Biomaterial Database

Pulmonary capillary blood volume during lower body negative pressure: effect of gender. 1998

R W Gotshall, and L R Davrath

Department of Exercise and Sport Science, Colorado State University, Fort Collins 80523, USA.

BACKGROUND The purpose of this study was to examine the changes in pulmonary capillary blood volume (VC) in men and women during lower body negative pressure (LBNP). Additionally, the components of lung diffusion capacity were measured and evaluated for the effect of gender and LBNP. METHODS There were 6 men and 6 women who underwent a staged LBNP protocol to -40 mm Hg. The diffusion of the lung for carbon monoxide (DLCO) was determined at two levels of inspired oxygen (21% and 60%). DLCO was separated into the diffusion capacity of the membrane (DLM) and the diffusion capacity of blood. RESULTS During supine rest, DLCO values for men were larger than for women and were 39.8 +/- 3.8 and 32.2 +/- 2.2 ml.min-1.mm-1 Hg, respectfully. DLCO decreased equally with each stage of LBNP for men and women. VC during supine rest was greater for men (131 +/- 8 ml) than for women (92.7 +/- 7 ml). VC also declined with each stage of LBNP, and the decline was similar for men and women. DLM did not change with LBNP. CONCLUSIONS The decrease in DLCO with LBNP is due to the reductions in thoracic blood volume in both men and women. These thoracic blood volume changes do not explain the previously reported reduced tolerances to LBNP for women because the reductions in thoracic blood volume were similar for men and women.

UI	MeSH Term	Description	Entries
D008150	Lower Body Negative Pressure	External decompression applied to the lower body. It is used to study orthostatic intolerance and the effects of gravitation and acceleration, to produce simulated hemorrhage in physiologic research, to assess cardiovascular function, and to reduce abdominal stress during childbirth.	Abdominal Decompression,Decompression, Abdominal,LBNP
D008297	Male		Males
D010102	Oxygen Inhalation Therapy	Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)	Inhalation Therapy, Oxygen,Therapy, Oxygen Inhalation,Inhalation Therapies, Oxygen,Oxygen Inhalation Therapies,Therapies, Oxygen Inhalation
D011652	Pulmonary Circulation	The circulation of the BLOOD through the LUNGS.	Pulmonary Blood Flow,Respiratory Circulation,Circulation, Pulmonary,Circulation, Respiratory,Blood Flow, Pulmonary,Flow, Pulmonary Blood,Pulmonary Blood Flows
D011653	Pulmonary Diffusing Capacity	The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.	Capacity, Pulmonary Diffusing,Diffusing Capacity, Pulmonary
D001810	Blood Volume	Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.	Blood Volumes,Volume, Blood,Volumes, Blood
D002196	Capillaries	The minute vessels that connect arterioles and venules.	Capillary Beds,Sinusoidal Beds,Sinusoids,Bed, Sinusoidal,Beds, Sinusoidal,Capillary,Capillary Bed,Sinusoid,Sinusoidal Bed
D002248	Carbon Monoxide	Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)	Monoxide, Carbon
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man