EFFECT OF HYPOPHYSECTOMY AND HORMONE TREATMENT ON THE HEART–LUNG PREPARATION OF RATS

1966 ◽  
Vol 44 (1) ◽  
pp. 13-20 ◽  
Author(s):  
B. Korecky ◽  
M. Beznak ◽  
M. Korecka
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Left Ventricle ◽  
Hormone Treatment ◽  
The Other ◽  
Hypophysectomized Rats ◽  
Lung Preparation ◽  
Made In

Heart–lung preparations (h.l.p.) were made in normal rats, hypophysectomized rats, and in hypophysectomized rats treated with either growth hormone or thyroxine or both. While mean arterial pressure was kept constant at 100 mm Hg, the flow into the heart was increased stepwise until cardiac output did not rise any further (maximum cardiac output (m.c.o.)). Hypophysectomy substantially decreased the m.c.o., even when expressed per kilogram body weight. Thyroxine treatment alone or with growth hormone completely restored the m.c.o. to normal. However, when the m.c.o. was calculated per gram of left ventricle weight, it did not reach the normal level in any of the hypophysectomized rats investigated. Growth hormone, on the other hand, raised the stroke volume (expressed per gram of left ventricle) of hypophysectomized rats without affecting the rate of the heart.

CARDIAC PERFORMANCE IN HEART–LUNG PREPARATIONS OF RATS WITH EXPERIMENTAL CARDIAC HYPERTROPHY

1966 ◽  
Vol 44 (1) ◽  
pp. 21-27 ◽  
Author(s):  
B. Korecky ◽  
M. Beznak ◽  
M. Korecka
Keyword(s):  
Cardiac Output ◽  
Left Ventricle ◽  
Arterial Pressure ◽  
Cardiac Hypertrophy ◽  
Cardiac Performance ◽  
Aortic Constriction ◽  
Chronic Anemia ◽  
Stepwise Increase ◽  
Thyroxine Treatment ◽  
Made In

Heart-lung preparations (h.l.p.) were made in normal rats and in rats with cardiac hypertrophy produced by aortic constriction, thyroxine treatment, or chronic anemia. In the h.l.p., arterial pressure was kept constant at 100 mm Hg, and maximum cardiac output (m.c.o.) was measured by stepwise increase in the inflow of blood until no further rise in cardiac output occurred. The m.c.o. of enlarged hearts was above normal, but not if it was expressed per gram of left ventricle weight. This latter value was not above normal in any of the enlarged hearts, contrary to earlier findings in whole animals. In fact, in one group of severely anemic rats it was significantly below normal.

Effect of nutrition on growth and somatomedin A levels in the rat

1980 ◽  
Vol 94 (3) ◽  
pp. 321-326 ◽  
Author(s):  
Kazue Takano ◽  
Naomi Hizuka ◽  
Kazuo Shizume ◽  
Yoko Hasumi ◽  
Toshio Tsushima
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Normal Growth ◽  
Protein Diet ◽  
Low Protein Diet ◽  
High Fat ◽  
Low Protein ◽  
High Fat Diets ◽  
Hypophysectomized Rats ◽  
Fat Diets

Abstract. Serum somatomedin A was significantly reduced after 3 days of fasting in rats with a mean decrease of 23.6 ± 2.4% (N = 18) of initial values. Re-feeding for one day produced a definite increase in somatomedin A, with a rise in body weight. When re-fed isocalorically for 21 days with diets of different quality, a low protein diet led to smaller increases in both seum somatomedin A and body weight in comparison to those of control-, high-protein- and high fat-diets (P < 0.001). There is a positive correlation between the increase in body weight and serum somatomedin A levels (N = 70, r = 0.71, P< 0.001). The effect of growth hormone on somatomedin generation was abolished in hypophysectomized rats fed with low-protein diet. Our study suggests that protein in the diet is important for the generation of somatomedin A, which is necessary for normal growth.

