Effects of estrogen and progesterone on carotid body neural output responsiveness to hypoxia

1990 ◽  
Vol 68 (5) ◽  
pp. 1909-1916 ◽  
Author(s):  
B. Hannhart ◽  
C. K. Pickett ◽  
L. G. Moore
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Carotid Body ◽  
Shape Parameter ◽  
Estrogen Treatment ◽  
Progesterone Treatment ◽  
Before And After ◽  
Progressive Hypoxia ◽  
End Tidal ◽  
Sites Of Action

Pregnancy increases ventilatory and carotid body neural output (CBNO) responsiveness to hypoxia in cats (J. Appl. Physiol. 67: 797-803, 1989). To determine whether progesterone and estrogen stimulated hypoxic ventilatory and CBNO responsiveness, we studied 24 castrated male cats before and after 1 wk of placebo, estrogen, progesterone, or estrogen plus progesterone treatment. Estrogen plus progesterone treatment decreased end-tidal PCO2 (-3.8 +/- 0.8 Torr) and increased hypoxic ventilatory responsiveness, whereas estrogen or progesterone alone had no effect. Animals receiving progesterone alone or in combination with estrogen had higher CBNO responsiveness than placebo or estrogen-treated animals (shape parameter A = 45 +/- 7 vs. 27 +/- 4, P less than 0.05). However, the group treated with estrogen plus progesterone did not have greater CBNO responsiveness to hypoxia than the group receiving progesterone alone. The cross plot of the simultaneously measured CBNO and ventilation during progressive hypoxia revealed a greater slope in the estrogen-treated than in the placebo animals, suggesting that estrogen treatment increased central nervous system transduction of CBNO into ventilation. Thus the data taken together suggested that progesterone and estrogen had a combination of peripheral (carotid body) and central sites of action such that the administration of both hormones together had a more consistent stimulatory effect on hypoxic ventilatory responsiveness than either hormone alone.

Role of endogenous female hormones in hypoxic chemosensitivity

1997 ◽  
Vol 83 (5) ◽  
pp. 1706-1710 ◽  
Author(s):  
Koichiro Tatsumi ◽  
Cheryl K. Pickett ◽  
Christopher R. Jacoby ◽  
John V. Weil ◽  
Lorna G. Moore
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Shape Parameter ◽  
Ovarian Hormones ◽  
Serum Progesterone ◽  
Ventilatory Responses ◽  
Female Hormones ◽  
Before And After ◽  
End Tidal

Tatsumi, Koichiro, Cheryl K. Pickett, Christopher R. Jacoby, John V. Weil, and Lorna G. Moore. Role of endogenous female hormones in hypoxic chemosensitivity. J. Appl. Physiol. 83(5): 1706–1710, 1997.—Effective alveolar ventilation and hypoxic ventilatory response (HVR) are higher in females than in males and after endogenous or exogenous elevation of progesterone and estrogen. The contribution of normal physiological levels of ovarian hormones to resting ventilation and ventilatory control and whether their site(s) of action is central and/or peripheral are unclear. Accordingly, we examined resting ventilation, HVR, and hypercapnic ventilatory responses (HCVR) before and 3 wk after ovariectomy in five female cats. We also compared carotid sinus nerve (CSN) and central nervous system translation responses to hypoxia in 6 ovariectomized and 24 intact female animals. Ovariectomy decreased serum progesterone but did not change resting ventilation, end-tidal[Formula: see text], or HCVR (all P = NS). Ovariectomy reduced the HVR shape parameter A in the awake (38.9 ± 5.5 and 21.2 ± 3.0 before and after ovariectomy, respectively, P < 0.05) and anesthetized conditions. The CSN response to hypoxia was lower in ovariectomized than in intact animals (shape parameter A = 22.6 ± 2.5 and 54.3 ± 3.5 in ovariectomized and intact animals, respectively, P < 0.05), but central nervous system translation of CSN activity into ventilation was similar in ovariectomized and intact animals. We concluded that ovariectomy decreased ventilatory and CSN responsiveness to hypoxia, suggesting that the presence of physiological levels of ovarian hormones influences hypoxic chemosensitivity by acting primarily at peripheral sites.

Hypoxic ventilatory sensitivity in men is not reduced by prolonged hyperoxia (Predictive Studies V and VI)

1998 ◽  
Vol 84 (1) ◽  
pp. 292-302 ◽  
Author(s):  
R. Gelfand ◽  
C. J. Lambertsen ◽  
J. M. Clark ◽  
E. Hopkin
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adverse Effects ◽  
Exposure Time ◽  
Carotid Body ◽  
Exposure Limits ◽  
Peripheral Chemoreceptors ◽  
Human Organ ◽  
Ventilatory Responses ◽  
Before And After

