Growth and bone haemodynamic responses to castration in male rats. Reversibility by testosterone

Abstract. Orchidectomy in postpubertal 55 day old rats, compared to sham-operated controls, led beyond 2 months to a decrease in body weight (87% of controls by 120 d), tibial length (97% of controls) and in tibial calcium content (85% of controls). Bone plasma flow increased three times to reach a peak at 31 days; it was decreased but no significantly at 86 and 120 days. The number of oosteoclasts was maximal at 51 days (X 2.3) and was still elevated at 120 days. The calcium accretion rate increased briefly at 31 days (110% of controls) and was diminished at 86 and 120 days (78% of controls). The initial 'physiological' changes in the tibia occurred before any weight change and might be directly due to the lack of androgens. They can be interpreted as inducing the conditions for enhanced bone resorption. Testosterone replacement therapy, initiated after the initial haemodynamic response, inhibited the negative effect of castration on bone growth.

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Evidence for genomic and nongenomic actions of estrogen in growth plate regulation in female and male rats at the onset of sexual maturation

Journal of Endocrinology ◽

10.1677/joe.0.1750277 ◽

2002 ◽

Vol 175 (2) ◽

pp. 277-288 ◽

Cited By ~ 24

Author(s):

BC van der Eerden ◽

J Emons ◽

S Ahmed ◽

HW van Essen ◽

CW Lowik ◽

...

Keyword(s):

Body Weight ◽

Weight Gain ◽

Growth Plate ◽

Sexual Maturation ◽

Body Weight Gain ◽

Male Rats ◽

Longitudinal Growth ◽

Zone Width ◽

Tibial Length ◽

Plate Width

Recently, both estrogen receptor (ER) alpha and beta were detected in growth plate chondrocytes of rats before sexual maturation, implying a role for estrogen at this stage. In this study, therefore, we investigated the effects of ovariectomy (OVX) or estrogen supplementation on parameters of longitudinal growth in 26-day-old rats, which were sexually immature at the start of the experiment. OVX caused an increase in body weight gain, tibial length and growth plate width due to an increased proliferating zone. This increase correlated with an increase in cell number, with a decrease in cell diameter and with increased proliferating cell nuclear antigen (PCNA) immunostaining compared with sham. Interestingly, the increase in proliferation was not caused by an increase in insulin-like growth factor-I (IGF-I) mRNA expression in the growth plate as assessed by real-time PCR. In contrast to OVX, 17beta-estradiol (E(2)) supplementation (0.5 mg/21 days) of 26-day-old female rats caused a strong decrease in body weight gain, tibial length and growth plate width. The latter was explained by a reduction of the proliferating zone width, which correlated with a reduced number of PCNA-positive cells (not significant) and by a reduction of the hypertrophic zone width. In male rats supplemented with E(2), similar effects were observed compared with the females. ERalpha and beta immunostaining was found predominantly in late proliferating and early hypertrophic chondrocytes. OVX did not affect ER expression but E(2) supplementation strongly decreased immunostaining for both ERalpha and beta in both sexes. Besides E(2), desoxyestrone (DE), an activator of nongenomic estrogen-like signaling (ANGEL) and 2-methoxyestradiol (2-MeO-E(2)), a tissue-selective naturally occurring metabolite of E(2), were administered to female and male rats of the same age. Compared with E(2), these compounds had less pronounced, though significant, effects on some parameters of longitudinal growth in both sexes, especially on growth plate characteristics. In conclusion, E(2) may exert effects on longitudinal growth before and at the onset of sexual maturation, despite very low endogenous serum levels at these stages. There may be a role for nongenomic signaling in body weight gain, tibial length and growth plate width but genomic signaling prevails.

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Long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats

British Journal Of Nutrition ◽

10.1079/bjn20051407 ◽

2005 ◽

Vol 93 (5) ◽

pp. 613-618 ◽

Cited By ~ 33

Author(s):

Takahiro Kawasaki ◽

Akiko Kashiwabara ◽

Tadashi Sakai ◽

Kanji Igarashi ◽

Nobuyuki Ogata ◽

...