THE ALDOSTERONE SECRETORY RESPONSE TO SODIUM RESTRICTION IN CHRONICALLY HYPOPHYSECTOMIZED CORTICOTROPHIN-MAINTAINED RATS AS A FUNCTION OF DURATION AND AMOUNT OF GROWTH HORMONE TREATMENT

1971 ◽  
Vol 50 (3) ◽  
pp. 407-411 ◽  
Author(s):  
M. PALKOVITS ◽  
W. de JONG ◽  
B. van der WAL ◽  
D. de WIED
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Treatment ◽  
Hormone Treatment ◽  
Secretory Response ◽  
Dependent Manner ◽  
Sodium Restriction ◽  
Hypophysectomized Rats ◽  
Synthetic Capacity ◽  
Dose Dependent

SUMMARY Daily administration of growth hormone (STH) to hypophysectomized rats treated with adrenal maintenance doses of corticotrophin restored the aldosterone secretory response (as measured by the synthetic capacity of the adrenal in vitro) to sodium restriction. Treatment with STH for the first 2 days after hypophysectomy or on the 7th day after hypophysectomy failed, but treatment during the 6th and 7th day after hypophysectomy with 100, 200 or 400 μg STH/day restored the aldosterone secretory response to sodium deprivation in a dose-dependent manner.

EFFECT OF HYPOPHYSECTOMY AND A LOW SODIUM DIET ON THE VOLUMES OF THE GLOMERULAR ZONE, FASCICULAR AND RETICULAR ZONES AND MEDULLA OF RATS

1965 ◽  
Vol 50 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Richard A. Miller
Keyword(s):  
Body Weight ◽  
Pars Distalis ◽  
Deficient Diet ◽  
Sodium Deficiency ◽  
Mean Values ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Direct Measurements ◽  
Hypophysectomized Rats ◽  
Made In

ABSTRACT Direct measurements of volume of the glomerular zone, fascicular and reticular zones and medulla were made in normal and hypophysectomized rats. All zones of the cortex and the medulla atrophied after hypophysectomy. However, while medullary and glomerular atrophy was proportional to the decrease in body weight, fascicular atrophy exceeded the loss in body weight. Hypertrophy of the glomerular zone occurred in rats fed a sodium deficient diet for 5 to 28 days beginning 14 days after hypophysectomy. Hence the volume of the glomerular zone is probably independent of the pars distalis, since the glomerular zone does not atrophy after hypophysectomy and can be stimulated to hypertrophy after it and the infundibular process are removed. Calculation of mass from areas in a mid-section by the Bahn formula and from direct measurements of volume yielded similar values for the mass of the fascicular zone. However, mean values for glomerular mass and for medullary mass were each significantly different. None the less, there was a high correlation between values, and the percent changes in mass of the glomerular zone resulting from the sodium deficiency were similar. Hence, the Bahn formula seems to be a useful shortcut procedure for detecting changes in the mass of the several regions of the cortex.

Optimal Adrenergic Support in Septic Shock Due to Peritonitis

2003 ◽  
Vol 98 (4) ◽  
pp. 888-896 ◽  
Author(s):  
Qinghua Sun ◽  
Zizhi Tu ◽  
Suzana Lobo ◽  
George Dimopoulos ◽  
Nathalie Nagy ◽  
...  
Keyword(s):  
Septic Shock ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
The Other ◽  
Control Group ◽  
Lower Blood

