Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of marijuana smoke on maternal respiratory rate and gas exchange were examined in nine chronically instrumented, late gestation ewes carrying singletons. The magnitude of exposure was randomly varied producing peak plasma levels of delta-9-tetrahydrocannabinol (delta-9-THC) ranging from 0 to 161 ng/ml. delta-9-THC levels, respiratory rate and arterial blood gas tensions were monitored before and for two hours after inhalational exposure. When compared to placebo, marijuana smoke produced a dose dependent and sustained decrease in maternal respiratory rate and arterial oxygen tension without evidence of either systemic acidosis or carbon dioxide retention. A logarithmic relationship was observed between the blood level of delta-9-THC and the change in respiratory rate. The change plateaued at 30% of control at levels above 80 ng/ml. However, the relationship between the blood level of delta-9-THC and the change in arterial oxygen tension had a linear fit with a maximum decrease of 45% at a blood level of 160 ng/ml. No change was detected in minute ventilation. Fetal oxygen tension fell significantly and remained depressed after maternal values had returned to control levels. We conclude that, in this species, inhalational exposure to marijuana smoke induces a prolonged maternal ventilation/perfusion imbalance and limits fetal oxygen availability by one or more mechanisms.
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PMID:The effects of marijuana smoke on gas exchange in ovine pregnancy. 302 63

The effects of pulmonary artery infusion of delta-9-tetrahydrocannabinol (delta 9-THC), 0.5 mg/kg, have been studied in four pregnant sheep. Cardiac output (CO) decreased from a baseline of 4.49 +/- 0.91 l/min (mean +/- s.e.m.) to 4.19 +/- 0.87 at 3 min, 3.69 +/- 0.76 at 5 min, and 3.35 +/- 0.77 at 15 min post infusion and returned to baseline by 1 h post infusion. Maternal blood pressure (MBP) decreased from 114 +/- 9 to a nadir of 69 +/- 8 mmHg at 15 min post infusion. Uterine artery blood flow (UTABF) increased from 256 +/- 88 to 317 +/- 132 ml/min at 3 min post infusion, but this was not statistically significant. Maternal acidosis, hypercapnia, and hypoxemia also developed during the first 15 min post infusion. Although fetal blood pressure (FBP) decreased throughout the 1st h post infusion, statistically significant changes in FBP or fetal heart rate (FHR) were not observed. Umbilical artery blood flow (UMABF) increased from 188 +/- 58 to 211 +/- 68 1/min at 5 min post infusion and declined thereafter. This change was also statistically significant. As in the ewe the fetus developed acidosis and hypoxemia, but hypercapnia, although present, was not statistically significant. A single animal was studied following i.v. infusion of delta 9-THC (1 mg/kg). More pronounced effects, including a decrease in UTABF and UMABF, were noted. The sheep were maintained under pentobarbital anesthesia for the duration of the study.
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PMID:Acute cardiovascular effects of delta-9-tetrahydrocannabinol in pregnant anesthetized sheep. 632 73