Dependence of tonin activity in rat submaxillary gland on growth hormone and testosterone.

1977 ◽  
Vol 232 (5) ◽  
pp. E522
Author(s):  
M Lis ◽  
R Boucher ◽  
M Chrétien ◽  
J Genest
Keyword(s):  
Growth Hormone ◽  
Angiotensin Ii ◽  
Specific Activity ◽  
Specific Binding ◽  
Combined Treatment ◽  
Submaxillary Gland ◽  
Female Rats ◽  
Male Rats ◽  
Angiotensin I ◽  
Sharp Drop

Tonin, an enzyme present in rat submaxillary gland, converts angiotensin I to angiotensin II and is able to form angiotensin II directly from renin substrates. This enzyme was previously shown to be different from renin, tissue isorenins, and angiotensin I converting enzyme. The specific activity of tonin in rat submaxillary gland increases with the age of the animal and is much higher in male than in female rats; this sex difference is apparent from 60 to 70 days of age. There is a sharp drop of tonin activity in hypophysectomized animals, whereas adrenalectomy, thyroidectomy, and gonadectomy have have little effect. The marked increase in tonin activity was observed in animals bearing MtT-F4 transplantable tumors known to produce ACTH, prolactin, and growth hormone. Tonin specific activity in hypophysectomized male rats is restored to control levels by combined treatment with growth hormone and testosterone. Prolactin alone or in combination with testosterone, as well as transplanted pituitaries, has no effect in hypophysectomized animals. There is a significant specific binding of 125I-labeled growth hormone to isolated membranes of rat submaxillary gland.

scholarly journals The Preventive Effects of Diminazene Aceturate in Renal Ischemia/Reperfusion Injury in Male and Female Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Maryam Malek ◽  
Mehdi Nematbakhsh
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Female Rats ◽  
Male Rats ◽  
Converting Enzyme ◽  
Diminazene Aceturate ◽  
Male And Female ◽  
Male And Female Rats

Background. Angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor (ACE2/Ang-1-7/MasR) appears to counteract most of the deleterious actions of angiotensin-converting enzyme/angiotensin II/angiotensin II receptor 1 (ACE/Ang II/AT1R) in renal ischemia/reperfusion (I/R) injury but ACE2 activity and its levels are sexually dimorphic in the kidney. This study was designed to evaluate the effects of activation endogenous ACE2 using the diminazene aceturate (DIZE) in renal I/R injury in male and female rats.Methods. 36 Wistar rats were divided into two groups of male and female and each group distinct to three subgroups (n=6). I/R group was subjected to 45 min of bilateral ischemia and 24 h of reperfusion, while treatment group received DIZE (15 mg/kg/day) for three days before the induction of I/R. The other group was assigned as the sham-operated group.Results. DIZE treatment in male rats caused a significant decrease in blood urea nitrogen (BUN), creatinine, liver functional indices, serum malondialdehyde (MDA), and increase kidney nitrite levels (P<0.05), and in female rats a significant increase in creatinine and decrease serum nitrite levels compared to the I/R group (P<0.05).Conclusions. DIZE may protect the male kidney from renal I/RI through antioxidant activity and elevation of circulating nitrite level.

Androgens and estrogens affect hepatic bile acid sulfotransferase in male rats

1985 ◽  
Vol 248 (6) ◽  
pp. G639-G642 ◽  
Author(s):  
R. B. Kirkpatrick ◽  
N. M. Wildermann ◽  
P. G. Killenberg
Keyword(s):  
Bile Acid ◽  
Chemical Structure ◽  
Specific Activity ◽  
Estrogen Treatment ◽  
Female Rats ◽  
Male Rats ◽  
Hepatic Bile ◽  
Similar Treatment ◽  
Untreated Female ◽  
Varied Chemical

The effect of estrogens and androgens on hepatic glycolithocholate sulfotransferase activity was studied in male rats. Significant increases in specific activity were noted following treatment of rats for 21 days with 17 beta-estradiol, 17 alpha-ethynylestradiol, and the nonsteroidal estrogen agonists nafoxidine, tamoxifen, and diethylstilbestrol. Similar treatment of male rats with 5 alpha-dihydrotestosterone, hydrocortisone, norethindrone, and prolactin did not affect activity. To further assess the effect of androgens, male rats were castrated. Glycolithocholate sulfotransferase activity increased fivefold by 14 days after castration. Treatment of castrated rats with 5 alpha-dihydrotestosterone prevented the increase and maintained activity at the level of sham-operated animals. Castrated animals exhibited an additional increment in activity following treatment with 17 alpha-ethynylestradiol: specific activity in these animals rose to levels comparable with those measured in untreated female rats. These data suggest endogenous androgens maximally suppress hepatic glycolithocholate sulfotransferase activity in male rats. The data also indicate that activity is stimulated by estrogenic compounds of varied chemical structure and that stimulation is not solely due to suppression of androgen release by the testes as a consequence of estrogen treatment.

FACTORS INFLUENCING THE EXCRETION OF A FAT-MOBILIZING SUBSTANCE IN THE URINE OF RATS

1966 ◽  
Vol 44 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J. R. Beaton ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson
Keyword(s):  
Body Weight ◽  
Sex Difference ◽  
Specific Activity ◽  
Young Male ◽  
Total Activity ◽  
Female Rats ◽  
Male Rats ◽  
Diabetic Rat ◽  
Adult Rats ◽  
Factors Influencing

The effect of various factors on excretion of a lipid-mobilizing activity in FMS IA (anorexigenic) and in FMS IB (fat-mobilizing) by the fasting rat has been investigated. During fasting, the greatest excretion of such activity in FMS IA and FMS IB occurred in the first 24 hours and diminished thereafter up to 72 hours; and the specific activity of FMS IB was greatest in the first 24 hours whereas that of FMS IA was constant throughout. The hypothalamicobese rat excretes FMS IA and FMS IB in greater than normal amounts. The alloxan-diabetic rat excretes less total activity of FMS IA and IB than do control animals. Young male rats excrete greater amounts of FMS IB, but not of FMS IA, than do adult rats, the greatest excretion per 100 g body weight being observed at approximately 37 days of age. At 27 days of age (prepuberty), male rats excreted a greater total activity of FMS IB but not of FMS IA than did female rats. At 90 days of age (post-puberty), there was no apparent sex difference in the amount of total activity of FMS IB excreted per rat, but when expressed per 100 g body weight, females excreted more FMS IB than did males.

Cytoplasmic estrogen, but not progestin, binding sites in male rat adipose tissues

1980 ◽  
Vol 239 (4) ◽  
pp. E237-E237
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Adipose Tissues ◽  
Body Fat Content ◽  
Estrogen Binding ◽  
Fat Pads

Male rat adipose tissues contain cytoplasmic estrogen binding sites comparable to those found in females. This bindng is of high affinity (Kd = 1.7 x 10(-10) M) and is estrogen specific. Binding of 17 beta-estradiol was inhibited by radioinert estrogens (17 beta-estradiol and R 2858) but not by other steroids (progesterone, 5 alpha-dihydrotestosterone, and corticosterone). Estrogen binding sites were found in all fat pads studied, but levels were highest in the epididymal pads. Treatment of female rats with 17 beta-estradiol benzoate (E2B) induced cytoplasmic progestin receptors in adipose tissues, but in three separate experiments, E2B treatment (20 microgram/day for 3 days) failed to induce measurable progestin ([3H]R 5020) binding sites in males. E2B treatment reduced lipoprotein lipase (LPL) activity by approximately 75% in epididymal (male) and parametrial (female) fat pads. Concurrent progesterone treatment increased parametrial LPL activity in E2B-treated females, but progesterone had no effect on epididymal fat pad LPL activity in males. These findings are consistent with the hypothesis that in male rats aromatized (estrogenic) metabolites of testosterone may reduce body fat content and alter lipid metabolism by direct actions on adipose tissues.

INFLUENCE OF SEX HORMONES ON AMIDINOTRANSFERASE LEVELS. METABOLIC CONTROL OF CREATINE BIOSYNTHESIS

1966 ◽  
Vol 53 (4) ◽  
pp. 655-662 ◽  
Author(s):  
István Kriskó ◽  
James B. Walker
Keyword(s):  
Testosterone Propionate ◽  
De Novo ◽  
Specific Activity ◽  
Hormonal Control ◽  
Mature Male ◽  
Female Rats ◽  
Male Rats ◽  
Enzyme Protein ◽  
Wet Weight ◽  
Mammalian Enzyme

ABSTRACT Arginine: glycine amidinotransferase is the first of two enzymes involved in creatine biosynthesis. The amidinotransferase specific activity (micromoles of hydroxyguanidine formed per hour per g wet weight of tissue) of kidney homogenates of mature male rats was about twice that of females of the same age, whereas activities were equal before puberty. Castration decreased the activity of males and increased that of females. The administration of testosterone propionate to young adult female rats resulted in a significant increase in enzyme activity. The same enzyme had previously been shown to be repressible by its end-product, creatine. Although there are numerous enzymes whose synthesis is known to be under hormonal control, amidinotransferase is the only mammalian enzyme described up to now on which there appears to operate both an end-product repression mechanism and a hormonal control on the de novo synthesis of the enzyme protein.

scholarly journals Sex-dependent expression and growth hormone regulation of class alpha and class mu glutathione S-transferase mRNAs in adult rat liver

1993 ◽  
Vol 294 (1) ◽  
pp. 159-165 ◽  
Author(s):  
P K Srivastava ◽  
D J Waxman
Keyword(s):  
Growth Hormone ◽  
Continuous Infusion ◽  
Rat Liver ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Glutathione S Transferase ◽  
Gh Treatment ◽  
Adult Rat ◽  
Hypophysectomized Rats

The sex-dependent expression and growth hormone (GH) regulation of rat liver glutathione S-transferase (GST) was examined using oligonucleotide probes that distinguish between closely related class Alpha (Ya1, Ya2, Yc) and class Mu (Yb1, Yb2, Yb3) GST mRNAs [Waxman, Sundseth, Srivastava and Lapenson (1992) Cancer Res. 52, 5797-5802]. Northern-blot analysis revealed that the steady-state levels of GST Ya1, Yb1 and Yb2 mRNAs are 2.5-3-fold higher in male as compared with female rat liver. In contrast, GST Yc and Ya2 mRNAs were expressed at a 2-3-fold higher level in female rat liver. Microsomal GST mRNA did not exhibit significant sex-dependent differences in rat liver. Treatment of male rats with GH by continuous infusion suppressed expression of the male-dominant GST Ya1, Yb1 and Yb2 mRNAs to levels at or below those found in female rat liver. This suppressive effect of GH was liver-specific, insofar as GH treatment did not alter kidney GST Ya1 mRNA levels. Hypophysectomy increased expression of the male-dominant GSTs, particularly in female rats (e.g. 8-fold elevation of GST Ya1 mRNA). GST Yc mRNA was increased approx. 2-fold in hypophysectomized males, indicating that this mRNA is subject to negative regulation by one or more pituitary-dependent factors. Continuous GH treatment of the hypophysectomized rats suppressed the expression of mRNA of GSTs Ya1, Yb1 and Yb2 when given as a continuous infusion, but not when given by an intermittent (twice daily) GH-injection schedule. Combination of continuous exposure to GH with thyroxine treatment resulted in a more complete suppression of GSTs Ya1, Yb1 and Yb2. In contrast, thyroxine increased the expression of GST Yc in hypophysectomized rats. These studies establish that several Alpha and Mu class GSTs are expressed in a sex-dependent fashion in adult rat liver, where they are regulated by multiple pituitary-dependent hormones through pretranslational mechanisms.

THE INTERRELATION OF THE GROWTH AND METABOLIC RESPONSES TO ANTERIOR PITUITARY GROWTH HORMONE ADMINISTRATION

1957 ◽  
Vol 35 (1) ◽  
pp. 1113-1118
Author(s):  
George H. Beaton ◽  
Hannah Z. Banky ◽  
Audrey M. Haufschild
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Amino Nitrogen ◽  
The Body ◽  
Female Rats ◽  
Male Rats ◽  
Weight Increase ◽  
Metabolic Alterations ◽  
Nitrogen Levels ◽  
Body Weight Increase

Doses of growth hormone which were minimal with respect to body weight increase were sufficient to produce significant alterations in liver alanine – glutamic transaminase and arginase activities and blood urea and amino nitrogen levels. The biochemical effects of the hormone appeared coincident with the body weight increase. Female rats showed a more pronounced response to growth hormone than did male rats. This sex difference was evident with respect to all of the metabolic alterations observed. Although it is not possible to state whether the metabolic alterations are direct effects of the hormone, they do take an integral part in bringing about the over-all biological effect.

125I-LABELLING OF ANGIOTENSIN I AND II

1971 ◽  
Vol 67 (1) ◽  
pp. 104-116 ◽  
Author(s):  
Meta Damkjær Nielsen ◽  
Mogens Jørgensen ◽  
Jørn Giese
Keyword(s):  
Angiotensin Ii ◽  
Paper Chromatography ◽  
Enzymatic Degradation ◽  
Specific Activity ◽  
Simple Procedure ◽  
Enzymatic Conversion ◽  
Purification Step ◽  
Angiotensin I ◽  
Low Concentrations ◽  
Chloramine T

ABSTRACT A simple procedure for a reproducible preparation of radioiodinated angiotensin analogues is described. The iodination is performed at a low level of radioactivity – 200 μCi per 10 μg peptide – with low concentrations of chloramine-T and sodium metabisulphite. No destruction of the peptide occurs during the iodination. The yield is high, and the only purification step needed is a separation of iodinated peptide from non-labelled peptide. This separation is performed by means of column chromatography on DEAE-Sephadex A 25. The specific activity of labelled angiotensin I or II prepared by this method was about 500 μCi/μg. The homogeneity of the radioiodinated angiotensin analogues was established by means of paper chromatography and enzymatic degradation studies, including experiments on the enzymatic conversion of 125I-angiotensin I to 125I-angiotensin II. Radiochromatograms obtained after storage for various periods showed perfect stability of the labelled compounds. Immunological characteristics, as evaluated by standard displacement curves with selected antisera and maximal binding to excess antibody, were reproducible from batch to batch.

scholarly journals Reduction of renal dopamine receptor expression in obese Zucker rats: role of sex and angiotensin II

2010 ◽  
Vol 299 (5) ◽  
pp. F1164-F1170 ◽  
Author(s):  
Xiaoyan Wang ◽  
Fengmin Li ◽  
Pedro A. Jose ◽  
Carolyn M. Ecelbarger
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Receptor Expression ◽  
Female Rats ◽  
Male Rats ◽  
Zucker Rats ◽  
Protein Levels ◽  
Obese Rats ◽  
Obese Zucker Rats

Dopamine produced by renal proximal tubules increases sodium excretion via a decrease in renal sodium reabsorption. Dopamine natriuresis is impaired in obese Zucker rats; however, the mechanism is not fully understood. To test the hypothesis that renal expression of one or more of the subtypes are altered in these rats, we measured whole kidney protein levels by immunoblotting of D1-like (D1R and D5R) and D2-like (D2R, D3R, and D4R) dopamine receptors in both male and female obese and lean Zucker rats. In obese males on 1% NaCl diet, D1R, D2R, D4R, and D5R were decreased, while D3R was increased, relative to lean rats. Under a 4% NaCl diet, D2R and D3R levels in obese rats were restored to lean levels. 4% NaCl diet reduced D5R in both body types, relative to 1% NaCl diet. Female rats had higher expression of D1R and D3R than did male; however, the sex difference for D1R was markedly blunted in obese rats. In obese rats, dietary candesartan (angiotensin II type 1 receptor blocker) normalized downregulated D1R and D2R, but either decreased (D3R), did not affect (D4R), or further downregulated (D5R) the other subtypes. Candesartan also decreased D4R in lean rats. In summary, reduced renal protein levels of D1R, D2R, D4R, and D5R in obese Zucker rats could induce salt sensitivity and elevate blood pressure. Increased angiotensin II type 1 receptor activity may be mechanistically involved in the decreased expression of D1R and D2R in obese rats. Finally, reduced D1R and D3R in male rats may contribute to sex differences in blood pressure.

Growth hormone responses to multiple injections of a fragment of human growth hormone-releasing factor in conscious male and female rats

1985 ◽  
Vol 106 (3) ◽  
pp. 281-289 ◽  
Author(s):  
R. G. Clark ◽  
I. C. A. F. Robinson
Keyword(s):  
Growth Hormone ◽  
Human Growth ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Male And Female ◽  
Gh Secretion ◽  
Male And Female Rats ◽  
Hormone Responses ◽  
Males And Females

ABSTRACT The GH responses to single i.v. injections of GH-releasing factor (GRF) in conscious male rats are highly variable. Although normal male rats show a pulsatile secretory pattern of GH with pulses occurring at intervals of 3–3·5 h, the peaks occur at different times in individual animals. We have compared the GH responses of young conscious male and female rats to multiple i.v. injections of 1 μg human (h) GRF1-29NH2. The peak GH responses occurred 3–5 min after hGRF1-29NH2 injection and were lower in female than in male rats. Both males and females responded uniformly to hGRF1-29NH2 injections given 180 min apart and the GH responses became entrained with no endogenous GH pulsing. Female rats produced consistent GH peaks in response to hGRF1-29NH2 injections at 90-min intervals, whereas male rats responded only to alternate injections, so that GH peaks occurred only every 180 min despite giving GRF every 90 min. When the frequency of hGRF1-29NH2 administration was increased to once every 40 min female rats again responded consistently to each injection. Male rats responded intermittently, being able to respond to two injections 40 min apart, after which they became refractory to hGRF1-29NH2. This cycle of varying sensitivity to GRF in male rats probably underlies their 3-hourly endogenous GH secretory rhythm. Female rats can respond uniformly to repeated GRF injections, consistent with their more continuous pattern of endogenous GH secretion. Introducing a pulse of 10 μg rat GH into a series of hGRF1-29NH2 injections did not induce refractoriness to hGRF1-29NH2, suggesting that GH does not itself desensitize the pituitary to GRF. Whether the different patterns of GH secretion in males and females result from different patterns of GRF and/or somatostatin secretion remains to be determined. J. Endocr. (1985) 106, 281–289

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