Background The authors evaluated optimal adrenergic support using norepinephrine, dopamine, and dobutamine in a clinically relevant model of septic shock. Methods Twenty-eight mature, female, anesthetized sheep (weight, 30.5 +/- 3.6 kg) underwent cecal ligation and perforation and were randomized into four groups of seven animals to be treated with norepinephrine, dopamine-norepinephrine, dobutamine-norepinephrine, or no adrenergic agent. In all groups, lactated Ringer's solution was administered to restore cardiac filling pressures to baseline. In the norepinephrine group, norepinephrine (0.5-5 microg. kg(-1). min(-1)) was titrated to maintain mean arterial pressure between 75-85 mmHg. In the dopamine-norepinephrine group, dopamine was given first, and norepinephrine was added only when mean arterial pressure remained below 75 mmHg despite the infusion of 20 microg. kg(-1). min(-1) dopamine. In the dobutamine-norepinephrine group, dobutamine was started at the same time as norepinephrine and titrated up to 20 microg. kg(-1). min(-1) to get a 15% increase in cardiac output. Results The dobutamine-norepinephrine group had greater cardiac output; superior mesenteric blood flow, oxygen delivery (Do(2)), and oxygen consumption ([OV0312]o(2)); and lower blood lactate concentration and partial pressure of carbon dioxide (Pco(2)) gap than the controls did. Cumulative urine output was significantly higher in the dobutamine-norepinephrine group than in the other groups. Survival time was significantly longer in the dobutamine-norepinephrine (24 +/- 4 h), dopamine- norepinephrine (24 +/- 6 h), and norepinephrine (20 +/- 1 h) groups than the control group (17 +/- 2 h; P &lt; 0.05 vs. other groups), and significantly longer in the combined dopamine-norepinephrine and dobutamine-norepinephrine groups (24 +/- 5 h) than in the norepinephrine alone group (P &lt; 0.05). Histologic examination of lung biopsies revealed less severe lesions in the dobutamine-norepinephrine group than in the control and norepinephrine alone groups. Anatomic alterations in the lung, liver, and small intestine were less severe in the dobutamine-norepinephrine group than in the other groups. Conclusions In this prolonged septic shock model, association of norepinephrine with either dopamine or dobutamine resulted in the longest survival and the least severe pulmonary lesions. The combination of dobutamine with norepinephrine was associated with a better myocardial performance, greater Do(2) and [OV0312]o(2), lower blood lactate concentration and Pco(2) gap, and less anatomic injury.

Effect of chronic administration of insulin on pituitary gland content of growth hormone in the normal rat

1970 ◽  
Vol 48 (2) ◽  
pp. 85-89 ◽  
Author(s):  
Robert L. Hazelwood ◽  
John G. Galaznik
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Young Adult ◽  
Pituitary Gland ◽  
Chronic Administration ◽  
Female Rats ◽  
Pituitary Glands ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Gland Content

Acetone-dried pituitary glands from young adult female rats (starting weight 165–168 g) previously injected (s.c.) with doses of insulin of 0.5 U to 1.0 U/kg body weight for 4 days, and then with 2.0 U/kg 6 days a week for an additional 34 days, were bioassayed in young hypophysectomized rats for growth hormone content. Insulin-injected rats gained significantly more weight than saline-injected controls. The tibia cartilage width of the insulin-injected donor rats was greater than that of control rats after 9, 17, 24, and 31 days of insulin; pituitary gland preparations from these insulin-injected rats increased tibia cartilage widths slightly but significantly over those of rats injected with control pituitary gland preparations.

THE INFLUENCE OF GROWTH HORMONE TREATMENT ON THYROID FUNCTION IN SWINE

1990 ◽  
Vol 70 (3) ◽  
pp. 991-995 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
P. A. THACKER ◽  
B. LAARVELD
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Key Words ◽  
Growth Hormone Treatment ◽  
Sampling Period ◽  
Hormone Treatment ◽  
Serum Concentrations ◽  
Significant Treatment ◽  
Blood Samples ◽  
To Receive

Twelve castrated male pigs of Yorkshire and Landrace breeding were selected at 95.9 ± 1.6 kg body weight (BW) and allocated equally to receive daily injections of either porcine growth hormone (pGH) at 90 μg kg−1 BW or vehicle buffer for four consecutive days. Following the last pGH injection, the pigs were infused via indwelling vena caval cannulae with thyrotropin-releasing hormone (TRH) at 0.5 μg kg−1 BW. Blood samples were obtained at 10 and 0 min before TRH and thereafter at 10-min intervals for 90 min. Serum concentrations of thyroxine and thyrotropin were lower (P < 0.06 and P < 0.1, respectively) but those of triiodothyronine higher (P < 0.01) in pGH-treated pigs throughout the sampling period. There were no significant treatment-by-time interactions indicating that the thyroid response to TRH was not influenced by pGH treatment. Key words: Swine, thyroid, growth hormone, somatotropin

MECHANISM OF ACTION OF GROWTH HORMONE IN ALTERING ITS OWN SECRETION RATE: COMPARISON WITH THE ACTION OF DEXAMETHASONE

1967 ◽  
Vol 56 (3) ◽  
pp. 499-509 ◽  
Author(s):  
Eugenio E. Muller ◽  
Shinji Sawano ◽  
Akira Arimura ◽  
Andrew V. Schally
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Treatment ◽  
Hormone Treatment ◽  
Secretion Rate ◽  
Dexamethasone Treatment ◽  
Considerable Decrease ◽  
Gh Secretion ◽  
Hypophysectomized Rats ◽  
Rate Comparison

