TOF. This was associated with preserved myocyte progenitors but reduction in endothelial and smooth muscle lineages and reduced capillary density vs controls (0.13±0.03 vs 0.55±0.16, p<0.05) (Figure 1 ). Conclusion: Hypoxia fails to induce an angiogenic response in the RV in cyanotic heart lesions. This may be due to reduced VEGF (HLHS) or impaired coupling of VEGF to thymosin β-4 (TOF). This maladaptation may contribute to post-operative RV dysfunction and lower RV regenerative capacity in later life. Figure 1: Reduced capillary density (red) in HLHS and TOF

Physiological and pharmacological response of canine bronchial smooth muscle in situ

1983 ◽  
Vol 54 (1) ◽  
pp. 215-224 ◽  
Author(s):  
S. G. Hendrix ◽  
N. M. Munoz ◽  
A. R. Leff
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Maximal Response ◽  
Repeated Injection ◽  
Third Order ◽  
Bronchial Smooth Muscle ◽  
Pure Nitrogen ◽  
Parasympathetic Ganglion ◽  
The Right

We studied the isometric response of bronchial smooth muscle in a single third-order bronchus of 24 dogs in situ. Length-tension studies were performed in six dogs by repeated injection of 10(-5) mol acetylcholine (ACh) into the right bronchoesophageal artery, and the resting tension (30.6 +/- 6.9 g/cm) and length (0.76 +/- 0.14 cm) permitting maximal contraction were determined. In eight other dogs, dose-related bronchial contraction was obtained with 10(-10) to 10(-5) mol intra-arterial (ia) ACh. Supramaximal electrical stimulation of the right cervical vagus nerve and bronchial parasympathetic ganglion stimulation with ia 1–1-dimethyl-4-phenylpiperazinium (DMPP) also caused bronchial contraction. The maximal response to ia ACh (28.5 +/- 1.7 g/cm), supramaximal electrical stimulation (15.2 +/- 1.1 g/cm), and ia DMPP (10.5 +/- 3.0 g/cm) was blocked by an ia dose of atropine (1–5 micrograms/kg) that did not alter the sympathetic relaxation response in the trachea. In four dogs, the bronchial response to sympathetic activation was studied by intravenous (iv) bolus injection of DMPP after cholinergic blockade with atropine. DMPP (25 micrograms/kg iv) caused 9.5 +/- 2.2 g/cm bronchial relaxation, which was blocked completely by 2–4 mg/kg iv propranolol. In six other dogs, hypoxia induced by ventilation with pure nitrogen caused bronchial contraction, which was blocked by vagotomy, atropine, and hexamethonium. We report a sensitive method for selective measurement of bronchial smooth muscle response in a single resistance bronchus. This preparation preserves regional innervation and circulation and permits selective physiological stimulation in situ.

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