Biomaterial Database

Stereological studies on mesenteric resistance artery structure in New Zealand genetically hypertensive and control rats. 1993

J M Ledingham, and J A Millar

Department of Experimental Medicine, University of Otago Medical School, Dunedin, New Zealand.

1. Stereological methods were used to quantitate and compare the structure of mesenteric resistance arteries (MRA) in New Zealand genetically hypertensive (GH) rats aged 4, 10 and 16 weeks and their normotensive control strain (N). 2. Blood pressure (BP) (tail-cuff and intra-arterial) were recorded before the vessels were fixed by perfusion and embedded in Technovit Kulzer GmbH D-6393, Wehrheim, Germany). 3. Media and lumen volumes were measured on transverse sections (TS), by the Cavalieri method, and numbers of smooth muscle (SM) cells were estimated by the optical disector method. 4. There were no significant differences in lumen volume per unit vessel length between GH and age-matched N groups at any age. However, at 10 and 16 weeks volume in GH groups was 9-10% lower than their respective N groups. 5. Media volume per unit vessel length increased in GH rats at all ages. The media/lumen ratio also increased in GH at all ages. 6. Smooth muscle cell density (SM cell number per unit volume of media) decreased in GH rats at all ages, i.e. there was no evidence of hyperplasia. 7. Blood pressure (tail-cuff and intra-arterial) significantly increased in GH rats at 4 weeks of age and also at 10 and 16 weeks. 8. These results show that media volume is increased in GH early in life, is not due to hyperplasia, but may be due to hypertrophy of the SM cells, an increase in the amount of extracellular matrix or a combination of both.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D008638	Mesenteric Arteries	Arteries which arise from the abdominal aorta and distribute to most of the intestines.	Arteries, Mesenteric,Artery, Mesenteric,Mesenteric Artery
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D009520	New Zealand	A group of islands in the southwest Pacific. Its capital is Wellington. It was discovered by the Dutch explorer Abel Tasman in 1642 and circumnavigated by Cook in 1769. Colonized in 1840 by the New Zealand Company, it became a British crown colony in 1840 until 1907 when colonial status was terminated. New Zealand is a partly anglicized form of the original Dutch name Nieuw Zeeland, new sea land, possibly with reference to the Dutch province of Zeeland. (From Webster's New Geographical Dictionary, 1988, p842 & Room, Brewer's Dictionary of Names, 1992, p378)
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D002452	Cell Count	The number of CELLS of a specific kind, usually measured per unit volume or area of sample.	Cell Density,Cell Number,Cell Counts,Cell Densities,Cell Numbers,Count, Cell,Counts, Cell,Densities, Cell,Density, Cell,Number, Cell,Numbers, Cell
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014655	Vascular Resistance	The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.	Peripheral Resistance,Total Peripheral Resistance,Pulmonary Vascular Resistance,Systemic Vascular Resistance,Peripheral Resistance, Total,Resistance, Peripheral,Resistance, Pulmonary Vascular,Resistance, Systemic Vascular,Resistance, Total Peripheral,Resistance, Vascular,Vascular Resistance, Pulmonary,Vascular Resistance, Systemic
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus