Effects of Hypertension and Its Reversal on Aortic Metabolism in the Rat

The relationship between aortic metabolism and hypertension was examined in spontaneously hypertensive rats (SHR) and in the normotensive Wistar-Kyoto (WKY) strain of rats. Comparative studies between age-matched animals of both strains showed in the SHR, enhanced activities of the aortic enzymes, iV-acetyl β-glucosaminidase (NAGA) and acid phosphatase, which are associated with lysosomes. Similar increases were shown for aortic 5-nucleotidase activity. Antihypertensive drug treatment of 30-week-old SHR for 17 weeks effectively lowered blood pressure and reduced the activity of aortic NAGA and acid phosphatase in the SHR to control levels. 5′-Nucleotidase activity remained significantly elevated, and aortic collagen and elastin concentrations were unaffected by antihypertensive drug treatment. Hypertension was produced in WKY rats by deoxycorticosterone treatment for either 4 or 7 weeks and then was reversed by discontinuing treatment and maintaining the pretreated animals on a low-salt diet for up to 11 weeks. At the end of the treatment period, aortic enzymatic activity was increased significantly, as were heart and aortic weights. Following the reversal of hypertension, the activity of the lysosomal enzymes was decreased significantly, but 5-nucleotidase activity remained elevated. Collagen and elastin concentrations were not affected by mineralocorticoid treatment, but the total amount of connective tissue protein was increased and remained elevated following the reversal of hypertension, paralleling the changes in aortic weight. The studies indicate that etiologically different forms of hypertension result in characteristic changes in aortic metabolism which are not completely reversed by subsequent blood pressure reduction.

[1]  S. Schwartz,et al.  Aortic endothelial cell replication. I. Effects of age and hypertension in the rat. , 1977, Circulation research.

[2]  A. Chobanian,et al.  Effect of atherosclerosis on lysosomal cholesterol esterase activity in rabbit aorta. , 1977, Journal of lipid research.

[3]  D. Urbanová,et al.  VESSEL WALL METABOLISM IN SHR RATS IN RELATION TO ATHEROSCLEROSIS , 1976, Annals of the New York Academy of Sciences.

[4]  E. Daniel,et al.  Calcium Accumulation and Enzymatic Activities of Subcellular Fractions from Aortas and Ventricles of Genetically Hypertensive Rats , 1976, Circulation research.

[5]  E. Landon,et al.  Energy-dependent calcium uptake activity of microsomes from the aorta of normal and hypertensive rats. , 1975, Biochimica et biophysica acta.

[6]  J. Lowenstein,et al.  5'-Nucleotidase from smooth muscle of small intestine and from brain. Inhibition of nucleotides. , 1975, Biochemistry.

[7]  M. Amer,et al.  Aberrations of cyclic nucleotide metabolism in the hearts and vessels of hypertensive rats. , 1974, Proceedings of the National Academy of Sciences of the United States of America.

[8]  A. Ooshima,et al.  Increased collagen synthesis in blood vessels of hypertensive rats and its reversal by antihypertensive agents. , 1974, Proceedings of the National Academy of Sciences of the United States of America.

[9]  R. Riley,et al.  Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs , 1974, Circulation research.

[10]  S. Spector,et al.  Hypertension, antihypertensive drugs and norepinephrine in blood vessels , 1974 .

[11]  C. Duve,et al.  Lysosomes of the arterial wall: II. Subcellular fractionation of aortic cells from rabbits with Experimental Atheroma , 1974 .

[12]  H. Wolinsky,et al.  Modification of the Effects of Hypertension on Lysosomes and Connective Tissue in the Rat Aorta , 1974, Circulation research.

[13]  J. Giese.  Renin, angiotensin and hypertensive vascular damage: a review. , 1973, The American journal of medicine.

[14]  A. Ooshima.  Enzymological studies on arteries in spontaneously hypertensive rats. , 1973, Japanese circulation journal.

[15]  R. Ross,et al.  Atherosclerosis and the Arterial Smooth Muscle Cell , 1973 .

[16]  H. Wolinsky.  Mesenchymal Response of the Blood Vessel Wall: A Potential avenue for understanding and treating Atherosclerosis , 1973, Circulation research.