ABSTRACT Administration of large doses of growth hormone (GH) (2 mg/100 g/day for 5 days) failed to modify growth hormone-releasing factor (GRF) activity in either 1) plasma and the hypothalamus of long-term hypophysectomized rats, 2) the hypothalamus of normal rats. An elevation of pituitary content of GH was observed in normal rats as a consequence of growth hormone treatment. In contrast to growth hormone, dexamethasone (50 μg/100 g/day for, 5 days) induced considerable decrease of GRF activity in both plasma and the hypothalamus of long-term hypophysectomized rats, as well as in the hypothalamus of normal rats. No alteration of pituitary GH content was observed in normal rats as a consequence of chronic dexamethasone treatment. GH (1 mg/100 g) given 30 minutes before administration of a hypothalamic extract blocked the GH-depleting activity of the latter, while dexamethasone (50 μg/100 g) given one hour before apparently was ineffective. It is suggested that growth hormone suppresses its own secretion rate acting directly on the pituitary gland, while the action of dexamethasone on GH secretion, takes place mainly at the level of the hypothalamus.

Circumstantial evidence for a role of the secretory pattern of growth hormone in control of body growth

1982 ◽  
Vol 99 (1) ◽  
pp. 24-30 ◽  
Author(s):  
John-Olov Jansson ◽  
Kerstin Albertsson-Wikland ◽  
Staffan Edén ◽  
Karl-Göran Thorngren ◽  
Olle Isaksson
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Replacement Therapy ◽  
Bone Growth ◽  
Injection Period ◽  
Longitudinal Bone Growth ◽  
Long Period ◽  
Hypophysectomized Rats ◽  
Secretory Pattern

Abstract. The effect of frequency of growth hormone (GH) administration on longitudinal bone growth and body weight was studied in hypophysectomized rats which were given replacement therapy with corticosteroids, thyroxine and GH with start of therapy on the day of surgery. Longitudinal bone growth, as determined by the tetracycline method, was measured during the last 5 days of the 9 day long period with replacement therapy. The daily replacement dose of GH (bGH-17:NIH) was 200 μg and was given on 1, 2, 4 or 8 occasions. Longitudinal bone growth was enhanced in the groups of animals receiving the hormone on two or more occasions per day. The most pronounced response was seen with an administration frequency of four times per day. Changes in body weight during the injection period showed similar changes. The results of the present study show that the administration frequency of growth hormone is important for the growth rate in hypophysectomized rats which have been given replacement therapy. The findings suggest that the secretory pattern of GH is an important factor for optimum growth.

Effect of growth hormone and thyroxine on growth and chemical composition of muscle, bone and other tissues in thyroidectomized-hypophysectomized rats

1959 ◽  
Vol 196 (4) ◽  
pp. 859-865 ◽  
Author(s):  
Robert O. Scow
Keyword(s):  
Growth Hormone ◽  
Chemical Composition ◽  
Growth Response ◽  
Pronounced Effect ◽  
The Other ◽  
Growth Hormone Administration ◽  
Hormone Administration ◽  
Other Hand ◽  
Hypophysectomized Rats ◽  
Accelerated Growth

Rats were thyroidectomized-hypophysectomized at weaning and 5 weeks later treated for 36 days with either growth hormone (0.1 or 0.5 mg/day), thyroxine (2.5 µg/day), or both. Growth hormone stimulated growth of all tissues whereas thyroxine accelerated growth of only muscle and certain viscera. The growth response of some tissues to thyroxine was as pronounced as that to growth hormone. Administration of thyroxine increased the response to growth hormone of only the tissues that grew when thyroxine was given alone. Although thyroxine had no effect on the amount of bone protein in growth hormone treated and untreated rats, it had a pronounced effect on the morphology (length and maturation) of bone. The amount of collagen in muscle increased with dosage of growth hormone; thyroxine had no effect on this response. Myosin, on the other hand, increased with growth hormone dosage only in those animals also given thyroxine. Thyroxine given alone increased myosin deposition in muscle but had no effect on collagen in muscle, bone or skin.

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