Gelfand, R., C. J. Lambertsen, J. M. Clark, and E. Hopkin.Hypoxic ventilatory sensitivity in men is not reduced by prolonged hyperoxia (Predictive Studies V and VI). J. Appl. Physiol. 84(1): 292–302, 1998.—Potential adverse effects on the O2-sensing function of the carotid body when its cells are exposed to toxic O2 pressures were assessed during investigations of human organ tolerance to prolonged continuous and intermittent hyperoxia (Predictive Studies V and VI). Isocapnic hypoxic ventilatory responses (HVR) were determined at 1.0 ATA before and after severe hyperoxic exposures: 1) continuous O2 breathing at 1.5, 2.0, and 2.5 ATA for 17.7, 9.0, and 5.7 h and 2) intermittent O2 breathing at 2.0 ATA (30 min O2-30 min normoxia) for 14.3 O2 h within 30-h total time. Postexposure curvature of HVR hyperbolas was not reduced compared with preexposure controls. The hyperbolas were temporarily elevated to higher ventilations than controls due to increments in respiratory frequency that were proportional to O2 exposure time, not O2 pressure. In humans, prolonged hyperoxia does not attenuate the hypoxia-sensing function of the peripheral chemoreceptors, even after exposures that approach limits of human pulmonary and central nervous system O2 tolerance. Current applications of hyperoxia in hyperbaric O2therapy and in subsea- and aerospace-related operations are guided by and are well within these exposure limits.

Effects of hypercapnia and hypoxia on inspiratory and expiratory diaphragmatic activity in conscious cats

1994 ◽  
Vol 77 (4) ◽  
pp. 1644-1652 ◽  
Author(s):  
M. Bonora ◽  
M. Boule
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Steady State ◽  
Electromyographic Activity ◽  
Large Reduction ◽  
Before And After ◽  
The Central Nervous System ◽  
State Changes ◽  
Chemical Stimuli ◽  
Adult Cats

The influence of steady-state changes in chemical stimuli on ventilation and electromyographic activity of the diaphragm during both inspiration (total DI) and expiration (total DE) was studied in unanesthetized intact adult cats before and after carotid denervation. In intact animals, during hypercapnia (2 4, and 6% CO2), tidal volume (VT) and total DI increase, whereas total DE did not consistently change. During ambient hypocapnic hypoxia (14, 12, and 10% O2), VT increased only at 10% O2, whereas total DI increased at all levels studied. Total DE increased substantially at 14% O2, persisting up to the end of expiration with 12 and 10% O2. This effect was markedly attenuated during normocapnic hypoxia. During CO hypoxemia (1,700 ppm in air), VT as well as total DI and total DE decreased because of a large reduction in inspiratory and expiratory time elicited by tachypneic breathing. The effects of hypercapnia and hypoxia persisted after carotid denervation. Therefore, 1) in contrast to hypercapnia, hypoxia markedly enhances the expiratory diaphragmatic activity, 1) this expiratory braking mechanism depends on the severity of hypoxia and is partly due to hypocapnia secondary to hypoxia; and 3) because this effect was observed after carotid denervation and during CO hypoxemia, it may arise in the central nervous system, possibly in bulbopontine structures.

Control Points To Reduce Movement of Central Nervous System Tissue during Beef Slaughter

2017 ◽  
Vol 80 (2) ◽  
pp. 355-360
Author(s):  
J. L. Aalhus ◽  
R. D. Thacker ◽  
I. L. Larsen ◽  
J. C. Roberts ◽  
M. A. Price ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cold Water ◽  
Effective Means ◽  
Hot Water ◽  
Spongiform Encephalopathy ◽  
Cross Contamination ◽  
Central Nervous System Tissue ◽  
Before And After ◽  
Disease Variant

ABSTRACT Consumption of central nervous system tissue (CNST) from cattle with bovine spongiform encephalopathy (BSE) is thought to cause the human neurological disease, variant Creutzfeldt-Jacob disease. To identify points of cross-contamination of beef carcasses with CNST, 55 young beef cattle were slaughtered and processed through a federally inspected multispecies abattoir. The objectives of this study were to evaluate CNST spread following the placement of a plug in the penetration site of the skull after captive bolt stunning, to evaluate cross-contamination of carcasses before and after splitting, to compare the effects of hot water pasteurization (84°C for 10 s) versus cold water wash (10°C for 30 s) for reducing CNST on the carcass, and to examine other possible sources of cross-contamination in the abattoir. Results indicated that the use of a plastic plug reduced CNST contamination near the bolt penetration site. This study also confirmed that carcass splitting resulted in an increase in CNST contamination at various areas of the carcass. Hot water pasteurization appeared to be an effective means of removing CNST contamination from carcasses in most of the areas sampled.

