Two types of cells with central innervation in pineal gland of guinea pigs

Cells within pineal glands isolated from young, male guinea pigs were impaled with intracellular microelectrodes and their responses to stimulate the nerve supply to the gland were studied. Two types of cells were identified. The response of cells of type I was a depolarization on which spikes were superimposed. Blockers of alpha-adrenoceptors abolished the spikes while beta-adrenoceptor blockers reduced the depolarization to 27%, leaving a small tetrodotoxin-sensitive depolarization. After bilateral removal of the superior cervical ganglia (SCG) the beta-mediated depolarization was not observed while the spikes and the smaller depolarization persisted. The response of cells of type II was an initial large, transient depolarization followed by a smaller depolarization. Both components were reversibly blocked by tetrodotoxin. The only agents found to have any effect on these cells were oxytocin, vasopressin, and vasotocin. These peptides caused depolarization similar in amplitude to the larger response to nerve stimulation, although more prolonged. The large depolarization was not observed following ganglionectomy, but the smaller one persisted. It is concluded that cells of type I and II both receive inputs from nerves whose cell bodies lie in the SCG. Cells of both types are also innervated through another pathway.

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Cerivastatin induces type-I fiber-, not type-II fiber-, predominant muscular toxicity in the young male F344 rats

The Journal of Toxicological Sciences ◽

10.2131/jts.36.445 ◽

2011 ◽

Vol 36 (4) ◽

pp. 445-452 ◽

Cited By ~ 15

Author(s):

Hisakuni Obayashi ◽

Yoshikazu Nezu ◽

Hatsue Yokota ◽

Naoki Kiyosawa ◽

Kazuhiko Mori ◽

...

Keyword(s):

Young Male ◽

Type I ◽

Type Ii ◽

F344 Rats ◽

Male F344 Rats

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EXPERIMENTAL PNEUMONIA IN GUINEA PIGS

Journal of Experimental Medicine ◽

10.1084/jem.50.2.161 ◽

1929 ◽

Vol 50 (2) ◽

pp. 161-169 ◽

Cited By ~ 5

Author(s):

Julia T. Parker

Keyword(s):

Guinea Pigs ◽

Type I ◽

Type Ii ◽

Experimental Pneumonia ◽

Degree Of Protection ◽

Homologous Strain

1. Anti-pneumotoxic sera prepared in rabbits or horses by immunization with sterile filtrates of the pneumotoxin, under certain conditions protect against the pneumonia caused by the intratracheal injections of mixtures of living pneumococci and toxic autolysates. 2. The protection against the development of pneumonia is heterologous, at least as regards Type I, Type II, viz.: an anti-autolysate serum prepared by the immunization with a pneumotoxin from one type of pneumococcus will prevent the development of pneumonia caused by the injection of pneumococci and autolysate from another type. 3. Certain anti-pneumococcus horse sera used in the treatment of pneumonia in man, either contain no heterologous pneumonia-preventing antibodies or slight amounts only. These sera, however, protect against the pneumonia produced by injections of pneumococci and pneumotoxin of the homologous strain, the degree of protection depending on the amount of specific protective substances such sera contain. 4. Anti-pneumotoxic sera produced in rabbits or horses by the injection of sterile Berkefeld filtrates of the toxic autolysates contain no pneumococcus specific protective substances.

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cAPK mediates placental renin secretion stimulated by beta-adrenoceptor activation

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1994.267.6.e954 ◽

1994 ◽

Vol 267 (6) ◽

pp. E954-E960 ◽

Cited By ~ 1

Author(s):

G. J. Downing ◽

A. M. Poisner

Keyword(s):

Renin Secretion ◽

Type I ◽

Type Ii ◽

Basal Secretion ◽

Dependent Protein Kinase ◽

Catalytic Subunits ◽

Regulatory Subunits ◽

Beta Adrenoceptor ◽

Camp Generation ◽

Dependent Protein

Previous studies have indicated that activation of placental beta-adrenoceptors stimulates renin secretion, whereas basal secretion is extremely low. This response is potentiated by inhibition of types III and IV phosphodiesterases, implicating a role for adenosine 3',5'-cyclic monophosphate (cAMP). Described are experiments aimed at defining the regulatory influence of cAMP and cAMP-dependent protein kinase (cAPK) isotypes in renin secretion. Human placental explants were cultured with dobutamine, a beta 1-agonist, and cAPK activity, renin, and cAMP concentrations were determined. After 48 h of incubation, media concentrations of renin and cAMP increased and were positively correlated. Tissue cAPK activity was positively correlated with renin secretion associated with dobutamine. Renin secretion was measured in response to substituted cAMP analogues selective for a unique cAMP binding site (site A or B) for cAPK regulatory subunits. A fivefold stimulation of renin secretion by the type II site B activators occurred, whereas a threefold increase was seen with a type I site B analogue. Site A-selective analogues for cAPK types I and II produced no stimulation. Dobutamine-induced renin secretion was attenuated by selective inhibitors of cAPK regulatory and catalytic subunits. These findings indicate that placental renin secretion associated with beta-adrenoceptor activation is correlated with cAMP generation and mediated predominantly by the type II isoform of cAPK.

