scholarly journals Fetal Medial Habenula Transplants: Innervation of the Rat Interpeduncular Nucleus

1989 ◽  
Vol 1 (2) ◽  
pp. 57-62
Author(s):  
Nicholas J. Lenn ◽  
P. John Seeley ◽  
Pauline M. Field ◽  
Geoffrey Raisman
Keyword(s):  
Colloidal Gold ◽  
Third Ventricle ◽  
Donor Age ◽  
Adult Rats ◽  
Interpeduncular Nucleus ◽  
The Third ◽  
Medial Dorsal ◽  
Medial Habenula ◽  
The Difference

The effects of donor age and site of placement on the survival of fetal medial habenula (MH) transplants into adult rats hosts were examined. The innervation of the interpeduncular nucleus (IPN) in such cases was also examined. Explants of MH consisting of the medial-dorsal lip of the third ventricle were heldin vitrofor 1—2 days. Colloidal gold conjugated to wheat germ agglutinin was added for the last 18 hours to label the cells. Four of 16 cases with E19 derived transplants contained donor neurons. Markedly larger transplants were present in 95% of 20 cases with E16 derived transplants. Sites in the ventral midbrain were successful, while limited or no survival occurred at sites more remote from IPN. Retrograde labeling of transplant neurons was present in each case studied with HRP injection into host IPN. Colloidal gold-labeled macrophages, some oriented capillaries and GFAP-positive processes marked the donor-host interface. In EM the interface was evident only by the difference in tissue elements in the transplant versus host. Numerous synapses of Gray types I and II were present in the transplant. Excellent survival of MH neurons, donor/host interfaces, innervation of IPN by the transplant and fine structure in and around the transplants, all suggest that such preparations are suitable for further experimental analysis of the habenulo-interpeduncular system.

Central site for pressor action of blood-borne angiotensin in rat

1980 ◽  
Vol 239 (3) ◽  
pp. R358-R361 ◽  
Author(s):  
G. D. Fink ◽  
J. R. Haywood ◽  
W. J. Bryan ◽  
W. Packwood ◽  
M. J. Brody
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Angiotensin Ii ◽  
Pressor Response ◽  
Third Ventricle ◽  
Central Component ◽  
The Third ◽  
Electrolytic Lesions ◽  
The Central Nervous System ◽  
The Difference

A previous study demonstrated that the threshold dose of intra-arterial angiotensin II required to induce a pressor response in the rat was significantly lower when the drug was administered into the carotid artery than when administered into the abdominal aorta. This result was interpreted to indicate that part of the increase in arterial pressure produced by low concentrations of blood-borne angiotensin in this species was the result of an effect on structures in the central nervous system selectively accessible via the carotid vascular bed. The purpose of the present study was to establish more precisely the site of the pressor action of angiotensin within the central nervous system. The central component of the pressor effect of angiotensin was quantified as the difference in pressor responses to intracarotid and intra-aortic infusions of angiotensin II (delta c-a). In conscious rats, delta c-a was attenuated by administration of the angiotensin antagonist, saralasin, into the third cerebral ventricle. In rats with chronic electrolytic lesions of the anteroventral third ventricle (AV3V), delta c-a was abolished. Periventricular structures surrounding the third ventricle appear to mediate the central component of the pressor action of blood-borne angiotensin in the rat.

scholarly journals Classical and Membrane-Initiated Estrogen Signaling in an In Vitro Model of Anterior Hypothalamic Kisspeptin Neurons

Endocrinology ◽  
2015 ◽  
Vol 156 (6) ◽  
pp. 2162-2173 ◽  
Author(s):  
Melinda A. Mittelman-Smith ◽  
Angela M. Wong ◽  
Anupama S. Q. Kathiresan ◽  
Paul E. Micevych
Keyword(s):  
Positive Feedback ◽  
Intracellular Signaling ◽  
Third Ventricle ◽  
Reproductive Function ◽  
Estrogen Signaling ◽  
The Third ◽  
Periventricular Area ◽  
Estrogen Positive Feedback