Keyword(s):

Body Weight ◽

Glucose Intolerance ◽

Plasma Glucose ◽

Male Rats ◽

Control Group ◽

Normal Male ◽

Oral Glucose ◽

Old Rats ◽

Sucrose Drinking

The current epidemic of diabetes likely reflects marked changes in environmental factors, although genetic susceptibility plays a powerful role in the occurrence of diabetes in certain populations. We investigated whether long-term sucrose-drinking causes hyperglycaemia in male Wistar-Imamichi littermates (n 32), which are not genetically susceptible to diabetes or obesity. Each litter was divided equivalently into two groups, the sucrose group and the control group. The sucrose group received 300 g/l sucrose water and the control group received regular water until 42 weeks of age. Rats were weighed every 1 or 2 weeks. Oral glucose tolerance tests were performed at 28 and 36 weeks of age. Plasma glucose and insulin concentrations were measured. Body weights were significantly greater in the sucrose group than in the control group in 18-week-old rats (P<0·05), and the difference between the two groups reached 163 g by the end of the study (P<0·01). The 120 min post-load plasma glucose concentration in the sucrose group was 11·4 (sd 2·8) mmol/l in 28-week-old rats and 12·7 (sd 2·2) mmol/l in 36-week-old rats, while that of the control group remained approximately 7·3–7·7 mmol/l. In the sucrose group, the plasma insulin peak occurred 30 min post-load at 28 weeks of age; but the peak disappeared and hyperinsulinaemia was prolonged at 36 weeks of age. In conclusion, long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats.

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Effects of 4-Hexylresorcinol on Craniofacial Growth in Rats

International Journal of Molecular Sciences ◽

10.3390/ijms22168935 ◽

2021 ◽

Vol 22 (16) ◽

pp. 8935

Author(s):

In-Song Lee ◽

Dae-Won Kim ◽

Ji-Hyeon Oh ◽

Suk Keun Lee ◽

Je-Yong Choi ◽

...

Keyword(s):

Body Weight ◽

Histone Deacetylase Inhibitor ◽

High Performance ◽

Food Additive ◽

Female Rats ◽

Male Rats ◽

Craniofacial Growth ◽

Growing Rats ◽

Deacetylase Inhibitor ◽

Old Rats

4-Hexylresorcinol (4HR) has been used as a food additive, however, it has been recently demonstrated as a Class I histone deacetylase inhibitor (HDACi). Unlike other HDACi, 4HR can be taken through foods. Unfortunately, some HDACi have an influence on craniofacial growth, therefore, the purpose of this study was to evaluate the effects of 4HR on craniofacial growth. Saos-2 cells (osteoblast-like cells) were used for the evaluation of HDACi and its associated activities after 4HR administration. For the evaluation of craniofacial growth, 12.8 mg/kg of 4HR was administered weekly to 4 week old rats (male: 10, female: 10) for 12 weeks. Ten rats were used for untreated control (males: 5, females: 5). Body weight was recorded every week. Serum and head samples were collected at 12 weeks after initial administration. Craniofacial growth was evaluated by micro-computerized tomography. Serum was used for ELISA (testosterone and estrogen) and immunoprecipitation high-performance liquid chromatography (IP-HPLC). The administration of 4HR (1–100 μM) showed significant HDACi activity (p < 0.05). Body weight was significantly different in male rats (p < 0.05), and mandibular size was significantly smaller in 4HR-treated male rats with reduced testosterone levels. However, the mandibular size was significantly higher in 4HR treated female rats with increased growth hormone levels. In conclusion, 4HR had HDACi activity in Saos-2 cells. The administration of 4HR on growing rats showed different responses in body weight and mandibular size between sexes.

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THE EFFECT OF AGEING ON THE NUMBER OF THE ISLETS OF LANGERHANS IN THE RAT

Acta Endocrinologica ◽

10.1530/acta.0.xxxii0078 ◽

1959 ◽

Vol XXXII (I) ◽

pp. 78-91 ◽

Cited By ~ 19

Author(s):

Bo Hellman

Keyword(s):

