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.

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.

ANALYSIS OF THE BIPHASIC ACTION OF GROWTH HORMONE IN VITRO ON THE RAT DIAPHRAGM

1968 ◽  
Vol 57 (3_Suppl) ◽  
pp. S19-S35 ◽  
Author(s):  
Å. Hjalmarson
Keyword(s):  
Growth Hormone ◽  
Actinomycin D ◽  
Accumulation Rate ◽  
Inhibitory Effect ◽  
Bovine Growth Hormone ◽  
Rat Diaphragm ◽  
Dual Nature ◽  
Hypophysectomized Rats ◽  
D 20

ABSTRACT In vitro addition of bovine growth hormone (GH) to intact hemidiaphragms from hypophysectomized rats has previously been found to produce both an early stimulatory effect lasting for 2—3 hours and a subsequent late inhibitory effect during which the muscle is insensitive to further addition of GH (Hjalmarson 1968). These effects on the accumulation rate of α-aminoisobutyric acid (AIB) and D-xylose have been further studied. In presence of actinomycin D (20 μg/ml) or puromycin (100 μg/ml) the duration of the stimulatory effect of GH (25 μg/ml) was prolonged to last for at least 4—5 hours and the late inhibitory effect was prevented. Similar results were obtained when glucose-free incubation medium was used. Preincubation of the diaphragm at different glucose concentrations (0—5 mg/ml) for 3 hours did not change the GH sensitivity. Addition of insulin at start of incubation could not prevent GH from inducing its late inhibitory effect, while dexamethasone seemed to potentiate this effect of GH. Furthermore, adrenaline was found to decrease the uptake of AIB-14C and D-xylose-14C in the diaphragm, but not to change the sensitivity of the muscle to GH. Preincubation of the diaphragm for 3 hours with puromycin in a concentration of 200 μg/ml markedly decreased the subsequent basal uptake of both AIB-14C and D-xylose-14C, in the presence of puromycin, and abolished the stimulatory effect of GH on the accumulation of AIB-14C. However, the effect of GH on the accumulation of D-xylose-14C was unchanged. The present observations are discussed and evaluated in relation to various mechanisms of GH action proposed to explain the dual nature of the hormone.

Quercetin-Supplemented Diets Lower Blood Pressure and Attenuate Cardiac Hypertrophy in Rats With Aortic Constriction

2006 ◽  
Vol 47 (4) ◽  
pp. 531-541 ◽  
Author(s):  
Thunder Jalili ◽  
Justin Carlstrom ◽  
Sun Kim ◽  
David Freeman ◽  
Huifeng Jin ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Hypertrophy ◽  
Lower Blood Pressure ◽  
Aortic Constriction ◽  
Lower Blood

scholarly journals Growth hormone-releasing hormone attenuates cardiac hypertrophy and improves heart function in pressure overload-induced heart failure

2017 ◽  
Vol 114 (45) ◽  
pp. 12033-12038 ◽  
Author(s):  
Iacopo Gesmundo ◽  
Michele Miragoli ◽  
Pierluigi Carullo ◽  
Letizia Trovato ◽  
Veronica Larcher ◽  
...  
Keyword(s):  
Heart Failure ◽  
Growth Hormone ◽  
Cardiac Hypertrophy ◽  
Cardiac Function ◽  
Therapeutic Potential ◽  
Growth Hormone Releasing Hormone ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction

It has been shown that growth hormone-releasing hormone (GHRH) reduces cardiomyocyte (CM) apoptosis, prevents ischemia/reperfusion injury, and improves cardiac function in ischemic rat hearts. However, it is still not known whether GHRH would be beneficial for life-threatening pathological conditions, like cardiac hypertrophy and heart failure (HF). Thus, we tested the myocardial therapeutic potential of GHRH stimulation in vitro and in vivo, using GHRH or its agonistic analog MR-409. We show that in vitro, GHRH(1-44)NH2 attenuates phenylephrine-induced hypertrophy in H9c2 cardiac cells, adult rat ventricular myocytes, and human induced pluripotent stem cell-derived CMs, decreasing expression of hypertrophic genes and regulating hypertrophic pathways. Underlying mechanisms included blockade of Gq signaling and its downstream components phospholipase Cβ, protein kinase Cε, calcineurin, and phospholamban. The receptor-dependent effects of GHRH also involved activation of Gαs and cAMP/PKA, and inhibition of increase in exchange protein directly activated by cAMP1 (Epac1). In vivo, MR-409 mitigated cardiac hypertrophy in mice subjected to transverse aortic constriction and improved cardiac function. Moreover, CMs isolated from transverse aortic constriction mice treated with MR-409 showed improved contractility and reversal of sarcolemmal structure. Overall, these results identify GHRH as an antihypertrophic regulator, underlying its therapeutic potential for HF, and suggest possible beneficial use of its analogs for treatment of pathological cardiac hypertrophy.

Hypertension and Cardiac Hypertrophy in Growth Hormone-Deficient Rats

1994 ◽  
Vol 87 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Stephen B. Harrap ◽  
Shari R. Datodi ◽  
Emma K. Crapper ◽  
Leon A. Bach
Keyword(s):  
Blood Pressure ◽  
Growth Hormone ◽  
Body Weight ◽  
Cardiac Hypertrophy ◽  
Weight Ratio ◽  
The Body ◽  
Hormone Deficiency ◽  
Heart Weight ◽  
Deoxycorticosterone Acetate ◽  
F344 Rats

1. Growth hormone may influence cardiac growth during post-natal maturation or in response to hypertension, and the growth-hormone deficient dwarf rat model offers an opportunity to study this question. 2. We compared the blood pressure and heart weight of dwarf rats and Fischer (F344) control rats in early adulthood, after two hypertensive stimuli: unilateral renal ischaemia (two-kidney, one-clip) or the administration of deoxycorticosterone acetate and saline drinking fluid. 3. In untreated animals at 13 weeks of age the body weight of dwarf rats was significantly less than that of F344 rats, but the mean arterial pressure was similar. Although the hearts of dwarf rats were smaller than those of F344 rats, the heart weight/body weight ratio was significantly greater in dwarf rats. 4. Both dwarf and F344 rats developed similar hypertensive mean arterial pressures 5 weeks after left renal artery clipping or treatment with deoxycorticosterone acetate salt. The heart weights of hypertensive dwarf and F344 rats were equivalent, indicating a proportionally greater increase in cardiac size in dwarf rats for the same rise in blood pressure. 5. The plasma insulin-like growth factor-I level was markedly lower in dwarf than in F344 rats, and hypertension did not have any significant effects on these levels. 6. These findings indicate that the developmental increase in blood pressure and heart size in growing animals and the adaptive cardiac hypertrophy accompanying hypertension are not affected by growth hormone deficiency.

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