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Characterization of ectonucleotidase expression in the rat carotid body: regulation by chronic hypoxia

AJP Cell Physiology ◽

10.1152/ajpcell.00328.2016 ◽

2017 ◽

Vol 313 (3) ◽

pp. C274-C284 ◽

Cited By ~ 14

Author(s):

Shaima Salman ◽

Cathy Vollmer ◽

Grant B. McClelland ◽

Colin A. Nurse

Keyword(s):

Carotid Body ◽

Chronic Hypoxia ◽

Purinergic Signaling ◽

Sensory Nerve ◽

Nerve Fibers ◽

Type I ◽

Type Ii Cells ◽

Type Ii ◽

Sensory Plasticity ◽

Cervical Ganglia

The carotid body (CB) chemoreflex maintains blood Po2 and Pco2/H+ homeostasis and displays sensory plasticity during exposure to chronic hypoxia. Purinergic signaling via P1 and P2 receptors plays a pivotal role in shaping the afferent discharge at the sensory synapse containing catecholaminergic chemoreceptor (type I) cells, glial-like type II cells, and sensory (petrosal) nerve endings. However, little is known about the family of ectonucleotidases that control synaptic nucleotide levels. Using quantitative PCR (qPCR), we first compared expression levels of ectonucleoside triphosphate diphosphohydrolases (NTPDases1,2,3,5,6) and ecto-5′-nucleotidase (E5′Nt/CD73) mRNAs in juvenile rat CB vs. brain, petrosal ganglia, sympathetic (superior cervical) ganglia, and a sympathoadrenal chromaffin (MAH) cell line. In whole CB extracts, qPCR revealed a high relative expression of surface-located members NTPDase1,2 and E5′Nt/CD73, compared with low NTPDase3 expression. Immunofluorescence staining of CB sections or dissociated CB cultures localized NTPDase2,3 and E5′Nt/CD73 protein to the periphery of type I clusters, and in association with sensory nerve fibers and/or isolated type II cells. Interestingly, in CBs obtained from rats reared under chronic hypobaric hypoxia (~60 kPa, equivalent to 4,300 m) for 5–7 days, in addition to the expected upregulation of tyrosine hydroxylase and VEGF mRNAs, there was a significant upregulation of NTPDase3 and E5′Nt/CD73 mRNA, but a downregulation of NTPDase1 and NTPDase2 relative to normoxic controls. We conclude that NTPDase1,2,3 and E5′Nt/CD73 are the predominant surface-located ectonucleotidases in the rat CB and suggest that their differential regulation during chronic hypoxia may contribute to CB plasticity via control of synaptic ATP, ADP, and adenosine pools.

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Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067522 ◽

1970 ◽

Vol 28 ◽

pp. 106-107 ◽

Cited By ~ 1

Author(s):

Ronald S. Weinstein ◽

N. Scott McNutt

Keyword(s):

New Zealand ◽

General Hospital ◽

Massachusetts General Hospital ◽

Type I ◽

Type Ii ◽

Collaborative Effort ◽

Temperature And Pressure ◽

The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

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Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111367 ◽

1984 ◽

Vol 42 ◽

pp. 250-251

Author(s):

G. D. Gagne ◽

M. F. Miller ◽

D. A. Peterson

Keyword(s):

Endoplasmic Reticulum ◽

Experimental Infection ◽

Uranyl Acetate ◽

Type I ◽

Cellular Injury ◽

Type Ii ◽

Tubular Structures ◽

Type Iii ◽

Type Iv ◽

Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

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Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128274 ◽

1987 ◽

Vol 45 ◽

pp. 792-793

Author(s):

T.A. Fassel ◽

M.J. Schaller ◽

M.E. Lidstrom ◽

C.C. Remsen

Keyword(s):

Cytoplasmic Membrane ◽

Structural Features ◽

Methylotrophic Bacteria ◽

Type I ◽

Type Ii ◽

Membrane Complex ◽

Oxidation Of Methane ◽

Methane Oxidizing Bacteria ◽

Wall Structures ◽

Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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