Body Weight ◽

Age Groups ◽

The Body ◽

Male Rats ◽

Quantitative Relation ◽

List Type ◽

Positive Correlation ◽

Islet Volume ◽

Old Rats ◽

Lower Size

ABSTRACT Information concerning the so called 'total number' of islets is inexact. The number of islets should instead be expressed as that number which exceeds a well defined and easily identifiable lower size boundary. Studies on the numerical distribution of the islets show, in a comparison between two animals, that while the same lower size limit must be set in each case, considerable latitude may be exercised in selecting its actual value without disturbing the results. In this investigation only those islets, whose diameter was equal to or exceeded 46.9 μ were counted. The effect of ageing on the number of islets has been studied in a total of 75 male rats, which were nourished on a diet well defined calorically. The rats were killed on the 1st, 5th, 21st, 100th and 480th days of life. The following observations were made: With increase in age there was a marked increase in the number of islets. The value in the oldest animals was on the average more than 13 times that in the new-born. If the number of islets is expressed in relation to the total body weight or the weights of liver or pancreas, the ratio is markedly reduced with increasing age. The 480 days old rats were, however, an exception, as the values for this age showed a statistically significant increase as compared with 100 days old rats. When plotted in a double logarithmic co-ordinate system the liver and pancreatic weights were linear functions of the body weight in all the age groups studied. The corresponding regression between the islet number and the body weight was, however, curvilinear, so that the rate of increase was initially slow (between 0–5 days) but between the two oldest groups (100 and 480 days) it approached that of the pancreatic and liver weights. In each age group there is a strongly positive correlation between the number of islets and the total islet volume. In most of the age groups there was statistical support for a positive correlation between body weight and number of islets. Within the different age groups a quantitative relation between the number of islets and the weight of the pancreas was not apparent after the common positive correlation with the body weight had been eliminated by calculating the partial correlations. The regular mathematical arrangement of the islet tissue makes it possible to determine the actual number of islets by only counting the number of islet section surfaces which exceed a certain defined size.

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CHANGES IN THE LEVELS OF LUTEINIZING HORMONE AND TESTOSTERONE IN THE CIRCULATION OF AGEING MALE RATS

Journal of Endocrinology ◽

10.1677/joe.0.0760551 ◽

1978 ◽

Vol 76 (3) ◽

pp. 551-552 ◽

Cited By ~ 50

Author(s):

G. D. GRAY

Keyword(s):

Complex Interaction ◽

Male Rats ◽

Hormonal Changes ◽

Physiological Changes ◽

Functional Relationships ◽

School Of Medicine ◽

Age Related ◽

Ageing Male ◽

Old Rats ◽

Time Information

Department of Physiology, Stanford University School of Medicine, Stanford, California 94305, U.S.A. (Received 26 September 1977) Pituitary-testicular function changes substantially with increasing age in male rats; the levels of testosterone and gonadotrophins in the circulation are reduced in old animals (Ghanadian, Lewis & Chisholm, 1976; Riegle & Meites, 1976; Chan, Leathem & Esashi, 1977). However, previous studies compared only young and very old rats (more than 18 months) and the development of age-related changes in the concentrations of testosterone and gonadotrophins has not been examined. Since ageing is a complex interaction of physiological changes over a prolonged period of time, information on the precise timing of the various changes is important in establishing functional relationships in the ageing process. This study investigates hormonal changes in a group of male rats between 8 and 21 months old. Adult male Long–Evans rats were housed three/cage in a temperature-controlled room with a 14

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The Effect of Periodic Exercise and Resveratrol Supplementation on the Expression of Pparg Coactivator-1 Alpha and Pyruvate Dehydrogenase Kinase Genes in Gastrocnemius Muscle of Old Rats With Type 2 Diabetes

Quarterly of Horizon of Medical Sciences ◽

10.32598/hms.26.1.3145.1 ◽

2020 ◽

Vol 26 (1) ◽

pp. 68-81

Author(s):

Ali Salehi ◽

◽

Hajar Abbaszadeh ◽

Parvin Farzanegi ◽

◽

...

Keyword(s):

Type 2 Diabetes ◽

Body Weight ◽

Pyruvate Dehydrogenase ◽

Gastrocnemius Muscle ◽

Diabetic Control ◽

Pyruvate Dehydrogenase Kinase ◽

Male Rats ◽

Expression Levels ◽

Old Rats

Aims: Type 2 diabetes is the result of complex interactions between genetic and environmental factors that affect fat and glucose metabolism. The purpose of this study was to determine the effect of periodic exercise and resveratrol supplement on the expression levels of Pparg Coactivator 1-Alpha (PGC-1α) and Pyruvate Dehydrogenase Kinase (PDK4) genes in gastrocnemius muscle of old rates with type 2 diabetes. Methods & Materials: 42 male rats (mean age= 40-50 weeks; mean body weight= 250-300 g) were randomly divided into 6 groups: healthy-control, diabetic-control, Diabetic+Periodic Exercise, Diabetic+Supplement, Diabetic+Periodic Exercise+Supplement and Saline. The type 2 diabetes was induced by intraperitoneal injection of Streptozotocin (50 mg/kg body weight). The exercise protocol consisted of 10 sets of 1-min activities at 50% intensity and a 2-min rest period between sets, and each week the speed was increased by 2 meters per minute. The exercises were performed for eight weeks. Resveratrol supplement was injected intraperitoneally daily at a dose of 20 mg/kg body weight. The expressions of PDK4 and PGC-1α in the gastrocnemius muscle were measured by real time Polymerase Chain Reaction (PCR) method. Findings: highest expression level of PDK4 and PGC-1α genes in gastrocnemius muscle was observed in the diabetic group received both periodic exercise and Resveratrol supplement and the lowest level was reported in the diabetic-control and saline groups. Conclusion The combination of resveratrol supplementation and periodic exercise can have beneficial effects on PDK4 and PGC-1α expression levels in the gastrocnemius muscle of old rats with type 2 diabetes and reduce the risks of diabetes-related complications.

