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Ventilatory Response To Carbon Dioxide Stimuli In Aged Humans, Marc Jean Poulin
Ventilatory Response To Carbon Dioxide Stimuli In Aged Humans, Marc Jean Poulin
Digitized Theses
This thesis examined age-related changes in the ventilatory response to exercise and in the ventilatory response to inhaled carbon dioxide (CO{dollar}\sb2{dollar}) at rest. Specifically, the purposes were to: (1) examine the ventilatory response to CO{dollar}\sb2{dollar} production (VCO{dollar}\sb2{dollar}) during graded exercise below the ventilation threshold (T{dollar}\sb{lcub}\rm \.VE{rcub}{dollar}) in men and women aged 55 to 86 yrs, (2) determine the ventilatory response to CO{dollar}\sb2{dollar} at rest and evaluate the CO{dollar}\sb2{dollar} sensitivity of the central and peripheral chemoreceptors in young (YS, n = 7, 28.3 yrs) and old (OS, n = 11, 76.1 yrs) humans, and (3) determine the temporal parameters of the …
Cyclic Adenosine 3',5'-Monophosphate And Prostaglandin E(2) During Decidualization In The Rat, Gayle M. Yee
Cyclic Adenosine 3',5'-Monophosphate And Prostaglandin E(2) During Decidualization In The Rat, Gayle M. Yee
Digitized Theses
Prostaglandin E{dollar}\sb2{dollar} (PGE{dollar}\sb2{dollar}) is an important mediator of implantation and decidualization during pregnancy. However, its mechanism of action in the uterus is unclear. Endometrial alkaline phosphatase (ALP) activity increases during decidualization in many species and provides a marker for assessment of cellular aspects of decidualization. The objective of this study was to examine the relationship between PGE{dollar}\sb2{dollar} and cyclic adenosine 3{dollar}\sp\prime{dollar},5{dollar}\sp\prime{dollar}-monophosphate (cAMP) during decidualization in the rat. In ovariectomized rats treated with estrogen and progesterone to sensitize the uteri for decidualization, intrauterine infusion of indomethacin, an inhibitor of endogenous PG synthesis, inhibited the increase in endometrial ALP activity, which occurred …
Control Of Tonic Sympathetic Nerve Activity By The Brainstem In Rats, Kristen Hayes
Control Of Tonic Sympathetic Nerve Activity By The Brainstem In Rats, Kristen Hayes
Digitized Theses
Control of tonic firing of sympathetic nerves by the rostral ventrolateral medulla (RVLM) and the pontine reticular formation (PRF) was investigated. Electrical activity of renal, splenic, mesenteric and preganglionic greater splanchnic nerves and T{dollar}\sb{lcub}13{rcub}{dollar} white rami was recorded in artificially respired, urethane-anaesthetized rats. Glycine (1.0M;180nl) was microinjected into the RVLM to inhibit neuronal discharge and effects on these nerves were compared. To study descending inhibitory influences on these nerves, effects of RVLM blockade were compared to effects of cervical spinal cord transection. RVLM blockade caused greater decreases in discharge of renal ({dollar}-44\ \pm\ 3\%{dollar}) than splenic ({dollar}-31\ \pm\ 2\%{dollar}) nerves, …
Regulation Of Choline Acetyltransferase In Rat Hippocampal Synaptosomes, Bonnie Marie Schmidt
Regulation Of Choline Acetyltransferase In Rat Hippocampal Synaptosomes, Bonnie Marie Schmidt
Digitized Theses
Choline acetyltransferase (ChAT; EC 2.3.1.6) catalyses the biosynthesis of acetylcholine (ACh) from choline and acetylCoenzyme A in cholinergic neurons. Within nerve terminals, this enzyme exists in both cytosolic and membrane-bound forms, although the role of the latter fraction is not clear. ChAT is clearly subject to long-term regulation (over periods of hours to days), likely through alterations in protein synthesis, however very little is known about short-term regulation (seconds to minutes). Therefore, the goals of this study were to determine the mechanisms of short-term regulation of ChAT activity and to elucidate the physiological role of membrane-bound ChAT in ACh biosynthesis.;Using …
Age-Related Changes In The Numbers And Physiological Properties Of Human Motor Units, Timothy John Doherty
Age-Related Changes In The Numbers And Physiological Properties Of Human Motor Units, Timothy John Doherty
Digitized Theses
Age-related changes in the numbers and physiological properties of human motor units (MUs) were examined in four studies.;In the first study, spike-triggered averaging was used to estimate the numbers of MUs in the biceps brachii and brachialis muscles. The maximum isometric twitch contraction (MTC) and maximum voluntary contraction (MVC) of the elbow flexors were also measured. In older subjects, the estimated numbers of MUs were significantly reduced (47%) whereas, average surface-detected motor unit action potential (S-MUAP) sizes were significantly larger (23%). Significant but less marked age-associated reductions were found for the MTC (33%) and MVC (33%).;In the second study Multiple …
Hsp 72 In Rat Skeletal Muscle: Fibre Type Differences And Effect Of Exercise, Marius Locke
Hsp 72 In Rat Skeletal Muscle: Fibre Type Differences And Effect Of Exercise, Marius Locke
Digitized Theses
Western blot analyses of SDS-PAGE separated proteins from various hindlimb muscles from non-exercised control animals probed with an HSP 72 monoclonal antibody, demonstrated the constitutive expression of HSP 72 in rat muscles comprised primarily of Type I muscle fibres (soleus), but not in muscles comprised primarily of Type IIB/X fibres (white gastrocnemius-WG). In muscles of mixed fibre type, (plantaris and red gastrocnemius-RG) HSP 72 content was proportional to the percentage of Type I fibres.;Immunolocalization of HSP 72 in cross-sections from the soleus muscle demonstrated that both Type I and Type IIA fibres expressed HSP 72, but Type I fibres expressed …