Abstract The neuropeptide kisspeptin is essential for sexual maturation and reproductive function. In particular, kisspeptin-expressing neurons in the anterior rostral periventricular area of the third ventricle are generally recognized as mediators of estrogen positive feedback for the surge release of LH, which stimulates ovulation. Estradiol induces kisspeptin expression in the neurons of the rostral periventricular area of the third ventricle but suppresses kisspeptin expression in neurons of the arcuate nucleus that regulate estrogen-negative feedback. To focus on the intracellular signaling and response to estradiol underlying positive feedback, we used mHypoA51 cells, an immortalized line of kisspeptin neurons derived from adult female mouse hypothalamus. mHypoA51 neurons express estrogen receptor (ER)-α, classical progesterone receptor (PR), and kisspeptin, all key elements of estrogen-positive feedback. As with kisspeptin neurons in vivo, 17β-estradiol (E2) induced kisspeptin and PR in mHypoA51s. The ERα agonist, 1,3,5-Tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole, produced similar increases in expression, indicating that these events were mediated by ERα. However, E2-induced PR up-regulation required an intracellular ER, whereas kisspeptin expression was stimulated through a membrane ER activated by E2 coupled to BSA. These data suggest that anterior hypothalamic kisspeptin neurons integrate both membrane-initiated and classical nuclear estrogen signaling to up-regulate kisspeptin and PR, which are essential for the LH surge.

Norepinephrine inhibition of pulsatile LH release: receptor specificity

1986 ◽  
Vol 250 (2) ◽  
pp. E205-E211 ◽  
Author(s):  
H. Bergen ◽  
P. C. Leung
Keyword(s):  
Third Ventricle ◽  
Adult Rats ◽  
Beta Adrenergic ◽  
The Third ◽  
Ovx Rats ◽  
Adrenergic Blocker ◽  
Propranolol Treatment ◽  
Lh Release ◽  
Adrenergic Blockers ◽  
Infusion Of Norepinephrine

Infusion of norepinephrine (NE) into the third ventricle of ovariectomized (OVX) adult rats inhibits pulsatile luteinizing hormone (LH) secretion. This study examines the effects of pretreatment with specific alpha- and beta-adrenergic blockers on the subsequent NE-induced suppression of LH release. Unanesthetized long-term OVX rats were injected ip or iv with phenoxybenzamine (alpha-adrenergic receptor blocker), propranolol (beta-adrenergic blocker), or an equal volume of saline (as controls). Approximately 1-1.5 h later, the animals were given an intraventricular (ivt) administration of NE. Infusion of acidified saline into the third ventricle of OVX rats failed to affect the pulsatile pattern of LH release characteristic of these animals. After ivt of NE, the control rats showed a significant decrease in mean blood LH level of ca. 30%. Pretreatment of OVX rat with propranolol either ivt or ip failed to affect pulsatile LH release. Subsequent ivt infusion of NE either at 1 h or 15 min after propranolol treatment also caused a 28-30% decrease in the mean LH levels and suppressed pulsatile discharge of LH, an effect that lasted for approximately 45-50 min. In sharp contrast to the saline and propranolol-treated groups, rats pretreated with phenoxybenzamine had sporadic or no LH pulses during the 70-min postphenoxybenzamine period and had significantly lower mean LH levels when compared with control animals (P less than 0.05). Moreover, a drop in mean blood LH levels after NE infusion was not observed in the rats pretreated with phenoxybenzamine.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Role of the Ventricular System in Neuroendocrine Processes: Synthesis and Distribution of Thyrotropin Releasing Factor (TRF) in the Hypothalamus and Third Ventricle

1974 ◽  
Vol 1 (1) ◽  
pp. 74-84 ◽  
Author(s):  
K.M. Knigge ◽  
S.A. Joseph ◽  
D. Schock ◽  
A.J. Silverman ◽  
M.C.H. Ching ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Glutamic Acid ◽  
Median Eminence ◽  
Arcuate Nucleus ◽  
Third Ventricle ◽  
The Third ◽  
Hypothalamic Tissue ◽  
In Vitro Biosynthesis

SUMMARYIn vitro biosynthesis of thyrotropin releasing factor (TRF) by different regions of the hypothalamus of mink was examined. Homogenates of hypothalamic tissue were incubated in Krebs-Ringer medium containing 200 mg% glucose, 10-5M ATP, 0.1 mM histidine and glutamic acid and 0.15 μ c 3H-proline (40 Cilmmol) per mg. tissue. Extraction, purification and estimation of 3H-TRF biosynthesis involved several steps of charcoal extraction, carboxymethylcellulose and sephadex chromatography. 3H-TRF was synthesized throughout the entire antero-posterior extent of the hypothalamus in its dorsal and medial portions. 3H-TRF was synthesized also in a more discreet region, the arcuate nucleus. In vitro biosynthesis of 3H-TRF was stimulated significantly by thyroxine, but not by TSH, estradiol, corticosterone or melatonin. A method is described for collection of cerebrospinal fluid of the third ventricle of the rat brain; TRF concentration in this fluid was approximately in normal animals.The distribution of TRF-producing cells in the hypothalamus and presence of TRF in cerebrospinal fluid of the third ventricle is discussed with respect to the hypothesis that this releasing factor may be delivered to the median eminence and adenohypophysis in part, via the cerebrospinal fluid.