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Manipulation of androgens causes different energetic responses to cold in 60- and 40-day-old male rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2001.280.1.r262 ◽

2001 ◽

Vol 280 (1) ◽

pp. R262-R273 ◽

Cited By ~ 14

Author(s):

Francisca Gomez ◽

Mary F. Dallman

Keyword(s):

Body Weight ◽

Partial Resistance ◽

Room Temperature ◽

High Sensitivity ◽

Male Rats ◽

Positive Effects ◽

Old Rats ◽

Resistance To Stress ◽

Almost All

Previous studies suggested that adults respond differently than pubertal male rats to cold stress. To test the role of androgens in this difference, we adrenalectomized and replaced with corticosterone either 60- or 40-day-old male rats, then sham gonadectomized (Intact), gonadectomized (GDX), or GDX and replaced with testosterone (T; GDX+T) or dihydrotestosterone (DHT). One-half remained at room temperature (RT), and one-half lived in cold for 5 days. Cold reduced T in adult but not in pubertal Intacts. In 60-day-old rats, GDX with or without T replacement had minor effects on body weight (BW) and food intake (FI) at RT and cold. In 40-day-old rats at RT, androgens had slight effects; however, androgens affected almost all variables in cold. Separation of 40-day-old T-treated rats into two groups (moderate T levels, 1.4 ng/ml; high T levels, 1.9 ng/ml) revealed major differences between the groups. Moderate T (and DHT) prevented cold-induced loss of BW and increased FI. No T and high T induced decreased BW and FI in cold. We conclude that at 40 days of age, partial resistance to stress-induced reduction of T and high sensitivity to small changes in T have markedly positive effects on threatened energy balance.

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Long-term Behaviour of 239Pu, 241Am and 233U in Different Bones of One-year-old Rats: Macrodistribution and Macrodosimetry

Human Toxicology ◽

10.1177/096032718400300602 ◽

1984 ◽

Vol 3 (6) ◽

pp. 469-483 ◽

Cited By ~ 17

Author(s):

W. Sontag

Keyword(s):

Body Weight ◽

Relative Concentration ◽

Female Rats ◽

Male Rats ◽

Sprague Dawley ◽

Old Rats ◽

One Year ◽

The Individual ◽

Suitable Reference

1 Female and male rats of the Sprague-Dawley strain, aged about 13 months, were injected intravenously with monomeric 239Pu-(30.7 kBq/kg), 241Am-(54.8 kBq/kg) or 233U-citrate (56.6 kBq/kg) and killed between 7 and 540 days after injection. 2 In both sexes the wet skeletal weight was proportional to body weight; however, the skeletal weight of female rats remained constant, whereas the skeletal weight, and body weight, of male rats increased as a function of age. 3 The initial skeletal deposition decreased in the order 239Pu > 241Am > 233U and for americium and uranium was greater in male rats. The 'half-time' of retention of plutonium and americium was considerably greater than 1 year but the corresponding values for uranium were 140 (females) and 80 (males) days. 4. The relative concentration of the radionuclides in the skeleton varied between 0.2 and 2.0, the variation was greatest for plutonium and lowest for americium and decreased with increasing time after injection. 5 For calculation of the nuclide content of the whole skeleton the most suitable reference bone was found to be the humerus in the case of uranium, and the femur and humerus for plutonium and americium. 6 The cumulative mean skeletal absorbed radiation dose 1 year after injection decreased in the order 239Pu > 241 Am > 233U; for plutonium it was equal for both sexes, whereas for americium and uranium it was 1.5 times higher in male than in females rats. In the individual bones the cumulative dose was greatest in the vertebral column, except the tail, and lowest in the paws.

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