[17]  T. Peters,et al.  LYSOSOMES OF THE ARTERIAL WALL , 1972, The Journal of experimental medicine.

[18]  H. Wolinsky,et al.  Effects of Hypertension and Its Reversal on the Thoracic Aorta of Male and Female Rats: Morphological and Chemical Studies , 1971, Circulation research.

[19]  C. Dollery,et al.  Prognosis of treated hypertension. Changes in life expectancy and causes of death between 1952 and 1967. , 1970, The Quarterly journal of medicine.

[20]  J. R. Beck,et al.  Adrenergic receptors in human veins. , 1970, Canadian Medical Association journal.

[21]  R. Berne,et al.  Release of adenosine by the normal myocardium in dogs and its relationship to the regulation of coronary resistance. , 1969, Circulation research.

[22]  J. Shepherd,et al.  Beta-receptor mechanisms in the superficial limb veins of the dog. , 1969, The Journal of clinical investigation.

[23]  D. Spiro,et al.  The cellular pathology of experimental hypertension. IV. Evidence for increased vascular permeability. , 1969, The American journal of pathology.

[24]  G. Johnsson,et al.  Comparative effects of isoprenaline and nitroglycerin on consecutive vascular sections in the skeletal muscle of the cat. , 1968, Angiologica.

[25]  D. Kramsch,et al.  Arterial wall metabolism in experimental hypertension of coarctation of the aorta of short duration. , 1968, The Journal of clinical investigation.

[26]  T. Zsotér,et al.  Adrenoceptive sites in the veins. , 1967, British journal of pharmacology and chemotherapy.

[27]  P. Vanhoutte,et al.  Effects of monoamines on the capacity of isolated veins. , 1967, Archives internationales de pharmacodynamie et de therapie.

[28]  F. Abboud,et al.  VENOUS AND ARTERIAL RESPONSES TO STIMULATION OF BETA ADRENERGIC RECEPTORS. , 1965, The American journal of physiology.

[29]  E. J. Miller,et al.  The utilization of lysine in the biosynthesis of elastin crosslinks. , 1964, Biochemical and biophysical research communications.

[30]  K. Burton.  A study of the conditions and mechanism of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acid. , 1956, The Biochemical journal.

[31]  H. Dale,et al.  The control of circulation through the liver , 1932, The Journal of physiology.

[32]  S. Udenfriend,et al.  Reduction of blood pressure and vascular collagen in hypertensive rats by beta-aminopropionitrile. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[33]  H. Wolinksy.  Role of lysosomes in vascular disease: a unifying theme. , 1976, Annals of the New York Academy of Sciences.

[34]  E. Freis.  Modification of Hypertension by Antihypertensive Drug Treatment in Spontaneously Hypertensive Rats , 1972 .

[35]  A. Ooshima,et al.  Dietary Effects on Cardiovascular Lesions in Spontaneously Hypertensive Rats , 1972 .

[36]  A. Grollman.  The Spontaneous Hypertensive Rat: An Experimental Analogue of Essential Hypertension in the Human Being , 1972 .

[37]  K. Okamoto.  Spontaneous hypertension; its pathogenesis and complications , 1972 .

[38]  P. Vignais,et al.  Enzymic characterization and lipid composition of rat liver subcellular membranes. , 1971, Biochimica et biophysica acta.

[39]  T. Emerson,et al.  Effects of prostaglandin E1 and F2 alpha on venous return and other parameters in the dog. , 1971, The American journal of physiology.

[40]  A. Breckenridge.  Prognosis of treated hypertension , 1971, British heart journal.

[41]  Effects of treatment on morbidity in hypertension. II. Results in patients with diastolic blood pressure averaging 90 through 114 mm Hg. , 1970, JAMA.

[42]  W. Osswald,et al.  Adrenergic receptors in the veins of the dog. , 1969, European journal of pharmacology.

[43]  T. Emerson.  Changes of venous return and other hemodynamic parameters during bradykinin infusion. , 1967, The American journal of physiology.

[44]  R. Ballentine.  [145] Determination of total nitrogen and ammonia , 1957 .

[45]  E. King,et al.  The colorimetric determination of phosphorus. , 1932, The Biochemical journal.