scholarly journals Saflufenacil (Kixor™): Biokinetic Properties and Mechanism of Selectivity of a New Protoporphyrinogen IX Oxidase Inhibiting Herbicide

Weed Science ◽  
2011 ◽  
Vol 59 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Klaus Grossmann ◽  
Johannes Hutzler ◽  
Guenter Caspar ◽  
Jacek Kwiatkowski ◽  
Chad L. Brommer
Keyword(s):  
Enzyme Activity ◽  
Weak Acid ◽  
Weed Species ◽  
The Third ◽  
Black Nightshade ◽  
Shoot Tissue ◽  
The Difference ◽  
Root Treatment ◽  
Acid Character

Saflufenacil (Kixor™) is a new protoporphyrinogen IX oxidase (PPO) inhibiting herbicide for preplant burndown and selective PRE dicot weed control in multiple crops, including corn. The biokinetic properties and the mechanism of selectivity of saflufenacil in corn, black nightshade, and tall morningglory were investigated. After root treatment of plants at the third-leaf stage, the difference in the phytotoxic selectivity of saflufenacil in corn and the weed species has been quantified as approximately 10-fold. The plant species showed similar selectivity after foliar applications; the plant response to saflufenacil was approximately 100-fold more sensitive compared with a root application. PPO enzyme activity in vitro was inhibited by saflufenacil, a 50% inhibition lay in a concentration range from 0.2 to 2.0 nM, with no clear differences between corn and the weed species. Treatments of light-grown plants and dark-grown seedlings with [14C]saflufenacil revealed that the herbicide is rapidly absorbed by root and shoot tissue. The [14C]saflufenacil was distributed within the plant systemically by acropetal and basipetal movement. Systemic [14C]saflufenacil distribution can be explained by the weak acid character of saflufenacil and its metabolic stability in black nightshade and tall morningglory. Metabolism of [14C]saflufenacil in corn was more rapid than in the weeds. In addition, low translocation of root-absorbed [14C]saflufenacil in the corn shoot was observed. It is concluded that rapid metabolism, combined with a low root translocation, support PRE selectivity of saflufenacil in corn.

On the Role of Transferrin in 67Ga Uptake by Tumor Cells

1988 ◽  
Vol 27 (04) ◽  
pp. 151-153
Author(s):  
P. Thouvenot ◽  
F. Brunotte ◽  
J. Robert ◽  
L. J. Anghileri
Keyword(s):  
Specific Binding ◽  
Subcellular Fractionation ◽  
Animal Blood ◽  
Tumor Bearing ◽  
Cell Structures ◽  
The Difference ◽  
Sarcoma Cells ◽  
In Vitro Uptake

In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about ii/io of 67Ga and 1/5o of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences

Increased Protein Synthesis by Human Platelets during Phagocytosis of Latex Particles in Vitro

1976 ◽  
Vol 35 (02) ◽  
pp. 350-357 ◽  
Author(s):  
Hana Bessler ◽  
Galila Agam ◽  
Meir Djaldetti
Keyword(s):  
Protein Synthesis ◽  
Fold Increase ◽  
Human Platelets ◽  
Polystyrene Latex ◽  
Latex Particles ◽  
The Third ◽  
Platelet Protein ◽  
Dose Dependent ◽  
Phagocytotic Activity

SummaryA three-fold increase of protein synthesis by human platelets during in vitro phagocytosis of polystyrene latex particles was detected. During the first two hours of incubation, the percentage of phagocytizing platelets and the number of latex particles per platelet increased; by the end of the third hour, the first parameter remained stable, while the number of latex particles per cell had decreased.Vincristine (20 μg/ml of cell suspension) inhibited platelet protein synthesis. This effect was both time- and dose-dependent. The drug also caused a decrease in the number of phagocytizing cells, as well as in their phagocytotic activity.

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