Risperidone in the Treatment of Pervasive Developmental Disorder

1994 ◽  
Vol 39 (7) ◽  
pp. 400-405 ◽  
Author(s):  
Scot E. Purdon ◽  
Wilson Lit ◽  
Alain Labelle ◽  
Barry D.W. Jones
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Pervasive Developmental Disorder ◽  
Autistic Disorder ◽  
Developmental Disorder ◽  
Psychiatric Patients ◽  
High Likelihood ◽  
Before And After ◽  
History Of ◽  
The Central Nervous System

Elevated concentrations of blood serotonin have been documented in autistic children and mentally retarded adults. Antiserotonergic pharmacotherapy has been partially effective in treating a subgroup of children with autistic disorder. Therefore, the possibility is raised that an antiserotonergic treatment may be of value to adult psychiatric patients with a history of pervasive developmental disorder. Two such cases are described where the patients underwent psychiatric and neuropsychological examination before and after treatment with risperidone, a potent 5-HT2 antagonist with additional D2 antagonistic properties. Particular improvements were documented in both patients, despite long histories of cognitive compromise and high likelihood of damage to the central nervous system.

Energy metabolism of dogs after total destruction of the central nervous system

1963 ◽  
Vol 204 (2) ◽  
pp. 330-336 ◽  
Author(s):  
Paulo Enéas Galvão ◽  
Jacob Tarasantchi ◽  
Carlos Alberto E. De Magalhães
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Respiratory Muscles ◽  
Nacl Solution ◽  
Muscle Tonus ◽  
Male Adult ◽  
Total Destruction ◽  
Before And After ◽  
The Central Nervous System ◽  
Metabolic Action

The central nervous system of male adult dogs was destroyed by an injection in the cisterna magna, of a 20% NaCl solution, under 60 cm Hg pressure, during 6 min (technique of Galvão and Pereira). One hundred and sixteen O2 consumption determinations were made by analysis of the expired air or of the air pumped through the lungs, in 28 dogs, before and after CNS destruction. The metabolism level was generally well maintained during the first hours after the destruction and was materially unaltered in some dogs until death. However, in many dogs the heat production decreased more or less gradually in the later hours, and attained a mean lowering of 16.8%. The anesthesia employed, the abolition of muscle tonus and work of respiratory muscles, the respiration of the CNS, and the loss of a trophic or metabolic action of the CNS are discussed in an attempt to explain the metabolic rate of animals deprived of CNS.

Effect of Nicotine on the Synapse of the Central Nervous System

1958 ◽  
Vol 192 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Sadayuki F. Takagi ◽  
Yutaka Oomura
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Synaptic Transmission ◽  
Reflex Activity ◽  
Synaptic Delay ◽  
Synaptic Potential ◽  
Before And After ◽  
The Central Nervous System ◽  
High Concentrations

The effect of nicotine on synaptic transmission in the frog and cat spinal cord was studied. Both a regular wick electrode and a microelectrode of the Ling-Gerard type were used. The reflex activity of the bullfrog spinal cord is facilitated by 0.01% nicotine solution, but is depressed and abolished by 0.1% solution. In the cat, intravenous administration of 150 mg/kg fails to block reflex activity, but topical application does block. The intracellular potential, of both frog and cat motoneurones, shows no change in the synaptic potential after application of the drug, but the spike appears after a shorter synaptic delay and one or more additional spikes appear. When the synaptic delay becomes sufficiently short, however, all spikes suddenly disappear, leaving the still unchanged synaptic potential. Occasionally the synaptic delay is again increased just before the spike potentials disappear. The excitability of a frog motoneurone was measured, by a recording microelectrode, before and after nicotine application. The drug first increased and then decreases excitability. Epinephrine can restore a reflex discharge depressed or abolished by nicotine. It is concluded that high concentrations of nicotine block synaptic transmission in the central nervous system, acting on the cell body but not on the synaptic potential.

scholarly journals Virulence profile of strains of Cryptococcus neoformans var. grubii evaluated by experimental infection in BALB/c mice and correlation with exoenzyme activity

2006 ◽  
Vol 55 (2) ◽  
pp. 139-142 ◽  
Author(s):  
Eriques Gonçalves da Silva ◽  
Francisco de Assis Baroni ◽  
Flavio César Viani ◽  
Luciana da Silva Ruiz ◽  
Rinaldo Ferreira Gandra ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cryptococcus Neoformans ◽  
Experimental Infection ◽  
The Other ◽  
Death Rates ◽  
Before And After ◽  
The Central Nervous System ◽  
Neurological Infection

To evaluate the virulence profile of strains of Cryptococcus neoformans var. grubii, 62 strains of this yeast were inoculated into BALB/c mice. It was found that 69 % of the strains were significantly more lethal to the mice and were recovered from a higher percentage (60 %) of the organs compared with the other 31 % of the strains, which were recovered from 35 % of organs tested. Those strains that provoked higher death rates were also recovered from the central nervous system at a higher rate (84 %) than the less lethal strains (32 %). This finding led to an investigation of the factors that enhanced the capacity for neurological infection and death of the animals. The results of this study suggested that environmental strains present different degrees of virulence. The correlation of exoenzyme production before and after inoculation and between the groups of mice indicated that exoenzyme production had no influence on differences in virulence among the strains studied.

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