THE EFFECT OF DIFFERENT DEGREES OF SUBDIAPHRAGMATIC AORTIC CONSTRICTION ON HEART WEIGHT AND BLOOD PRESSURE OF NORMAL AND HYPOPHYSECTOMIZED RATS

1955 ◽  
Vol 33 (1) ◽  
pp. 985-994 ◽  
Author(s):  
Margaret Beznák
Keyword(s):  
Blood Pressure ◽  
Cardiac Hypertrophy ◽  
Blood Pressure Response ◽  
Pressure Response ◽  
Heart Weight ◽  
Aortic Constriction ◽  
Hypophysectomized Rats ◽  
Intact Rats

The aortae of groups of normal and hypophysectomized rats were constricted with rings of five different sizes (0.93, 0.83, 0. 74, 0.71, and 0.63 mm. diameter). In normal rats constriction caused an increase in heart weight and blood pressure which was the greater the narrower the constriction. If constriction exceeded 0.74 mm., cardiac hypertrophy reached extremely high values, while the blood pressure was lower than in groups with less constriction. The blood pressure response to Adrenalin or Infundin increased in proportion to the degree of constriction down to 0.74 mm.; greater constriction reduced the response. In hypophysectomized rats no degree of aortic constriction produced hypertension or cardiac hypertrophy, yet the increase in blood pressure after Adrenalin or Infundin was as great as in the normal intact rats.

THE EFFECT OF DIFFERENT DEGREES OF SUBDIAPHRAGMATIC AORTIC CONSTRICTION ON HEART WEIGHT AND BLOOD PRESSURE OF NORMAL AND HYPOPHYSECTOMIZED RATS

1955 ◽  
Vol 33 (6) ◽  
pp. 985-994 ◽  
Author(s):  
Margaret Beznák
Keyword(s):  
Blood Pressure ◽  
Cardiac Hypertrophy ◽  
Blood Pressure Response ◽  
Pressure Response ◽  
Heart Weight ◽  
Aortic Constriction ◽  
Hypophysectomized Rats ◽  
Intact Rats

The aortae of groups of normal and hypophysectomized rats were constricted with rings of five different sizes (0.93, 0.83, 0. 74, 0.71, and 0.63 mm. diameter). In normal rats constriction caused an increase in heart weight and blood pressure which was the greater the narrower the constriction. If constriction exceeded 0.74 mm., cardiac hypertrophy reached extremely high values, while the blood pressure was lower than in groups with less constriction. The blood pressure response to Adrenalin or Infundin increased in proportion to the degree of constriction down to 0.74 mm.; greater constriction reduced the response. In hypophysectomized rats no degree of aortic constriction produced hypertension or cardiac hypertrophy, yet the increase in blood pressure after Adrenalin or Infundin was as great as in the normal intact rats.

Effect of Growth Hormone Preparations on Cardiac Hypertrophy and Blood Pressure of Hypophysectomized Rats

1956 ◽  
Vol 184 (3) ◽  
pp. 563-566 ◽  
Author(s):  
Margaret Beznák
Keyword(s):  
Blood Pressure ◽  
Growth Hormone ◽  
Cardiac Hypertrophy ◽  
Body Growth ◽  
Bovine Growth Hormone ◽  
Aortic Constriction ◽  
Hypophysectomized Rats ◽  
Crystalline Growth

Of three growth hormone preparations only one (PGH 163-208A, Armour) restored cardiac hypertrophy and hypertension on aortic constriction in hypophysectomized rats near to the level seen in normal rats. The same aortic constriction caused no increase in the weight of the heart and no hypertension in untreated hypophysectomized rats and in similar rats treated with a bovine growth hormone preparation (R 285-174, Armour) or crystalline growth hormone (Dr. Li, Berkeley). The different action of the three preparations was not connected with their effect on appetite and on body growth. ACTH, 5 mg/rat/day, caused adrenal hypertrophy in hypophysectomized rats without raising their blood pressure. The weight of the heart and particularly the blood pressure after aortic constriction were, however, greater in hypophysectomized rats treated with ACTH than in their nontreated controls.

THE ROLE OF GROWTH HORMONE AND THYROXINE IN NEPHROGENIC HYPERTENSION AND CARDIAC HYPERTROPHY IN HYPOPHYSECTOMIZED RATS

1967 ◽  
Vol 45 (6) ◽  
pp. 993-1000 ◽  
Author(s):  
Margaret Beznak
Keyword(s):  
Blood Pressure ◽  
Growth Hormone ◽  
Cardiac Hypertrophy ◽  
Male Rats ◽  
Unilateral Nephrectomy ◽  
Aortic Constriction ◽  
Salt Loading ◽  
Hypophysectomized Rats

There was no indication of slowly developing hypertension and cardiac hypertrophy in hypophysectomized rats upon treatment with desoxycorticosterone and salt loading following unilateral nephrectomy. This was the case in both younger (less than 100 g) and older (220–260 g) male rats. However, the weight of the heart and kidney, the blood pressure, and the rate and output of the heart of normal and hypophysectomized rats following unilateral nephrectomy and treatment with desoxycorticosterone and salt loading were not too different when the hypophysectomized rats were given growth hormone and thyroxine. This agrees with the earlier conclusion that thyroxine and growth hormone are required in hypophysectomized rats for the development of hypertension and any significant enlargement of the heart, whether from aortic constriction or from nephrogenic causes.

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