Biomaterial Database

Ventilatory response to hypoxia in rats: gender differences. 1996

J P Mortola, and C Saiki

Department of Physiology, McGill University, Montreal, Que., Canada.

The ventilatory response to hypoxia of adult conscious rats, measured during sleep as change in ventilation-oxygen consumption ratio (VE/VO2) while breathing 10% O2 for 15-30 min, was found to be approximately 23% larger in females (female) than in males (male, p < 0.001). Also arterial PCO2 during hypoxia decreased more in female. The gender difference occurred at all metabolic levels, and was not related to normoxic VE/VO2 or the hypometabolic response to hypoxia; it was solely due to greater hyperpnea in female. With hypoxia, changes in blood pressure, heart rate and body temperature were similar between male and female; hence, gender differences in baro- or thermal-stimuli were not a contributing factor. Hematocrit, hemoglobin, lung, heart and diaphragm mass/body weight were also similar, whereas respiratory system compliance was higher, and resistance lower, in female. Ovariectomy did not change the female response. In prepubertal rats the VE/VO2 hypoxic response was also larger in female (approximately 12%, p < 0.05). After prolonged (approximately 4 months) hypoxia, the gender difference in the response to acute hypoxia was no longer statistically significant. In conclusion, conscious adult female rats have a higher ventilatory response to hypoxia than male. The reason for the difference remains elusive, but is probably not due to ovarian hormones.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009929	Organ Size	The measurement of an organ in volume, mass, or heaviness.	Organ Volume,Organ Weight,Size, Organ,Weight, Organ
D010052	Ovariectomy	The surgical removal of one or both ovaries.	Castration, Female,Oophorectomy,Bilateral Ovariectomy,Bilateral Ovariectomies,Castrations, Female,Female Castration,Female Castrations,Oophorectomies,Ovariectomies,Ovariectomies, Bilateral,Ovariectomy, Bilateral
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D001831	Body Temperature	The measure of the level of heat of a human or animal.	Organ Temperature,Body Temperatures,Organ Temperatures,Temperature, Body,Temperature, Organ,Temperatures, Body,Temperatures, Organ
D002908	Chronic Disease	Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care (Dictionary of Health Services Management, 2d ed). For epidemiological studies chronic disease often includes HEART DISEASES; STROKE; CANCER; and diabetes (DIABETES MELLITUS, TYPE 2).	Chronic Condition,Chronic Illness,Chronically Ill,Chronic Conditions,Chronic Diseases,Chronic Illnesses,Condition, Chronic,Disease, Chronic,Illness, Chronic
D005260	Female		Females
D006400	Hematocrit	The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.	Erythrocyte Volume, Packed,Packed Red-Cell Volume,Erythrocyte Volumes, Packed,Hematocrits,Packed Erythrocyte Volume,Packed Erythrocyte Volumes,Packed Red Cell Volume,Packed Red-Cell Volumes,Red-Cell Volume, Packed,Red-Cell Volumes, Packed,Volume, Packed Erythrocyte,Volume, Packed Red-Cell,Volumes, Packed Erythrocyte,Volumes, Packed Red-Cell
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic