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Blocking Of Acquisition But Not Expression Of Conditioned Fear-Potentiated Startle By Nmda Antagonists In The Amygdala, Mindy Miserendino, Catherine B. Sananes, Kathleen R. Melia, Michael Davis

Psychology Faculty Publications

Assessed the role of N-methyl-{d}-aspartate (NMDA) receptors in the amygdala in associative fear conditioning. 132 rats were implanted with cannulae aimed at the basolateral amygdaloid nuclei, while 13 controls had cannulae aimed at the interpositus nuclei of the cerebellum. NMDA antagonists infused into the amygdala blocked the acquisition, but not the expression, of fear conditioning measured with a behavioral assay mediated by a defined neural circuit (fear-potentiation of the acoustic startle reflex). This effect showed anatomical and pharmacological specificity, and was not attributable to reduced salience of the stimuli of light or shock used in training. An NMDA-dependent process in …

Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green

Dartmouth Scholarship

It was previously shown that spleen cells from endogenous ecotropic murine leukemia virus emv-14+ AKXL-5 mice fail to stimulate an anti-AKR/Gross virus cytolytic T-lymphocyte (CTL) response in a mixed lymphocyte culture with primed C57BL/6 responder spleen cells, whereas spleen cells from AKXL strains carrying the very similar emv-11 provirus do stimulate a response (Green and Graziano, Immunogenetics 23:106-110, 1986). We wished to determine whether the lack of response with AKXL-5 spleen cells was at the level of recognition between effector cell and target cell and whether the relevant mutation was within the emv-14 provirus. It is shown here that EMV-negative …

Effects Of Ketoconazole On Uterine Weight And On Unbound Serum Estradiol Relative To Vaginal Cornification In Rats, Leonard L. Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ketoconazole is a broad-spectrum antifungal with oral activity and is documented to block steroid biosynthesis in fungi and mammals.

Estradiol-primed ovariectomized rats lose the estradiol-induced, cornified layer of the vaginal epithelium as a result of ketoconazole treatment. This effect is not explained by current knowledge of ketoconazole's mechanism of action.

Ketoconazole's effect on estradiol's binding to either receptors in target tissues (target-cell receptors) or serum-estradiol-carrying proteins in the aforementioned rats was investigated.

The uterus is responsive to estradiol treatment, which causes an increase in uterine size and weight. This tissue is a sensitive means of studying the effects of ketoconazole …

Plasma Native And Peptidase-Derivable Met-Enkephalin Responses To Restraint Stress In Rats. Adaptation To Repeated Restraint, K. Pierzchala, G. R. Van Loon

Internal Medicine Faculty Publications

Met-enkephalin and related proenkephalin A-derived peptides circulate in plasma at picomolar concentration as free, native pentapeptide and at nanomolar concentration in cryptic forms. We have optimized conditions for measurement of immunoreactive Met-enkephalin in plasma and for generation by trypsin and carboxypeptidase B of much greater amounts of total peptidase-derivable Met-enkephalin in plasma of rats, dogs, and humans. Free Met-enkephalin (11 pM) is constituted by native pentapeptide and its sulfoxide. Characterization of plasma total Met-enkephalin derived by peptidic hydrolysis revealed a small amount (38 pM) of Met-enkephalin associated with peptides of molecular mass less than 30,000 D, and probably derived from …

Susceptibility Of Hepatic Microcirculation To Reperfusion Injury: A Comparison Of Adult And Suckling Rats., Alan M. Yahanda Md, Facs, C N Paidas, M G Clemens

Other Specialties

Primary graft failure and vascular thromboses are frequent complications of liver transplantation, yet the mechanisms responsible remain unclear. Previous work from our laboratory has shown that hepatic reperfusion injury results in damage at the microvessel level. The present study was performed to determine whether an increased susceptibility of immature animals to microvascular injury during reperfusion might be a contributing factor in these complications. Suckling (35 to 50 g) or adult (250 to 400 g) rats were subjected to 30 or 60 minutes of hepatic ischemia to the left and median lobes followed by 90 minutes of reperfusion. Control animals were …

Regulation Of Fatty Acid Biosynthesis By Physical Exercise Mechanisms Of Inhibition, Rita Priyadarshani Francis

Master's Theses

In partially purified cell-free extracts of rat liver, nonexhaustive, daily exercise results in a 40 to 90% inhibition of FAB by decreasing the catalytic activity of acetyl coenzyme A carboxylase (ACC), the rate-limiting enzyme in the de novo FAB pathway in vitro. ACC inhibitory mechanisms are postulated to include: phosphorylation of ACC and production of a noncompetitive inhibitory substance.

Data obtained after purification of rat liver ACC to homogeneity suggest that decreased ACC activity in exercised rats cannot be attributed to the well-documented control of ACC by reversible phosphorylation, but are more likely due to the presence of a noncompetitive …